High-voltage composite mosfet and high-voltage amplifier using the same in output stage circuit of high-voltage amplifier

Abstract

To solve a problem that a high-voltage mosFET has a large gate input capacitance, and therefore, there is a limit to high-speed and wideband operation of a high-voltage amplifier using the high-voltage mosFET.SOLUTION: A high-voltage composite mosFET having a gate of a low input capacitance and a source of a low input impedance is devised and applied to a high-voltage amplifier using the high-voltage mosFET. In addition, a circuit for driving a high impedance gate of the composite-type mosFET by the low impedance source of the composite-type mosFET paired with a positive-side output stage and a negative-side output stage of a high-voltage amplification part with respect to an output via a capacitor is added to a high-voltage amplification circuit. Further, the high-voltage composite mosFET having a high performance by adding a capacitor for preventing a transmission has achieved a high-speed and a wideband operation of a stable high-voltage amplifier without increasing a power loss.SELECTED DRAWING: Figure 2-1

Description

[Technical Field]

[0001] This paper deals with high-voltage composite mosFETs and high-voltage amplifiers. [Background technology]

[0002] The breakdown voltage of commercially available high-voltage mosFETs is at most a few kV, so when using such mosFETs to create a high-voltage amplifier that outputs a voltage higher than the breakdown voltage, Multiple high-voltage MOS FETs are connected in series in multiple stages between the high-voltage power supply and the output terminal, and the voltage applied to the MOS FETs in each stage is changed in response to the changing input signal, which is then amplified to a specified value and output. At this time, it is necessary to control the gates of these mosFETs at high speed so that the voltage applied to the mosFETs in each stage is always divided evenly so that it is below the withstand voltage.

[0003] However, the high-voltage mosFETs in each stage, to which a voltage of several kV is applied, change their voltage over a wide range from 0 to several kV in response to the input signal, and are adversely affected by the Miller effect, which increases in proportion to the width of this voltage change, making it difficult to drive the input capacitance at the gates of these mosFETs at high speed.As a result, conventional high-voltage amplifiers have had the problem that the higher the output voltage and the greater the number of high-voltage mosFETs connected in series, the more difficult it is to achieve high speed and wide bandwidth, resulting in a narrower bandwidth.

[0004] Patent Document 1 describes a technique that attempts to solve this problem. Specifically, as shown in Figure 3 of the document, the gate of a high-voltage mosFET Q1 with a large input capacitance is driven by a push-pull circuit consisting of a low-voltage n-channel mosFET Q2 with a small gate input capacitance and a p-channel mosFET Q3. However, when the output changes with a large amplitude, this push-pull circuit experiences a state in which both p-channel and n-channel mosFETs become inoperative at the moment when their operation switches, resulting in unstable operation and limiting the ability to achieve high speeds and wide bandwidths.

[0005] FIG. 1-1 shows an example of a basic circuit of a conventional high-voltage amplifier, which is the basic circuit of the high-voltage amplifier of the present invention shown in FIG. 2-1 and subsequent figures. In Figure 1-1, the positive output stage between the +2100V high-voltage power supply +HVps and the output terminal, which is provided in the high-voltage amplification section of the high-voltage amplifier, and the negative output stage between the -2100V high-voltage power supply -HVps and the output terminal, are both connected in two stages in series to form a ±2kV output high-voltage amplifier (amplifier gain is 200 times) using high-voltage n-channel mosFETs Q102, Q101, Q202, and Q201. The signal input to the low-voltage amplifier is amplified by operational amplifier U1, and the source current is controlled by the positive output stage of the high-voltage amplifier via photocoupler U101, and the sink current is controlled by the negative output stage of the high-voltage amplifier via photocoupler U201, and the signal is amplified to a high voltage.

[0006] Resistors R2 and R1 of predetermined resistance values ​​connected to the output terminal negatively feed back the output voltage to the operational amplifier U1 in the low voltage amplification section, and the gain of the high voltage amplifier is set to 200 times. Capacitor C2, connected in parallel with resistor R2, determines the bandwidth of the high-voltage amplifier. It is possible to widen the bandwidth by reducing the capacitance of capacitor C2, but the bandwidth cannot be widened indefinitely beyond the performance of the high-voltage amplifier, so if the basic performance is not good, it is not possible to widen the bandwidth simply by reducing the capacitance of capacitor C2. Figure 1-3 shows a distorted output waveform due to the bandwidth being broadened beyond the response performance of the high-voltage amplifier, which can also cause a voltage higher than the MOSFET's withstand voltage to be applied.

[0007] The input signal amplified by operational amplifier U1, which operates on a ±15 power supply, drives photocouplers U101 and U102 via resistors R3 and R4, and the signal is transmitted to the high-voltage amplifier section. Resistors R5 and R6 are provided to allow a small amount of current to flow from the ±15V power supply through these resistors to the inputs of photocouplers U101 and U102 when the input signal is 0V, i.e., when the output of operational amplifier U1 is 0V, thereby ensuring the quiescent current of each MOSFET in the positive and negative output stages and eliminating zero-cross distortion. Diodes D1 and D2 are protection diodes that prevent reverse bias voltage from being applied to the light-emitting diodes at the inputs of photocouplers U101 and U201. Capacitor C1 and resistor R7 connected in series between the output and inverting input of operational amplifier U1 are provided to provide phase compensation for the high voltage amplifier and prevent oscillation.

[0008] The high-voltage n-channel MOSFETs Q102 and Q101, current limiting resistor R141, and photocoupler U101 are connected in series in two stages in the positive output stage of the high-voltage amplifier, and are inserted between the +HVps high-voltage power supply and the output terminal. The high-voltage n-channel MOSFETs Q202 and Q201, current limiting resistor R241, and photocoupler U201 are connected in two stages in series in the negative output stage of the high-voltage amplifier section, and are located between the output terminal and the -HVps high-voltage power supply. In this way, by connecting individual high-voltage mosFETs in multiple stages in series, it is possible to create a high-voltage amplifier with a voltage higher than that of the mosFET. The current limiting resistors R141 and R241 are provided to limit the maximum output current and protect the high-voltage amplifier in the event of an output short circuit accident that causes the load to become 0 Ω.

[0009] The 5MΩ high resistors R102 and R101 connected in series to the positive output stage and the Zener diode Z101 for generating a constant voltage are placed between the +HVps high voltage power supply and the output terminal, and the potential equally divided by these resistors provides the gate potential VQ102-G of the mosFET Q102, and the zener voltage of the zener diode Z101 provides the gate potential of the mosFET Q101. The 5MΩ high resistors R202 and R201 connected in series to the negative output stage and the Zener diode Z201 for generating a constant voltage are placed between the output terminal and the -HVps high voltage power supply, and the potential equally divided by these resistors provides the gate potential VQ202-G of the mosFET Q202, and the zener voltage of the zener diode Z201 provides the gate potential of the mosFET Q201. Capacitors C101 and C201 connected in parallel to the Zener diodes Z101 and Z201, respectively, are capacitors for stabilizing the Zener voltage. Resistors R131 and R231 are used to prevent oscillation, for example, with a resistance of 0 to 1 kΩ, and are inserted between the gates of mosfets Q101 and Q201 and zener diodes Z101 and Z201, respectively. However, since the voltage drop due to these resistors can be ignored, the zener voltage potential can be considered to be the gate potential. [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-97165 (P2019-97165A) [Patent Document 2] Japanese Patent Application Publication No. 2019-220857 (P2019-220857A) Summary of the Invention [Problem to be solved by the invention]

[0011] However, the conventional circuit example shown in FIG. 1-1 has the following problems. First, Figure 1-2 shows the response waveform when a sine wave signal with an amplitude of ±10V and a frequency of 100Hz is input to the high-voltage amplifier in Figure 1-1. Because the resistance values ​​of resistors R102 and R101 are equal, the voltage applied between the drain and source of each of the mosFETs Q102 and Q101 is approximately equal, and if a low-frequency sine wave input of about 100 Hz is applied, the gate waveform VQ102-G of mosFET Q102 will always be a sine wave with an amplitude approximately halfway between the positive high-voltage power supply +HVps and the output waveform, as shown in Figure 1-2, and at this time the voltage distribution between the drain and source of each of the mosFETs Q102 and Q101 will always remain evenly balanced. Because the resistance values ​​of resistors R202 and R201 are equal, the voltage applied between the drain and source of each of the mosFETs Q202 and Q201 is roughly equal, and if a low-frequency sine wave input of about 100 Hz is applied, the gate waveform VQ202-G of mosFET Q202 will always be a sine wave with an amplitude roughly halfway between the negative high-voltage power supply -HVps and the output waveform, as shown in Figure 1-2, and at this time the voltage distribution between the drain and source of each of the mosFETs Q202 and Q201 will always remain evenly balanced.

[0012] Figure 1-3 shows the response waveform when a sine wave signal with an amplitude of ±10V and a frequency of 1kHz is input to the high-voltage amplifier in Figure 1-1. When the frequency of the input signal is increased to 1 kHz, the voltage distribution balance between mosFETs Q102 and Q101 and between mosFETs Q202 and Q201 is greatly disrupted, as shown in Figure 1-3, and the gate waveforms and output waveforms of VQ102-G and VQ202-G are greatly distorted. If an input signal that changes suddenly, such as a high-frequency sine wave or pulse waveform, disrupts the voltage distribution balance of high-voltage mosFETs connected in series, a voltage higher than the allowable voltage will be applied to a specific mosFET, and in the worst case scenario, that mosFET may be destroyed. This is a waveform distortion caused by the fact that the gate input capacitance of the high-voltage mosFETs Q102 and Q202, which is on the order of several hundred pF to several thousand pF, is driven by the high resistance of resistors R102, R101, R202, and R201, which is 5 MΩ, and therefore the gate potentials VQ102-G and VQ202-G of the mosFETs Q102 and Q202 are unable to follow the input signal, partly due to the adverse effects of the Miller effect. Reducing the resistance value from 5 MΩ to 500 kΩ by one order of magnitude improves the response waveform, but does not achieve satisfactory performance. Moreover, the power loss of these resistors increases to several watts, and the physical size of the resistors also increases, making them impractical. The present invention has been devised in view of the above problems and to effectively solve them.

[0013] The object of the present invention is to provide a high-voltage composite mosFET that improves the response performance of a circuit in which high-voltage mosFETs are connected in series in multiple stages in the high-voltage output section of a high-voltage amplifier, and that can efficiently make the high-voltage amplifier faster and broader in bandwidth without increasing power loss, and to provide a high-voltage amplifier in which this is applied to the output stage circuit of the high-voltage amplifier section. [Means for solving the problem]

[0014] The present invention according to claim 1 is A second mosFET (Q51) having a drain, a gate, and a source different from the first mosFET (Q1) is added to the first mosFET (Q1), One end of a resistor (R41) of 0 Ω or more is connected to the source of the first mosFET (Q1), and the other end of the resistor (R41) is connected to the drain of the added second mosFET (Q51), Connect the first terminal of a resistor (R61) with a resistance of 0 Ω or more to the gate of the first mosFET (Q1). A circuit for generating a constant voltage is provided, the first terminal of the constant voltage terminal of which is connected to the second terminal of the resistor (R61), and the second terminal of the constant voltage terminal is connected to the source of a second MOSFET (Q51); By maintaining a constant voltage between the gate of the first MOSFET (Q1) and the source of the second MOSFET (Q51), The gate of the second mosFET (Q51) acts as the gate of the composite mosFET. The source of the second mosFET (Q51) acts as the source of the compound mosFET. The drain of the first mosFET (Q1) acts as the drain of the compound mosFET. The composite mosFET is characterized by being configured to function.

[0015] The present invention according to claim 2 provides the compounded type mosFET according to claim 1. A resistor (R51), a Zener diode (Z51), and a capacitor (C51) are provided as a circuit for generating the constant voltage, a first terminal of the resistor (R51) is connected to the drain of a first mosFET (Q1) or to a power supply or other device, one end of the Zener diode (Z51) and capacitor (C51) connected in parallel to generate a constant voltage with the current flowing through the resistor (R51) is connected to the second terminal of the resistor (R51) and one end of the Zener diode (Z51) and capacitor (C51) connected in parallel are connected to the second terminal of the resistor (R51) and to the second terminal of the resistor (R61), and the other end of the Zener diode (Z51) and capacitor (C51) connected in parallel is connected to the source of a second mosFET (Q51), and the constant voltage circuit is formed by the resistor, Zener diode, and capacitor, which is a composite mosFET.

[0016] The present invention according to claim 3 provides the compounded type mosFET according to claim 2. When connecting the first terminal of the resistor (R51) to a power supply, connect it to a positive high-voltage power supply. When connecting to a device, connect it to the drain of the other mosFET placed on the higher potential side of the mosFET configured in series connection, The anode, which is one end of the Zener diode (Z51), is connected to the source side of the second mosFET (Q51), By using a high-voltage n-channel mosFET as the first mosFET (Q1) and a low-voltage n-channel mosFET as the second mosFET (Q51) that has a low gate input capacitance and an allowable current that is the same as that of the first mosFET (Q1) or larger than the current limited by the resistor (R41), The composite mosFET operates as an n-channel mosFET. The gate input capacitance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second mosFET (Q51) is small, so the Miller effect is suppressed. Maintaining the high breakdown voltage of the first mosFET (Q1), This is a high-voltage composite n-channel mosFET characterized in that the first and second mosFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) below the allowable current. Incidentally, claim 3 relates to FIG. 3-1A.

[0017] The present invention according to claim 4 provides the compounded type mosFET according to claim 2. When connecting the first terminal of the resistor (R51) to a power supply, connect it to a negative high-voltage power supply. When connecting to a device, connect it to the drain of the other mosFET placed on the lower potential side of the mosFET configured in series connection, The cathode, which is one end of the Zener diode (Z51), is connected to the source side of the second mosFET (Q51), By using a high-voltage p-channel mosFET as the first mosFET (Q1) and a low-voltage p-channel mosFET as the second mosFET (Q51) that has a low gate input capacitance and an allowable current that is the same as that of the first mosFET (Q1) or larger than the current limited by the resistor (R41), The composite mosFET operates as a p-channel mosFET. The gate input capacitance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second mosFET (Q51) is small, so the Miller effect is suppressed. Maintaining the high breakdown voltage of the first mosFET (Q1), This is a high-voltage composite p-channel mosFET characterized in that the first and second mosFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) below the allowable current. Incidentally, claim 4 relates to FIG. 3-2A.

[0018] The present invention according to claim 5 is A second mosFET (Q51) having a drain, a gate, and a source different from the first mosFET (Q1) is added to the first mosFET (Q1), One end of a resistor (R41) of 0 Ω or more is connected to the source of the first mosFET (Q1), and the other end of the resistor (R41) is connected to the drain of the added second mosFET (Q51), Connect the first terminal of a resistor (R61) with a resistance of 0 Ω or more to the gate of the first mosFET (Q1). a circuit for generating a constant voltage, a first terminal of the constant voltage end connected to the second terminal of the resistor (R61), a second terminal of the constant voltage end connected to a first terminal of a resistor (R31) of 0 Ω or more, and a second terminal of the resistor (R31) connected to the gate of a second MOSFET (Q51); By keeping a constant voltage between the gate of the first mosFET (Q1) and the gate of the second mosFET (Q51), The first terminal of the resistor (R31) connected to the gate of the second mosFET (Q51) is As a gate for composite mosFET, The source of the second mosFET (Q51) acts as the source of the compound mosFET. The drain of the first mosFET (Q1) acts as the drain of the compound mosFET. The composite mosFET is characterized by being configured to function.

[0019] The present invention according to claim 6 provides the compounded type mosFET according to claim 5. A resistor (R51), a Zener diode (Z51), and a capacitor (C51) are provided as a circuit for generating the constant voltage, and a first terminal of the resistor (R51) is connected to the drain of a first MOSFET (Q1), or to a power supply or other device, and one end of the Zener diode (Z51) and capacitor (C51), which are connected in parallel to generate a constant voltage with the current flowing through the resistor (R51), is connected to the second terminal of the resistor (R51) and to the second terminal of the resistor (R61); The other end of the parallel-connected Zener diode (Z51) and capacitor (C51) is connected to the first terminal of the resistor (R31); The composite mosFET is characterized in that the constant voltage circuit is configured to be formed by a resistor, a Zener diode, and a capacitor.

[0020] The present invention according to claim 7 provides the compounded type mosFET according to claim 6. When connecting the first terminal of the resistor (R51) to a power supply, connect it to a positive high-voltage power supply. When connecting to a device, connect it to the drain of the other mosFET placed on the higher potential side of the mosFET configured in series connection, The anode, which is one end of the Zener diode (Z51), is connected to the first terminal of the resistor (R31), By using a high-voltage n-channel MOSFET as the first MOSFET (Q1) and a low-voltage n-channel MOSFET as the second MOSFET (Q51) that has a low source input impedance and an allowable current that is the same as that of the first MOSFET (Q1) or larger than the current limited by the resistor (R41), The composite mosFET operates as an n-channel mosFET. The source input impedance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second mosFET (Q51) is small, so the Miller effect is suppressed. Maintaining the high breakdown voltage of the first mosFET (Q1), This is a high-voltage composite n-channel mosFET characterized in that the first and second mosFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) below the allowable current. Incidentally, claim 7 relates to FIG. 3-1B.

[0021] The present invention according to claim 8 provides the compounded type mosFET according to claim 6. When connecting the first terminal of the resistor (R51) to a power supply, connect it to a negative high-voltage power supply. When connecting to a device, connect it to the drain of the other mosFET placed on the lower potential side of the mosFET configured in series connection, The cathode of the Zener diode (Z51) is connected to the first terminal of the resistor (R31), By using a high-voltage p-channel MOSFET as the first MOSFET (Q1) and a low-voltage p-channel MOSFET as the second MOSFET (Q51) that has a low source input impedance and an allowable current that is the same as that of the first MOSFET (Q1) or larger than the current limited by the resistor (R41), The composite mosFET operates as a p-channel mosFET. The source input impedance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second mosFET (Q51) is small, so the Miller effect is suppressed. Maintaining the high breakdown voltage of the first mosFET (Q1), This is a high-voltage composite p-channel mosFET characterized in that the first and second mosFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) below the allowable current. Incidentally, claim 8 relates to FIG. 3-2B.

[0022] The present invention according to claim 9 is In a circuit in which the positive output stage circuit of an amplifier is composed of a photocoupler (U101) and two or more N-stage n-channel MOSFETs (Q10i, i = 1 to N), The point with the highest potential of the positive output stage circuit is designated as node Hn, and the point with the lowest potential is designated as node Ln. The drain of the mosFET (Q10N) is connected to the node Hn, the drain of the mosFET (Q10i, i=N-1) is connected to its source, the drain of the mosFET (Q10i, i=N-2) is connected to its source, and so on, with the mosFETs connected in series, and the drain of the last mosFET (Q101) is connected to the source of the mosFET (Q102), N resistors (R10i, i=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R10N) is connected to a node Hn, a second terminal of the resistor (R10i, i=N-1) is connected to a first terminal of the resistor (R10i, i=N-1), and so on, the resistors are connected in series, and the first terminal of the last resistor (R101) is connected to the second terminal of the resistor (R102), and a constant voltage is generated; A second terminal of the resistor (R101) is connected to the positive side of the constant voltage end of the constant voltage circuit, and a negative side of the constant voltage end of the constant voltage circuit is connected to a node Ln, A second terminal of the resistor (R10N) is connected to the gate of the mosFET (Q10N); The second terminal of the resistor (R10i, i=N-1) is connected to the gate of the mosFET (Q10i, i=N-1), and so on, connecting the second terminal of the resistor (R10i) to the gate of the mosFET (Q10i) and finally connecting the second terminal of the resistor (R101) to the gate of the mosFET (Q101). A predetermined bias voltage is applied to the gate of each mosFET (Q10i, i = 1 to N), The source of the mosFET (Q101) is connected to the collector of the photocoupler (U101) via a current limiting resistor of 0 Ω or more, and the emitter is connected to a node Ln. connecting node Hn to a positive high voltage power supply for application to said positive output stage of the amplifier; Node Ln is connected to the output end, The compound n-channel mosFET of claim 7 is applied to the single mosFET (Q101), This is a positive output stage of a high-voltage amplifier characterized in that the compounded n-channel mosFET of claim 3 is applied to each of the single mosFETs (Q10i, i = 2 to N), thereby providing a source current control function that is made faster by the compounded n-channel mosFET. Incidentally, this claim 9 relates to the positive side output stage of the high voltage amplifier in FIG. 2-1 and FIG. 7-1 in which N is 2 and FIG. 6 in which N is 3, to which a compound type n-channel mosFET is applied.

[0023] The present invention according to claim 10 is In a circuit in which the negative output stage circuit of an amplifier is composed of a photocoupler (U201) and two or more N-stage n-channel MOSFETs (Q20j, j=1 to N), The point with the highest potential in the negative-side output stage circuit is designated as node Hn, and the point with the lowest potential is designated as node Ln, The drain of the mosFET (Q20N) is connected to the node Hn, the drain of the mosFET (Q20j, j=N-1) is connected to its source, the drain of the mosFET (Q20j, j=N-2) is connected to its source, and so on, with the mosFETs connected in series, and the drain of the last mosFET (Q201) is connected to the source of the mosFET (Q202), N resistors (R20j, j=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R20N) is connected to a node Hn, a second terminal of the resistor is connected to a first terminal of the resistor (R20j, j=N-1), and so on, the resistors are connected in series, and the first terminal of the last resistor (R201) is connected to the second terminal of the resistor (R202), and a constant voltage is generated; A second terminal of the resistor (R201) is connected to the positive side of the constant voltage end of the constant voltage circuit, and a negative side of the constant voltage end of the constant voltage circuit is connected to a node Ln, A second terminal of the resistor (R20N) is connected to the gate of the mosFET (Q20N); The second terminal of the resistor (R20j, j=N-1) is connected to the gate of the mosFET (Q20j, j=N-1), and so on until the second terminal of the resistor (R20j) is connected to the gate of the mosFET (Q20j), and finally the second terminal of the resistor (R201) is connected to the gate of the mosFET (Q201). A predetermined bias voltage is applied to the gate of each mosFET (Q20j, j=1 to N), The source of the mosFET (Q201) is connected to the collector of the photocoupler (U201) via a current limiting resistor of 0 Ω or more, and the emitter is connected to a node Ln, connecting node Hn to an output for application to said negative output stage of the amplifier; Connect node Ln to the negative high voltage power supply, The compound n-channel mosFET of claim 7 is applied to the single mosFET (Q201), This is a negative output stage of a high-voltage amplifier characterized in that the compounded n-channel mosFET of claim 3 is applied to each of the single mosFETs (Q20j, j = 2 to N), thereby providing a high-speed sink current control function using the compounded n-channel mosFET. Incidentally, claim 10 relates to the negative side output stage of the high voltage amplifier in FIG. 2-1 and FIG. 7-2 in which N is 2 and FIG. 6 in which N is 3, to which a compound type n-channel mosFET is applied.

[0024] The present invention according to claim 11 is In a circuit in which the positive output stage circuit of an amplifier is composed of a photocoupler (U101) and two or more N stages of p-channel MOSFETs (Q10i, i = 1 to N), The point with the highest potential of the positive output stage circuit is defined as node Hp, and the point with the lowest potential is defined as node Lp. The drain of the mosFET (Q10N) is connected to the node Lp, the drain of the mosFET (Q10i, i=N-1) is connected to its source, the drain of the mosFET (Q10i, i=N-2) is connected to its source, and so on, with the mosFETs connected in series, and the drain of the last mosFET (Q101) is connected to the source of the mosFET (Q102), N resistors (R10i, i=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R10N) is connected to a node Lp, a second terminal of the resistor (R10i, i=N-1) is connected to a first terminal of the resistor (R10i, i=N-1), and so on, the resistors are connected in series, and the first terminal of the last resistor (R101) is connected to the second terminal of the resistor (R102), and a constant voltage is generated; a second terminal of the resistor (R101) is connected to the negative side of the constant voltage end of the constant voltage circuit, and a positive side of the constant voltage end of the constant voltage circuit is connected to a node Hp; A second terminal of the resistor (R10N) is connected to the gate of the mosFET (Q10N); The second terminal of the resistor (R10i, i=N-1) is connected to the gate of the mosFET (Q10i, i=N-1), and so on, connecting the second terminal of the resistor (R10i) to the gate of the mosFET (Q10i) and finally connecting the second terminal of the resistor (R101) to the gate of the mosFET (Q101). A predetermined bias voltage is applied to the gate of each mosFET (Q10i, i = 1 to N), The source of the mosFET (Q101) is connected to the emitter of the photocoupler (U101) via a current limiting resistor of 0 Ω or more, and the collector is connected to a node Hp. connecting node Hp to a positive high voltage power supply for application to said positive output stage of the amplifier; Node Lp is connected to the output end, The compound type p-channel mosFET of claim 8 is applied to the single mosFET (Q101), This is a positive output stage of a high-voltage amplifier characterized in that the compounded p-channel mosFET of claim 4 is applied to each of the single mosFETs (Q10i, i = 2 to N), thereby providing a source current control function that is made faster by the compounded p-channel mosFET. Incidentally, this claim 11 relates to the positive output stage of the high voltage amplifier in FIGS. 7-2 and 7-3, in which N is set to 2 and a compound type p-channel mosFET is applied.

[0025] The present invention according to claim 12 is In a circuit in which the negative output stage circuit of an amplifier is composed of a photocoupler (U201) and two or more N stages of p-channel MOSFETs (Q20j, j = 1 to N), The point with the highest potential of the negative-side output stage circuit is defined as node Hp, and the point with the lowest potential is defined as node Lp. The drain of the mosFET (Q20N) is connected to the node Lp, the drain of the mosFET (Q20j, j=N-1) is connected to its source, the drain of the mosFET (Q20j, j=N-2) is connected to its source, and so on, with the mosFETs connected in series, and the drain of the last mosFET (Q201) is connected to the source of the mosFET (Q202), N resistors (R20j, j=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R20N) is connected to a node Lp, a second terminal of the resistor is connected to a first terminal of the resistor (R20j, j=N-1), and so on, the resistors are connected in series, and the first terminal of the last resistor (R201) is connected to the second terminal of the resistor (R202), and a constant voltage is generated; A second terminal of the resistor (R201) is connected to the negative side of the constant voltage end of the constant voltage circuit, and a positive side of the constant voltage end of the constant voltage circuit is connected to a node Hp, A second terminal of the resistor (R20N) is connected to the gate of the mosFET (Q20N); The second terminal of the resistor (R20j, j=N-1) is connected to the gate of the mosFET (Q20j, j=N-1), and so on until the second terminal of the resistor (R20j) is connected to the gate of the mosFET (Q20j), and finally the second terminal of the resistor (R201) is connected to the gate of the mosFET (Q201). A predetermined bias voltage is applied to the gate of each mosFET (Q20j, j=1 to N), The source of the mosFET (Q201) is connected to the emitter of the photocoupler (U201) via a current limiting resistor of 0 Ω or more, and the collector is connected to a node Hp. connecting node Hp to an output for application to the negative output stage of the amplifier; Connect node Lp to the negative high voltage power supply, The compound type p-channel mosFET of claim 8 is applied to the single mosFET (Q201), This is a negative output stage of a high-voltage amplifier characterized in that the compounded p-channel mosFET of claim 4 is applied to each of the single mosFETs (Q20j, j = 2 to N), thereby providing a high-speed sink current control function using the compounded p-channel mosFET. Incidentally, this claim 12 relates to the negative side output stage of the high voltage amplifier part in FIGS. 7-1 and 7-3, in which N is set to 2 and a compound type p-channel mosFET is applied.

[0026] The present invention according to claim 13 is an input stage having a low-voltage amplification section, an output stage having a high-voltage amplification section, and a photocoupler interposed between the input stage and the output stage; the output stage has a positive output stage connected to a positive high voltage power supply for controlling a source current, and a negative output stage connected to a negative high voltage power supply for controlling a sink current; The photocoupler also includes a photocoupler (U101) that controls the positive output stage and a photocoupler (U201) that controls the negative output stage, In a high-voltage amplifier, an input signal is amplified by the low-voltage amplifier, the amplified signal is introduced into the high-voltage amplifier through the photocoupler (U101, U201), and the amplified signal is output from an output terminal, The positive output stage includes two or more N mosFETs (Q10i, i = 1 to N), These mosFETs are connected in series in numerical order (Q10N, . . . , Q102, Q101), and the photocoupler (U101) is connected to drive the source of the mosFET (Q101) via a current limiting resistor of 0 Ω or more, and these series-connected mosFETs (Q10i, i = 1 to N) and the photocoupler (U101) are placed between the positive high-voltage power supply and the output terminal, The negative output stage is provided with N identical mosFETs (Q20j, j=1 to N), These mosFETs are connected in series in numerical order (Q20N, . . . , Q202, Q201), and the photocoupler (U201) is connected so that the source of the mosFET (Q201) is driven via a current limiting resistor of 0 Ω or more, and these series-connected mosFETs (Q20j, j = 1 to N) and the photocoupler (U201) are arranged between the negative high-voltage power supply and the output terminal, N resistors (R10i, i=1 to N) and a circuit for generating a constant voltage or a Zener diode (Z101) are provided on the positive output stage side, and these are connected in series in numerical order (R10N, . . . , R102, R101, Z101), and placed between the positive high-voltage power supply and the output terminal, A circuit is provided which applies a bias voltage of a potential obtained by equally dividing the voltage from the positive high-voltage power supply to the output terminal to the gate of each mosFET (Q10i, i=1 to N) of the positive side output stage, By providing N resistors (R20j, j=1 to N) on the negative output stage side and a circuit for generating a constant voltage or a Zener diode (Z201), connecting these in series in numerical order (R20N, . . . , R202, R201, Z201), and arranging them between the negative high-voltage power supply and the output terminal, a circuit that applies a bias voltage of a potential obtained by equally dividing the voltage from the negative high-voltage power supply to the output terminal to the gate of each mosFET (Q20j, j=1 to N) of the negative-side output stage; This high-voltage amplifier is characterized in that the high-voltage amplifier section is configured to control the source current at the positive output stage and the sink current at the negative output stage.

[0027] The present invention according to claim 14 provides a high-voltage amplifier according to claim 13, The positive output stage of the high-voltage amplifier section is an output stage of claim 9 or claim 11, in which the mosFET (Q10i, i=1 to N) is replaced with a composite mosFET; The negative-side output stage of the high-voltage amplifier section is an output stage of claim 10 or claim 12, in which the mosFET (Q20j, j=1 to N) is replaced with a composite mosFET; This is a high-voltage amplifier characterized by being configured to achieve high speed and wide bandwidth. Incidentally, claim 14 relates to a high-voltage amplifier in which the compounded type mosFET of claims 9 to 12 is applied to claim 13.

[0028] The present invention according to claim 15 is In the high-voltage amplifier according to claim 14, the mosFET (Q15i, i=1 to N) which constitutes a compounded mosFET in combination with the mosFET (Q10i, i=1 to N) and the mosFET (Q25j, j=1 to N) which constitutes a compounded mosFET in combination with the mosFET (Q20j, j=1 to N), The mosFET (Q15i, i = 1 to N) of the positive output stage is configured with an n-channel or p-channel, and the mosFET (Q25j, j = 1 to N) of the negative output stage is configured with an n-channel or p-channel. When the positive output stage and the negative output stage are configured with mosFETs of different channels as shown in Figures 7-1 and 7-2, where i and j are i = 2 to N, and j = i, When the positive output stage and the negative output stage are configured with mosFETs of the same channel as in Figures 2-1, 6, and 7-3, i and j are set to j=N+2-i for i=2 to N, and There are 2·(N-1) sets of resistors and capacitors connected in series with a resistance of 0 Ω or more. For each of the N-1 combinations of mosFETs (Q15i, Q25j) consisting of the mosFET (Q15i) in the positive output stage and the mosFET (Q25j) in the negative output stage, The series-connected resistor and capacitor are connected between the source of the mosFET (Q15i) and the gate of the mosFET (Q25j), and the series-connected resistor and capacitor are connected between the source of the mosFET (Q25j) and the gate of the mosFET (Q15i), This high-voltage amplifier is characterized by its configuration in which a low-impedance source drives a high-impedance gate via a series-connected resistor and capacitor, thereby achieving high speed and wide bandwidth. Incidentally, claim 15 relates to resistors R172, R173, R272, R273 and capacitors C172, C173, C272, C273 in the high-voltage amplifiers of Figures 2-1, 7-1, 7-2, and 7-3 where N is 2, and Figure 6 where N is 3.

[0029] The present invention according to claim 16 is 15. The high voltage amplifier of claim 14, N sets of resistors and capacitors with a resistance of 0 Ω or more connected in series are provided. These are connected in parallel to each of the N resistors (R10i, i = 1 to N) in the positive output stage, and N sets of resistors and capacitors of 0 Ω or more connected in series are further provided, These are connected in parallel to each of the N resistors (R20j, j = 1 to N) in the negative output stage, making this a high-voltage amplifier characterized by being configured to prevent oscillation and provide stable, high-speed response. Incidentally, claim 16 relates to resistors R181 to R183, R281 to R283 and capacitors C161 to C163, C261 to C263 in the high-voltage amplifiers of Figures 2-1, 7-1, 7-2, and 7-3 where N is 2, and Figure 6 where N is 3.

[0030] The present invention according to claim 17 is 16. The high voltage amplifier of claim 15, The resistor and capacitor connected in series according to claim 16 are connected in parallel to each of the resistors (R10i, i = 1 to N) and the resistors (R20j, j = 1 to N) in the output stage, This high-voltage amplifier is characterized by its configuration, which prevents oscillation, operates stably even under no load, and achieves high speed and wide bandwidth. Note that claim 17 is a combination of claim 15 and claim 16, and relates to the high-voltage amplifiers of Figures 2-1, 7-1, 7-2, and 7-3 in which N is 2, and Figure 6 in which N is 3.

[0031] The present invention according to claim 18 is In the high-voltage amplifier according to claim 13, the mosFETs (Q10i, i = 1 to N) and the mosFETs (Q20j, j = 1 to N) When the mosFET (Q10i, i = 1 to N) of the positive output stage configured with an n-channel or p-channel and the mosFET (Q20j, j = 1 to N) of the negative output stage configured with an n-channel or p-channel are configured with mosFETs of different channels, i and j are set to i = 2 to N, and j = i, When the positive output stage and the negative output stage are configured with mosFETs of the same channel as shown in Figure 4-1, i and j are set to i = 2 to N, and j = N + 2 - i, There are 2·(N-1) sets of resistors and capacitors connected in series with a resistance of 0 Ω or more. For each of the N-1 combinations of mosFETs (Q10i, Q20j) consisting of the mosFET (Q10i) in the positive output stage and the mosFET (Q20j) in the negative output stage, The resistor and capacitor connected in series are connected between the source of the mosFET (Q10i) and the gate of the mosFET (Q20j), and the resistor and capacitor connected in series are connected between the source of the mosFET (Q20j) and the gate of the mosFET (Q10i), This high-voltage amplifier is characterized by being configured to achieve high-speed response by having a low-impedance source drive a high-impedance gate through a series-connected resistor and capacitor. Incidentally, this claim 18 relates to the resistors R172, R272 and capacitors C172, C272 in the high-voltage amplifier of FIG. 4-1 in which N is set to 2.

[0032] The present invention according to claim 19 is 14. The high voltage amplifier of claim 13, N sets of resistors and capacitors with a resistance of 0 Ω or more connected in series are provided. These are connected in parallel to each of the N resistors (R10i, i = 1 to N) in the positive output stage, and N sets of resistors and capacitors of 0 Ω or more connected in series are further provided, These are connected in parallel to each of the N resistors (R20j, j = 1 to N) in the negative output stage, preventing oscillation and enabling stable operation even when there is no load, making this a high-voltage amplifier. Incidentally, claim 19 relates to the resistors R181, R182, R281, and R282 and the capacitors C161, C162, C261, and C262 in the high-voltage amplifier of FIG. 4-1 in which N is set to 2.

[0033] The present invention according to claim 20 is 19. The high voltage amplifier of claim 18, The resistor and capacitor connected in series according to claim 19 are connected in parallel to each of the resistors (R10i, i = 1 to N) and the resistors (R20j, j = 1 to N) in the output stage, This high-voltage amplifier is characterized by being configured to prevent oscillation and provide stable, high-speed response. Incidentally, claim 20 is a combination of claim 18 and claim 19, and relates to the high-voltage amplifier of FIG. 4-1 in which N is set to 2. [Effects of the Invention]

[0034] According to the inventions of claims 1 to 4, Conventional single high voltage MOSFET Large gate input capacitance, The Miller effect, which is proportional to the voltage change between the drain and source, is significant. No current limit protection High-voltage composite mosFET solves these problems. By reducing the gate input capacitance to, for example, 1 / 100, The Miller effect is suppressed by suppressing the influence of voltage changes between the drain and source. For example, it can be reduced to about 1 / 1000, Maintaining the withstand voltage of a single high-voltage mosFET, It has a function to limit the current to below the allowable current, protecting the element. The following effects can be obtained. Although it is a mosFET current limiter, there is no delay between the detection of the limit current and the function taking effect, so the current is always limited to below the value determined by the current limiting resistor, ensuring reliable protection of the mosFET. Claim 3 relates to the high-voltage composite n-channel MOSFET shown in FIG. 3-1A. Claim 4 relates to the high-voltage composite p-channel mosFET of FIG. 3-2A.

[0035] According to the inventions of claims 5 to 8, Conventional single high voltage MOSFET High source input impedance, The Miller effect, which is proportional to the voltage change between the drain and source, is significant. No current limit protection High-voltage composite mosFET solves these problems. Reduce the source input impedance to, for example, 1 / 100, The Miller effect is suppressed by suppressing the influence of voltage changes between the drain and source. For example, it can be reduced to about 1 / 1000, Maintaining the withstand voltage of a single high-voltage mosFET, It has a function to limit the current to below the allowable current, protecting the element. The following effects can be obtained. Although it is a mosFET current limiter, there is no delay between the detection of the limit current and the function taking effect, so the current is always limited to below the value determined by the current limiting resistor, ensuring reliable protection of the mosFET. Claim 7 relates to the high-voltage composite n-channel mosFET shown in FIG. 3-1B. Claim 8 relates to the high-voltage composite p-channel mosFET of FIG. 3-2B.

[0036] According to the inventions of claims 9 to 12, This has the effect of enabling the positive and negative output stages of the high voltage amplifier to respond at high speed. The composite mosFETs according to claims 1 to 8 are applied to the positive and negative output stages, Claim 9 relates to a positive output stage circuit using an n-channel mosFET, Claim 10 relates to a negative side output stage circuit using an n-channel mosFET, Claim 11 relates to a positive output stage circuit using a p-channel mosFET, Claim 12 relates to a negative side output stage circuit using a p-channel mosFET.

[0037] According to the inventions of claims 13 to 17, The compounded n-channel mosfets of claim 9 or the compounded p-channel mosfets of claim 11 are applied to the positive output stage of the high voltage amplifier, By applying the compounded n-channel mosfets of claim 10 or the compounded p-channel mosfets of claim 12 to the negative output stage of the high voltage amplifier, These positive and negative output stages can be selected and combined as desired, resulting in the effect of speeding up and widening the bandwidth of the high-voltage amplifier response using high-voltage composite mosFETs. While the conventional circuit example of Fig. 1-1 could only realize a high-voltage amplifier bandwidth up to about several hundred Hz, the high-voltage amplifier circuit of the present invention of Fig. 2-1 to which claims 13 to 17 are applied provides a ±2 kV output response waveform to a sine wave input of ±10 V amplitude and 10 kHz frequency, as shown in Fig. 2-2, which is a sine wave output waveform without oscillation or distortion, thereby achieving the effect of maintaining a stable amplification function as a high-voltage amplifier even with a sine wave of 10 kHz frequency. Furthermore, as shown in Fig. 2-3, the frequency characteristics of the output of the high-voltage amplifier Fig. 2-1 are wider than the bandwidth of conventional high-voltage amplifiers by more than two orders of magnitude, achieving the effect of enabling the bandwidth of the high-voltage amplifier to be realized up to, for example, about 100 kHz. Moreover, it is important to suppress the power loss that accompanies the broadband, and this also has the effect of helping to reduce the size of components.

[0038] According to the inventions of claims 18 to 20, Even a high-voltage amplifier using a single high-voltage mosFET can achieve the effect of speeding up response and widening bandwidth. In the conventional circuit example of Figure 1-1, the bandwidth of the high-voltage amplifier could only be realized up to several hundred Hz, but in the circuit of Figure 4-1, which applies claims 18 to 20 to Figure 1-1, a sine wave output waveform without oscillation or distortion is obtained in response to a sine wave input of ±10V amplitude and 1kHz frequency, as shown in Figure 4-2, and the effect of maintaining stable amplification function as a high-voltage amplifier is obtained even with a sine wave of 1kHz frequency. [Brief explanation of the drawings]

[0039] [Figure 1-1] FIG. 1 is a diagram illustrating a basic circuit example of a high-voltage amplifier. [Figure 1-2] This figure shows the response waveform when a 100 Hz, ±10 V sine wave is input (±2 kV output) to the high-voltage amplifier in Figure 1-1. [Figure 1-3] This figure shows the response waveform when a 1 kHz, ±10 V sine wave is input (±2 kV output) to the high-voltage amplifier in Figure 1-1. [Figure 2-1] 1 is a diagram showing a circuit of a high-voltage amplifier according to one embodiment of the present invention; [Figure 2-2] This figure shows the response waveform when a 10 kHz, ±10 V sine wave is input (±2 kV output) to the high-voltage amplifier in Figure 2-1. [Figure 2-3] 2-1 is a diagram showing the frequency characteristics of the output of the high-voltage amplifier FIG. [Figure 3-1A] FIG. 1 is a diagram showing an example of a circuit of a high-voltage composite n-channel mosFET in which the gate input capacitance of a single high-voltage n-channel mosFET is reduced equivalently and the Miller effect is eliminated. [Figure 3-1B] FIG. 1 is a diagram showing an example of a circuit of a high-voltage composite n-channel mosFET in which the source input impedance of a single high-voltage n-channel mosFET is equivalently reduced and the Miller effect is eliminated. [Figure 3-2A]FIG. 1 is a diagram showing an example of a circuit of a high-voltage composite p-channel mosFET in which the gate input capacitance of a single high-voltage p-channel mosFET is reduced equivalently and the Miller effect is eliminated. [Figure 3-2B] FIG. 1 is a diagram showing an example of a circuit of a high-voltage composite p-channel mosFET in which the source input impedance of a single high-voltage p-channel mosFET is equivalently reduced and the Miller effect is eliminated. [Figure 4-1] This is a diagram showing a high-voltage amplifier circuit in which the source of one of the single high-voltage MOSFETs Q102 and Q202 in Figure 1-1 drives the gate of the other via capacitors C172 and C272. [Figure 4-2] This figure shows the response waveform when a 1 kHz, ±10 V sine wave is input (±2 kV output) in the high-voltage amplifier shown in Figure 4-1. [Figure 5-1] This is a circuit diagram for explaining oscillation in a circuit in which the capacitors C162, C161, C262, and C261 and the resistors R182, R181, R282, and R281 for preventing oscillation in FIG. 2-1 have been removed. [Figure 5-2] This figure shows the response waveform when a 1 kHz, ±10 V sine wave is input (±2 kV output) to the high-voltage amplifier in Figure 5-1. [Figure 6] This is a high-voltage amplifier circuit that outputs ±3kV, configured with high-voltage n-channel mosFETs Q103, Q102, Q101, Q203, Q202, and Q201 connected in three stages in series for both the positive and negative output stages. This is a circuit diagram in which compound n-channel mosFETs are used for these high-voltage mosFETs. [Figure 7-1] This is a ±2kV output high-voltage amplifier circuit consisting of high-voltage mosFETs Q102, Q101, Q202, and Q201 connected in two stages in series for both the positive and negative output stages. The high-voltage mosFETs Q102 and Q101 in the positive output stage are composite n-channel mosFETs, and the high-voltage mosFETs Q202 and Q201 in the negative output stage are composite p-channel mosFETs. [Figure 7-2]This is a ±2kV output high-voltage amplifier circuit consisting of high-voltage mosFETs Q102, Q101, Q202, and Q201 connected in two stages in series for both the positive and negative output stages. The high-voltage mosFETs Q102 and Q101 in the positive output stage are composite p-channel mosFETs, and the high-voltage mosFETs Q202 and Q201 in the negative output stage are composite n-channel mosFETs. [Figure 7-3] This is a circuit diagram of a high-voltage amplifier with a ±2 kV output, consisting of high-voltage mosFETs Q102, Q101, Q202, and Q201 connected in two stages in series in both the positive and negative output stages, and shows a circuit in which the high-voltage mosFETs Q102, Q101, Q202, and Q201 in the positive and negative output stages are all composed of composite p-channel mosFETs. DETAILED DESCRIPTION OF THE INVENTION

[0040] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the circuit elements described in the conventional circuit diagram shown in FIG. 1-1 will be given the same reference numerals and their description will be omitted. First, Figure 2-1 is a diagram showing a composite mosFET according to the present invention and a circuit of a high-voltage amplifier in which this is applied to an output stage circuit, Figure 2-2 is a diagram showing the response waveform of Figure 2-1 when a 10 kHz, ±10 V sine wave is input (±2 kV output), and Figure 2-3 is a diagram showing the frequency characteristics of the output of Figure 2-1. Also, Figure 3-1A is a diagram showing an example of a circuit of a high-voltage composite n-channel mosFET in which the gate input capacitance of a single high-voltage n-channel mosFET is equivalently reduced and the Miller effect is eliminated. FIG. 3-1B is a diagram showing an example of a circuit of a high-voltage composite n-channel mosFET in which the source input impedance of a single high-voltage n-channel mosFET is equivalently reduced and the Miller effect is eliminated. Incidentally, FIG. 2-1 corresponds to claim 17. In Fig. 2-1, the upper half shows a positive-side output stage circuit A1, and the lower half shows a negative-side output stage circuit A2. Also, symbol B1 is the compounded mosFET of Fig. 3-1A, and symbol B2 is the compounded mosFET of Fig. 3-1B. High-voltage amplifier of the present invention Figures 2-1 and 7-1 to 7-3 show a high-voltage amplifier with an amplifier gain of 200 times and an output of ±2 kV, which solves the problems described above. Similarly, Figure 6 shows a high-voltage amplifier with an amplifier gain of 300 times and an output of ±3 kV, which solves the problems described above.

[0041] FIG. 2-1 showing a high-voltage amplifier according to one embodiment of the present invention replaces the single high-voltage n-channel mosFETs Q102 and Q202 in FIG. 1-1 with the compound n-channel mosFETs shown in FIG. 3-1A. However, in FIG. 2-1, the current limiting resistor R41 in FIG. 3-1A is omitted and set to 0 Ω. FIG. 3-1A corresponds to claim 3. The drains of the low-voltage n-channel mosFETs Q152 and Q252 are connected to the sources of the high-voltage mosFETs Q102 and Q202, respectively. The mosFETs Q152 and Q252 are low-voltage n-channel mosFETs of, for example, about 20V to 50V, and are selected to have small gate input capacitance. Even if the low-voltage mosFETs Q152 and Q252 have the same allowable current as the high-voltage mosFETs Q102 and Q202, the gate input capacitance of the mosFETs Q152 and Q252 can be reduced to, for example, about 1 / 100 of that of the mosFETs Q102 and Q202. Between the gate of mosFET Q102 and the source of mosFET Q152, and between the gate of mosFET Q202 and the source of mosFET Q252, a constant voltage of, for example, 10V is maintained, which is generated by Zener diodes Z152, Z252 and capacitors C152, C252 due to the current flowing through resistors R152 and R252, and mosFETs Q152 and Q252 operate at a low voltage of just a few volts between drain and source, and voltage changes between drain and gate are extremely small, so there is almost no adverse effect from the Miller effect that was a problem with mosFETs Q102 and Q202 in Figure 1-1, and there is almost no degradation in response performance even though resistors R102, R101, R202, and R201 have a high resistance value of 5MΩ. That is, the compounded n-channel mosFET shown in FIG. 3-1A can reduce the gate input capacitance equivalent to that of a single n-channel mosFET and can eliminate the Miller effect. The gates of mosFETs Q102 and Q202 are maintained at low impedance, and their sources are driven by mosFETs Q152 and Q252, so the high-voltage mosFETs Q102 and Q202 are able to respond quickly even when there is a large change in voltage between the drain and source. Resistors R162 and R262 are used to prevent oscillation, for example, with a resistance of 0 to 1 kΩ, and are inserted between the gates of mosFETs Q102 and Q202 and Zener diodes Z152 and Z252, respectively. However, since the voltage drop due to these resistors can be ignored, the Zener voltage potential can be considered to be the gate potential. There are other ways to maintain a constant voltage between the gate of mosFET Q102 and the source of mosFET Q152, and between the gate of mosFET Q202 and the source of mosFET Q252, such as using an isolated DC / DC power supply. Unlike the method of driving the gate of a high-voltage mosFET with a push-pull circuit consisting of a low-voltage p-channel mosFET and an n-channel mosFET, there is no state in which both are inactive at the moment the operation switches, making stable operation possible.

[0042] Figure 2-2 shows the response waveform of the ±2kV output to a sine wave input of amplitude ±10V and frequency 10kHz in the circuit of Figure 2-1. A distortion-free sine wave output waveform is obtained, and the amplifier function as a high-voltage amplifier is maintained even with a sine wave of frequency 10kHz. The gate potential waveform VQ152-G of mosFET Q152, which has voltage division control equal between the positive high-voltage power supply and the output terminal by high resistors R102 and R101, and the gate potential waveform VQ252-G of mosFET Q252, which has voltage division control equal between the output terminal and the negative high-voltage power supply by high resistors R202 and R201, are sine waves without distortion, and the sources of the high-voltage mosFETs Q102 and Q202 are driven at high speed by the drains of these low-voltage mosFETs Q152 and Q252, making it possible to prevent the voltage distribution balance of the high-voltage mosFETs Q102, Q101 and Q202, Q201 from being disrupted. Figure 2-3 shows the frequency characteristics of the output of the high-voltage amplifier (Figure 2-1), and as a high-voltage amplifier, a bandwidth of 100 kHz is ensured. That is, the bandwidth can be increased by two orders of magnitude or more compared to conventional circuits, and the bandwidth of the high-voltage amplifier can be increased to, for example, about 100 kHz. Moreover, it is possible to suppress the increase in power loss that accompanies the broadening of the bandwidth.

[0043] Furthermore, in FIG. 2-1, the single high-voltage n-channel mosFETs Q101 and Q201 in FIG. 1-1 are replaced with the compound n-channel mosFETs shown in FIG. 3-1B. In other words, it is a ±2kV output high-voltage amplifier (amplifier gain is 200 times) that uses high-voltage composite n-channel mosFETs for the mosFETs Q102, Q101, Q202, and Q201 in Figure 1-1. Incidentally, FIG. 3-1B corresponds to claim 7. The drains of the low-voltage n-channel MOSFETs Q151 and Q251 are connected to the sources of the high-voltage MOSFETs Q101 and Q201 via current-limiting resistors R141 and R241, respectively. The MOSFETs Q151 and Q251 are low-voltage n-channel MOSFETs, typically 20V to 50V, and are selected for their low source input impedance. Even if the low-voltage MOSFETs Q151 and Q251 have the same allowable current as the high-voltage MOSFETs Q101 and Q201, their source input impedance can be reduced to, for example, 1 / 100 of that of the MOSFETs Q101 and Q201. This is extremely important for maximizing the response performance of the photocouplers U101 and U201 that drive the sources of the MOSFETs Q151 and Q251. That is, the compounded n-channel mosFET shown in FIG. 3-1B can reduce the source input impedance of a single n-channel mosFET equivalently and eliminate the Miller effect. In Figure 1-1, current-limiting resistors R141 and R241 are inserted between photocoupler U101 and mosFET Q101, and between photocoupler U201 and mosFET Q201 to protect the circuit, but in Figure 2-1, these current-limiting resistors can be moved between mosFET Q101 and mosFET Q151, and between mosFET Q201 and mosFET Q251, allowing direct connections between photocoupler U101 and mosFET Q151, and between photocoupler U201 and mosFET Q251, further improving the response performance of the photocouplers. Between the gate of mosFET Q101 and the gate of mosFET Q151, and between the gate of mosFET Q201 and the gate of mosFET Q251, a constant voltage of, for example, 10 V is maintained which is generated by Zener diodes Z151, Z251 and capacitors C151, C251 due to the current flowing through resistors R151, R251, and the sources of mosFET Q101, Q201 are driven by mosFET Q151, Q251, so the high-voltage mosFETs Q101, Q201 are able to respond quickly even when there is a large change in voltage between their drains and sources. Resistors R161 and R261 are used to prevent oscillation, for example, with a resistance of 0 to 1 kΩ, and are inserted between the gates of mosFETs Q101 and Q201 and Zener diodes Z151 and Z251, respectively. However, since the voltage drop due to these resistors can be ignored, the Zener voltage potential can be considered to be the gate potential. It should be noted that other methods, such as using an isolated DC / DC power supply, can also be used to maintain a constant voltage between the gates of mosFET Q101 and Q151, and between the gates of mosFET Q201 and Q251.

[0044] At the positive and negative output stages of the high-voltage amplifier If the single high-voltage MOSFET configured as in Figure 1-1 is an n-channel, it is replaced with the composite n-channel MOSFET shown in Figures 3-1A and 3-1B as in Figure 2-1. When the individual high-voltage mosFETs that make up the component are p-channel, the use of the composite p-channel mosFETs shown in Figures 3-2A and 3-2B as shown in Figures 7-1 to 7-3 can improve the performance of the output stage in exactly the same way as when using n-channel mosFETs. The composite p-channel mosFET in Figure 3-2A has a structure corresponding to the composite n-channel mosFET in Figure 3-1A, and the composite p-channel mosFET in Figure 3-2B has a structure corresponding to the composite n-channel mosFET in Figure 3-1B. The composite mosFET in Figure 3-2A can reduce the gate input capacitance equivalent to that of a single mosFET and eliminate the Miller effect. FIG. 3-2A corresponds to claim 4. The composite mosFET in Figure 3-2B can reduce the source input impedance of a single mosFET equivalently and eliminate the Miller effect. FIG. 3-2B corresponds to claim 8.

[0045] In the high-voltage amplifier circuit of one embodiment of the present invention shown in FIG. 2-1, even if the output voltage changes in response to the input voltage in the low-frequency range, the potential difference between the source of mosFET Q152 and the gate of mosFET Q252 remains unchanged and can always be maintained at a nearly constant value due to the properties of the circuit. Therefore, focusing on this point, in order to maintain the same state even when the frequency increases, the low impedance source of MOSFET Q152 drives the high impedance gate of MOSFET Q252 via the protective resistor R272 and capacitor C272 connected in series. Similarly, if the high-voltage amplifier in Figure 2-1 is in the low-frequency range, even if the output voltage changes according to the input voltage, the potential difference between the source of mosFET Q252 and the gate of mosFET Q152 will not change and can always be maintained at a nearly constant value due to the properties of the circuit. Therefore, focusing on this point, in order to maintain the same state even when the frequency increases, the low impedance source of MOSFET Q252 drives the high impedance gate of MOSFET Q152 via the protective resistor R172 and capacitor C172 connected in series. These capacitors C172 and C272 function effectively if they are around 1000pF, and because the high resistance of 5MΩ of resistors R102, R101, R202, and R201 in the high frequency range can significantly reduce the current driving the gates of mosfets Q152 and Q252, it is possible to use even larger resistance values, thereby reducing power loss due to these resistors. Furthermore, this technique of driving the gate with a capacitor can also be applied to a single mosFET. In the case of Figure 1-1, this can be achieved by combining mosFETs Q102 and Q202 and configuring a circuit so that the source of one drives the gate of the other via a capacitor. Figure 4-1 shows the single high-voltage MOSFETs Q102 and Q202 of Figure 1-1, with the source of one driving the gate of the other via series-connected resistor R172 and capacitor C172, and resistor R272 and capacitor C272. Figure 4-2 shows the response waveform of the ±2kV output to a sine wave input of amplitude ±10V and frequency 1kHz in the circuit of Figure 4-1. A distortion-free sine wave output waveform is obtained, and the amplifier can maintain its amplification function as a high-voltage amplifier even with a sine wave frequency of 1kHz.

[0046] Also, returning to FIG. 2-1, the high voltage amplifier of FIG. 2-1 according to one embodiment of the present invention A series-connected capacitor C162 and protective resistor R182 are connected in parallel to a high resistance R102, a series-connected capacitor C161 and protective resistor R181 are connected in parallel to a high resistance R101, a series-connected capacitor C262 and protective resistor R282 are connected in parallel to a high resistance R202, and a series-connected capacitor C261 and protective resistor R281 are connected in parallel to a high resistance R201. These capacitors are used to prevent oscillation and have a small capacitance of, for example, about several pF. If the capacitors C162, C161, C262, and C261 and the resistors R182, R181, R282, and R281 are removed from Figure 2-1 as shown in Figure 5-1, the response waveform will oscillate as shown in Figure 5-2. The amplitude of this oscillation is larger for the gate waveform VQ152-G of mosFET Q152 and the gate waveform VQ252-G of mosFET Q252 than for the output waveform, so it is thought to be a local oscillation around mosFETs Q152 and Q252. The capacitors C162, C161, C262, and C261 in Figure 2-1 not only serve to prevent this local oscillation, but also to suppress an increase in the amount of feedback when there is no load in the negative feedback loop path to the operational amplifier U1 that makes up the high-voltage amplifier, thereby preventing the amplifier output from oscillating. Therefore, similarly, by connecting a series-connected resistor and capacitor in parallel to the high resistors R102, R101, R202, and R201 in the circuit in Figure 1-1, it is possible to prevent oscillation when there is no load. Furthermore, since capacitors C162 and C161 are connected in series, and capacitors C262 and C261 are connected in series to the output terminals, the voltage applied to these capacitors is divided into two, so the output capacitive load can be reduced by half.

[0047] Incidentally, Figure 2-1 shows an example of a high-voltage amplifier circuit in which both the positive and negative output stages are made up of high-voltage composite n-channel mosFETs connected in two stages in series between the high-voltage power supply and the output terminal. However, as another aspect of the present invention, an even higher voltage output can be achieved by increasing the number of stages of composite mosFETs connected in series, as shown in Figure 6. FIG. 6 relates to claim 17. Figure 6 shows an example of a high-voltage amplifier circuit using high-voltage composite n-channel mosFETs connected in three stages in series between the high-voltage power supply and the output terminals for both the positive and negative output stages, with an amplifier gain of 300 and an output of ±3 kV. In other words, this is a high-voltage amplifier circuit configured with high-voltage n-channel mosFETs Q103, Q102, Q101, Q203, Q202, and Q201 connected in three stages in series for both the positive and negative output stages, and with a high output voltage of ±3 kV. In this circuit example, the output is ±3 kV, but since there is no limit to the number of series-connected stages, it is possible to increase the number of series-connected stages to produce an even higher voltage output.

[0048] Furthermore, FIG. 7-1 showing a high voltage amplifier according to another embodiment of the present invention is In the high voltage amplifier The positive output stage between the positive high voltage power supply and the output terminal is a series connection of high voltage n-channel mosFETs Q102 and Q101. The negative output stage between the negative high-voltage power supply and the output terminal is composed of two high-voltage p-channel MOSFETs Q202 and Q201 connected in series. The n-channel mosFET Q102 has the high-voltage composite n-channel mosFET structure shown in Figure 3-1A. The n-channel mosFET Q101 has the high-voltage composite n-channel mosFET structure shown in Figure 3-1B. The p-channel mosFET Q202 has the high-voltage composite p-channel mosFET structure shown in Figure 3-2A. The p-channel mosFET Q201 has a high-voltage composite p-channel mosFET structure as shown in Figure 3-2B. This is what was done. That is, the positive and negative output stages are both connected in series in two stages, and the high-voltage MOSFETs Q102, Q101, Q202, and Q201 form a ±2kV output high-voltage amplifier circuit. The high-voltage MOSFETs Q102 and Q101 in the positive output stage are compound n-channel MOSFETs. The high voltage MOSFETs Q202 and Q201 in the negative output stage are compound p-channel MOSFETs. The constructed circuit is shown below. Furthermore, since there is no limit to the number of stages that can be connected in series, it is possible to increase the number of stages that can be connected in series and replace the increased high-voltage mosFETs with composite mosFETs of the same channel, thereby achieving an even higher voltage output. FIG. 7-1 also relates to claim 17.

[0049] Furthermore, FIG. 7-2 showing a high voltage amplifier according to another embodiment of the present invention is In the high voltage amplifier The positive output stage between the positive high voltage power supply and the output terminal is a series connection of high voltage p-channel MOSFETs Q102 and Q101. The negative output stage between the negative high-voltage power supply and the output terminal is composed of two high-voltage n-channel mosFETs Q202 and Q201 connected in series. The p-channel mosFET Q102 has the high-voltage composite p-channel mosFET structure shown in Figure 3-2A. The p-channel mosFET Q101 has the high-voltage composite p-channel mosFET structure shown in Figure 3-2B. The n-channel mosFET Q202 has the high-voltage composite n-channel mosFET structure shown in Figure 3-1A. The n-channel mosFET Q201 has a high-voltage composite n-channel mosFET structure as shown in Figure 3-1B. This is what was done. That is, the positive and negative output stages are both connected in series in two stages, and the high-voltage MOSFETs Q102, Q101, Q202, and Q201 form a ±2kV output high-voltage amplifier circuit. The high-voltage MOSFETs Q102 and Q101 in the positive output stage are compound p-channel MOSFETs. The high-voltage MOSFETs Q202 and Q201 in the negative output stage are compound n-channel MOSFETs. The constructed circuit is shown below. Furthermore, since there is no limit to the number of stages that can be connected in series, it is possible to increase the number of stages that can be connected in series and replace the increased high-voltage mosFETs with composite mosFETs of the same channel, thereby achieving an even higher voltage output. FIG. 7-2 also relates to claim 17.

[0050] Furthermore, FIG. 7-3 showing a high voltage amplifier according to another embodiment of the present invention is In the high voltage amplifier The positive output stage between the positive high voltage power supply and the output terminal is a series connection of high voltage p-channel MOSFETs Q102 and Q101. The negative output stage between the negative high-voltage power supply and the output terminal is composed of two high-voltage p-channel MOSFETs Q202 and Q201 connected in series. The p-channel mosFETs Q102 and Q202 have the high-voltage composite p-channel mosFET structure shown in Figure 3-2A. The p-channel mosFETs Q101 and Q201 have the high-voltage composite p-channel mosFET structure shown in Figure 3-2B. That is, the positive and negative output stages are both connected in series in two stages, and the high-voltage MOSFETs Q102, Q101, Q202, and Q201 form a ±2kV output high-voltage amplifier circuit. This is a diagram showing a circuit in which the high-voltage mosFETs Q102, Q101, Q202, and Q201 in the positive and negative output stages are all configured as compound p-channel mosFETs. FIG. 7-3 also relates to claim 17. In each of the above embodiments, there is no limit to the number of series-connected stages, so it is possible to increase the number of series-connected stages and replace the increased high-voltage mosFETs with composite mosFETs of the same channel to achieve even higher voltage output. Furthermore, the reference numerals given to the components in the claims are merely for the purpose of facilitating understanding of the present invention and do not limit the configuration in any way.

[0051] In the case of a high-voltage amplifier with a unipolar output, such as an output voltage range of 0V to +2kV or -2kV to 0V, a high-voltage power supply is provided only on the output stage side of the high-voltage amplification section of that output polarity, and a low-voltage power supply is used instead of the high-voltage power supply on the output stage side of the other polarity, making it possible to realize a unipolar high-voltage amplifier with the same circuit configuration as a high-voltage amplifier with bipolar output. In other words, it is not necessary to use the same positive and negative high-voltage power supplies for the output stage of the high-voltage amplifier, and the low-voltage power supply used in the low-voltage amplifier may also be used for the high-voltage amplifier. Furthermore, for example, if the circuit capable of outputting -2 kV to +2 kV in FIG. 2-1 is applied to a high-voltage amplifier with a unipolar output, the resulting high-voltage amplifier can output a maximum of 0 V to +4 kV, or a maximum of -4 kV to 0 V. [Explanation of symbols]

[0052] Q1 High voltage mosFET Q51 Low gate input capacitance or low source input impedance, low voltage MOSFET Q1 and Q51 have similar drain current capacitance Z51 Zener diode for constant voltage generation R51 high resistance R31, R41, R61 resistors, including 0Ω C51 Capacitor, for voltage stabilization D Drain of compound type mosFET S Compound type MOSFET source Gate of compound type mosFET A1 High voltage amplifier positive output stage circuit A2 Negative output stage circuit of high voltage amplifier B1 Composite mosFET B2 Composite mosFET R1~R7 resistance C1~C2 capacitors D1~D2 diodes U1 Operational Amplifier +15V +15V low voltage positive power supply -15V -15V low voltage negative power supply U101, U201 photocouplers Q101~Q103, Q201~Q203 High voltage mosFET Z101, Z201 Zener diodes for constant voltage generation R101~R103, R201~R203 High resistance C101, C201 Capacitors, for voltage stabilization Q151, Q251 Low source input impedance, low voltage MOSFET Q152, Q153, Q252, Q253 Low gate input capacitance, low voltage mosFET Z151 to Z153, Z251 to Z253 Zener diodes for constant voltage generation R131, R141, R231, R241 Resistors, for protection, including 0 Ω R151~R153, R251~R253 High resistance R161 to R163, R172, R173, R181 to R183 Resistors, for protection, including 0 Ω R261 to R263, R272, R273, R281 to R283 Resistors, for protection, including 0Ω C151 to C153, C251 to C253 Capacitors, for voltage stabilization C161 to C163, C261 to C263 Capacitors, for preventing oscillation C172, C173, C272, C273 capacitors for gate drive +2100V +2100V high voltage positive power supply -2100V -2100V high voltage negative power supply +3100V +3100V high voltage positive power supply -3100V -3100V high voltage negative power supply +HVps Positive high voltage power supply -HVps Negative High Voltage Power Supply VQ102-G mosFET Q102 gate potential VQ202-G mosFET Q202 gate potential VQ152-G mosFET Q152 gate potential VQ252-G mosFET Q252 gate potential

Claims

1. A second mosFET (Q51) having a drain, a gate, and a source different from that of the first mosFET (Q1) is added to the first mosFET (Q1) having a drain, a gate, and a source; One end of a resistor (R41) of 0 Ω or more is connected to the source of the first mosFET (Q1), and the other end of the resistor (R41) is connected to the drain of an added second mosFET (Q51), A first terminal of a resistor (R61) having a resistance of 0 Ω or more is connected to the gate of the first MOS FET (Q1); a circuit for generating a constant voltage, a first terminal of the constant voltage end of which is connected to the second terminal of the resistor (R61), and a second terminal of which is connected to the source of a second MOS FET (Q51); The gate of the second mosFET (Q51) serves as the gate of the compounded mosFET, The source of the second MOSFET (Q51) serves as the source of the compounded MOSFET. The drain of the first mosFET (Q1) is the drain of the compounded mosFET. A compounded MOSFET characterized by being configured to function.

2. In the compounded MOSFET according to claim 1, A resistor (R51), a Zener diode (Z51), and a capacitor (C51) are provided as a circuit for generating the constant voltage, a first terminal of the resistor (R51) is connected to the drain of a first mosFET (Q1) or to a power supply or other device, one end of the Zener diode (Z51) and the capacitor (C51) which are connected in parallel to generate a constant voltage with a current flowing through the resistor (R51) is connected to the second terminal of the resistor (R51) and to the second terminal of the resistor (R61), and the other end of the Zener diode (Z51) and the capacitor (C51) connected in parallel is connected to the source of a second mosFET (Q51), A compounded type MOSFET, characterized in that the constant voltage circuit is configured to be formed by a resistor, a Zener diode, and a capacitor.

3. In the compounded MOSFET according to claim 2, The first terminal of the resistor (R51) is connected to the positive power supply when connected to the power supply, or to the drain of another MOSFET located on the higher potential side when connected to the device; The anode, which is one end of the Zener diode (Z51), is connected to the source side of the second mosFET (Q51), By applying a high-voltage n-channel mosFET to the first mosFET (Q1) and a low-voltage n-channel mosFET to the second mosFET (Q51) that has a low gate input capacitance and an allowable current that is the same as that of the first mosFET (Q1) or larger than the current limited by the resistor (R41), In this case, the compounded MOSFET operates as an n-channel MOSFET. The gate input capacitance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second MOSFET (Q51) is small, so the Miller effect is suppressed. Maintaining a high breakdown voltage of the first mosFET (Q1), A high-voltage composite n-channel MOSFET characterized in that the first and second MOSFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) to below the allowable current.

4. In the compounded MOSFET according to claim 2, The first terminal of the resistor (R51) is connected to a negative power supply when connected to a power supply, or to the drain of another MOSFET arranged on the lower potential side when connected to a device; The cathode, which is one end of the Zener diode (Z51), is connected to the source side of the second MOS FET (Q51), By applying a high-voltage p-channel mosFET to the first mosFET (Q1) and a low-voltage p-channel mosFET to the second mosFET (Q51) that has a low gate input capacitance and an allowable current that is the same as that of the first mosFET (Q1) or larger than the current limited by the resistor (R41), In this case, the compounded MOSFET operates as a p-channel MOSFET. The gate input capacitance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second MOSFET (Q51) is small, so the Miller effect is suppressed. Maintaining a high breakdown voltage of the first mosFET (Q1), A high-voltage composite p-channel MOSFET characterized in that the first and second MOSFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) to below the allowable current.

5. A second mosFET (Q51) having a drain, a gate, and a source different from that of the first mosFET (Q1) is added to the first mosFET (Q1) having a drain, a gate, and a source; One end of a resistor (R41) of 0 Ω or more is connected to the source of the first mosFET (Q1), and the other end of the resistor (R41) is connected to the drain of an added second mosFET (Q51), A first terminal of a resistor (R61) having a resistance of 0 Ω or more is connected to the gate of the first MOS FET (Q1), a circuit for generating a constant voltage, a first terminal of the constant voltage end of which is connected to the second terminal of the resistor (R61), a second terminal of which is connected to a first terminal of a resistor (R31) of 0 Ω or more, and a second terminal of which is connected to the gate of a second MOS FET (Q51); The first terminal of the resistor (R31) connected to the gate of the second mosFET (Q51) As the gate of the compound type mosFET, The source of the second MOSFET (Q51) serves as the source of the compounded MOSFET. The drain of the first mosFET (Q1) is the drain of the compounded mosFET. A compounded MOSFET characterized by being configured to function.

6. In the compounded MOSFET according to claim 5, A resistor (R51), a Zener diode (Z51), and a capacitor (C51) are provided as a circuit for generating the constant voltage, and a first terminal of the resistor (R51) is connected to the drain of a first MOS FET (Q1), or to a power supply or other device. One end of the Zener diode (Z51) and the capacitor (C51) connected in parallel to generate a constant voltage with a current flowing through the resistor (R51) is connected to the second terminal of the resistor (R51) and to the second terminal of the resistor (R61). The other end of the Zener diode (Z51) and the capacitor (C51) connected in parallel is connected to the first terminal of the resistor (R31). A compounded type MOSFET, characterized in that the constant voltage circuit is configured to be formed by a resistor, a Zener diode, and a capacitor.

7. In the compounded MOSFET according to claim 6, The first terminal of the resistor (R51) is connected to the positive power supply when connected to the power supply, or to the drain of another MOSFET located on the higher potential side when connected to the device; The anode, which is one end of the Zener diode (Z51), is connected to the first terminal of the resistor (R31), By applying a high-voltage n-channel mosFET to the first mosFET (Q1) and a low-voltage n-channel mosFET to the second mosFET (Q51) that has a low source input impedance and an allowable current that is the same as that of the first mosFET (Q1) or larger than the current limited by the resistor (R41), In this case, the compounded MOSFET operates as an n-channel MOSFET. The source input impedance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second MOSFET (Q51) is small, so the Miller effect is suppressed. Maintaining a high breakdown voltage of the first mosFET (Q1), A high-voltage composite n-channel MOSFET characterized in that the first and second MOSFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) to below the allowable current.

8. In the compounded MOSFET according to claim 6, The first terminal of the resistor (R51) is connected to a negative power supply when connected to a power supply, or to the drain of another MOSFET arranged on the lower potential side when connected to a device; The cathode of the Zener diode (Z51) is connected to the first terminal of the resistor (R31), By applying a high-voltage p-channel mosFET to the first mosFET (Q1) and a low-voltage p-channel mosFET to the second mosFET (Q51) that has a low source input impedance and an allowable current that is the same as that of the first mosFET (Q1) or that is larger than the current limited by the resistor (R41), In this case, the compounded MOSFET operates as a p-channel MOSFET. The source input impedance is smaller than that of the first mosFET (Q1), The voltage change between the drain and gate of the second MOSFET (Q51) is small, so the Miller effect is suppressed. Maintaining a high breakdown voltage of the first mosFET (Q1), A high-voltage composite p-channel MOSFET characterized in that the first and second MOSFETs (Q1, Q51) are configured to be protected from overcurrent by the resistor (R41) to below the allowable current.

9. In a circuit in which the positive output stage circuit is composed of a photocoupler (U101) and two or more N-stage n-channel MOS FETs (Q10i, i = 1 to N), The point of the positive output stage circuit with the highest potential is designated as node Hn, and the point of the positive output stage circuit with the lowest potential is designated as node Ln, The drain of the mosFET (Q10N) is connected to the node Hn, the drain of the mosFET (Q10i, i=N-1) is connected to its source, the drain of the mosFET (Q10i, i=N-2) is connected to its source, and so on, with the mosFETs being connected in series, and the drain of the last mosFET (Q101) being connected to the source of the mosFET (Q102), N resistors (R10i, i = 1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R10N) is connected to node Hn, a second terminal of the resistor (R10i, i = N-1) is connected to a first terminal of the resistor (R10i, i = N-1), and so on, with the resistors connected in series, and the first terminal of the last resistor (R101) is connected to the second terminal of the resistor (R102), A circuit for generating a constant voltage is provided. A second terminal of the resistor (R101) is connected to the positive side of the constant voltage end of the constant voltage circuit, and a negative side of the constant voltage end of the constant voltage circuit is connected to a node Ln, A second terminal of the resistor (R10N) is connected to the gate of the mosFET (Q10N); The second terminal of the resistor (R10i, i=N-1) is connected to the gate of the mosFET (Q10i, i=N-1), and so on until the second terminal of the resistor (R10i) is connected to the gate of the mosFET (Q10i), and finally the second terminal of the resistor (R101) is connected to the gate of the mosFET (Q101). A predetermined bias voltage is applied to the gate of each mosFET (Q10i, i=1 to N), The source of the mosFET (Q101) is connected to the collector of the photocoupler (U101) via a resistance of 0 Ω or more, and the emitter is connected to a node Ln. connecting node Hn to a positive power supply for application to said positive output stage; Node Ln is connected to the output end, The single mosFET (Q101) The compounded n-channel MOSFET of claim 7 is applied, A positive-side output stage characterized in that the compounded n-channel mosFET of claim 3 is applied to each of the single mosFETs (Q10i, i = 2 to N) to have a source current control function that is speeded up by the compounded n-channel mosFET.

10. In a circuit in which the negative side output stage circuit is composed of a photocoupler (U201) and two or more N stages of n-channel MOS FETs (Q20j, j = 1 to N), The point of the negative output stage circuit with the highest potential is designated as node Hn, and the point of the negative output stage circuit with the lowest potential is designated as node Ln, The drain of the mosFET (Q20N) is connected to the node Hn, the drain of the mosFET (Q20j, j=N-1) is connected to its source, the drain of the mosFET (Q20j, j=N-2) is connected to its source, and so on, with the mosFETs connected in series, and the drain of the last mosFET (Q201) is connected to the source of the mosFET (Q202), N resistors (R20j, j=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R20N) is connected to node Hn, a second terminal of the resistor (R20j, j=N-1) is connected to a first terminal of the resistor (R20j, j=N-1), and so on, with the resistors connected in series, and the first terminal of the last resistor (R201) is connected to the second terminal of the resistor (R202), A circuit for generating a constant voltage is provided. A second terminal of the resistor (R201) is connected to the positive side of the constant voltage end of the constant voltage circuit, and a negative side of the constant voltage end of the constant voltage circuit is connected to a node Ln, A second terminal of the resistor (R20N) is connected to the gate of the mosFET (Q20N); The second terminal of the resistor (R20j, j=N-1) is connected to the gate of the mosFET (Q20j, j=N-1), and so on until the second terminal of the resistor (R20j) is connected to the gate of the mosFET (Q20j), and finally the second terminal of the resistor (R201) is connected to the gate of the mosFET (Q201), thereby applying a predetermined bias voltage to the gate of each of the mosFETs (Q20j, j=1 to N), The source of the mosFET (Q201) is connected to the collector of the photocoupler (U201) via a resistance of 0 Ω or more, and the emitter is connected to a node Ln, Node Hn is connected to the output for application to the negative output stage; Node Ln is connected to a negative power supply; The single mosFET (Q201) The compounded n-channel MOSFET of claim 7 is applied, A negative-side output stage characterized in that the compounded n-channel mosFET of claim 3 is applied to each of the single mosFETs (Q20j, j = 2 to N) to have a sink current control function that is speeded up by the compounded n-channel mosFET.

11. In a circuit in which the positive output stage circuit is composed of a photocoupler (U101) and two or more N stages of p-channel MOS FETs (Q10i, i = 1 to N), The point of the positive output stage circuit with the highest potential is a node Hp, and the point of the positive output stage circuit with the lowest potential is a node Lp. The drain of the mosFET (Q10N) is connected to the node Lp, the drain of the mosFET (Q10i, i=N-1) is connected to its source, the drain of the mosFET (Q10i, i=N-2) is connected to its source, and so on, with the mosFETs being connected in series, and the drain of the last mosFET (Q101) being connected to the source of the mosFET (Q102), N resistors (R10i, i = 1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R10N) is connected to node Lp, a second terminal of the resistor (R10i, i = N-1) is connected to a first terminal of the resistor (R10i, i = N-1), and so on, with the resistors connected in series, and the first terminal of the last resistor (R101) is connected to the second terminal of the resistor (R102), A circuit for generating a constant voltage is provided. A second terminal of the resistor (R101) is connected to the negative side of the constant voltage end of the constant voltage circuit, and a positive side of the constant voltage end of the constant voltage circuit is connected to a node Hp, A second terminal of the resistor (R10N) is connected to the gate of the mosFET (Q10N); The second terminal of the resistor (R10i, i=N-1) is connected to the gate of the mosFET (Q10i, i=N-1), and so on until the second terminal of the resistor (R10i) is connected to the gate of the mosFET (Q10i), and finally the second terminal of the resistor (R101) is connected to the gate of the mosFET (Q101), thereby applying a predetermined bias voltage to the gate of each mosFET (Q10i, i=1 to N), The source of the mosFET (Q101) is connected to the emitter of the photocoupler (U101) via a resistance of 0 Ω or more, and the collector of the mosFET (Q101) is connected to a node Hp. connecting node Hp to a positive power supply for application to said positive output stage; Node Lp is connected to the output end, The single mosFET (Q101) The compounded p-channel MOS FET of claim 8 is applied, A positive-side output stage characterized in that the compounded p-channel mosFET of claim 4 is applied to each of the single mosFETs (Q10i, i = 2 to N) to have a source current control function that is speeded up by the compounded p-channel mosFET.

12. In a circuit in which the negative side output stage circuit is composed of a photocoupler (U201) and two or more N stages of p-channel MOS FETs (Q20j, j = 1 to N), The point of the negative output stage circuit with the highest potential is a node Hp, and the point of the negative output stage circuit with the lowest potential is a node Lp. The drain of the mosFET (Q20N) is connected to the node Lp, the drain of the mosFET (Q20j, j=N-1) is connected to its source, the drain of the mosFET (Q20j, j=N-2) is connected to its source, and so on, with the mosFETs being connected in series, and the drain of the last mosFET (Q201) being connected to the source of the mosFET (Q202), N resistors (R20j, j=1 to N) are provided to apply a bias voltage to the gate of each mosFET, a first terminal of the resistor (R20N) is connected to node Lp, a second terminal of the resistor (R20j, j=N-1) is connected to a first terminal of the resistor (R20j, j=N-1), and so on, with the resistors connected in series, and the first terminal of the last resistor (R201) is connected to the second terminal of the resistor (R202), A circuit for generating a constant voltage is provided. A second terminal of the resistor (R201) is connected to the negative side of the constant voltage end of the constant voltage circuit, and a positive side of the constant voltage end of the constant voltage circuit is connected to a node Hp, A second terminal of the resistor (R20N) is connected to the gate of the mosFET (Q20N); The second terminal of the resistor (R20j, j=N-1) is connected to the gate of the mosFET (Q20j, j=N-1), and so on until the second terminal of the resistor (R20j) is connected to the gate of the mosFET (Q20j), and finally the second terminal of the resistor (R201) is connected to the gate of the mosFET (Q201), thereby applying a predetermined bias voltage to the gate of each of the mosFETs (Q20j, j=1 to N), The source of the mosFET (Q201) is connected to the emitter of the photocoupler (U201) via a resistor of 0Ω or more, and the collector of the mosFET (Q201) is connected to a node Hp. Node Hp is connected to the output for application to the negative output stage; Node Lp is connected to the negative power supply; The single mosFET (Q201) The compounded p-channel MOS FET of claim 8 is applied, A negative-side output stage characterized in that the compounded p-channel mosFET of claim 4 is applied to each of the single mosFETs (Q20j, j = 2 to N) to have a sink current control function that is speeded up by the compounded p-channel mosFET.

13. an input stage having a low-voltage amplification section, an output stage having a high-voltage amplification section, and a photocoupler interposed between the input stage and the output stage; the output stage has a positive output stage connected to a positive power supply for controlling a source current, and a negative output stage connected to a negative power supply for controlling a sink current; The photocoupler also includes a photocoupler (U101) that controls the positive output stage and a photocoupler (U201) that controls the negative output stage, In a high-voltage amplifier, an input signal is amplified by the low-voltage amplifier, the amplified signal is introduced into the high-voltage amplifier via the photocoupler (U101, U201), and the amplified signal is output from an output terminal, The positive output stage includes two or more N mosFETs (Q10i, i = 1 to N), These mosFETs are connected in series in numerical order (Q10N, ..., Q102, Q101), and the photocoupler (U101) is connected to drive the source of the mosFET (Q101) via a resistance of 0 Ω or more, and these series-connected mosFETs (Q10i, i = 1 to N) and the photocoupler (U101) are arranged between the positive power supply and the output terminal, The negative output stage includes N identical mosFETs (Q20j, j=1 to N), These mosFETs are connected in series in numerical order (Q20N, ..., Q202, Q201), and the photocoupler (U201) is connected so that the source of the mosFET (Q201) is driven via a resistance of 0 Ω or more, and these series-connected mosFETs (Q20j, j = 1 to N) and the photocoupler (U201) are arranged between the negative power supply and the output terminal, N resistors (R10i, i = 1 to N) and a circuit or element (Z101) for generating a constant voltage are provided on the positive side output stage side, and these are connected in series in numerical order (R10N, ..., R102, R101, Z101), and are arranged between the positive power supply and the output terminal, thereby providing a bias voltage of a predetermined potential divided from the positive power supply to the output terminal to the gate of each mosFET (Q10i, i = 1 to N) of the positive side output stage; N resistors (R20j, j=1 to N) and a circuit or element (Z201) for generating a constant voltage are provided on the negative side output stage side, and these are connected in series in numerical order (R20N, ..., R202, R201, Z201), and are arranged between the negative power supply and the output terminal, thereby providing a bias voltage of a predetermined potential divided from the negative power supply to the output terminal to the gate of each MOSFET (Q20j, j=1 to N) of the negative side output stage; A high-voltage amplifier characterized in that a high-voltage amplifier section is configured to control a source current at a positive output stage and a sink current at a negative output stage.

14. 14. The high voltage amplifier of claim 13, The positive-side output stage of the high-voltage amplifier section is an output stage according to claim 9 or 11, in which the mosFET (Q10i, i = 1 to N) is replaced with a compounded mosFET; The negative-side output stage of the high-voltage amplifier section is an output stage according to claim 10 or claim 12, in which the mosFET (Q20j, j = 1 to N) is replaced with a compounded mosFET; A high-voltage amplifier configured to achieve high speed and wide bandwidth.

15. In the high-voltage amplifier according to claim 14, the mosFET (Q15i, i = 1 to N) which constitutes a compounded mosFET in combination with the mosFET (Q10i, i = 1 to N) and the mosFET (Q25j, j = 1 to N) which constitutes a compounded mosFET in combination with the mosFET (Q20j, j = 1 to N) When the mosFET (Q15i, i = 1 to N) of the positive side output stage configured with an n-channel or p-channel and the mosFET (Q25j, j = 1 to N) of the negative side output stage configured with an n-channel or p-channel, and the positive side output stage and the negative side output stage are configured with mosFETs of different channels, Let i and j be j = i for i = 2 to N, When the positive output stage and the negative output stage are configured with mosFETs of the same channel, Let i and j be i = 2 to N, and j = N + 2 - i. 2 (N-1) sets of resistors and capacitors of 0 Ω or more connected in series are provided. For each of the N-1 combinations of the mosFET (Q15i, Q25j) of the mosFET (Q15i) in the positive output stage and the mosFET (Q25j) in the negative output stage, The series-connected resistor and capacitor are connected between the source of the mosFET (Q15i) and the gate of the mosFET (Q25j), and the series-connected resistor and capacitor are connected between the source of the mosFET (Q25j) and the gate of the mosFET (Q15i); A high-voltage amplifier characterized in that it is configured so that high speed and wide bandwidth are achieved by a low-impedance source driving a high-impedance gate through a series-connected resistor and capacitor.

16. 15. The high voltage amplifier of claim 14, N sets of resistors and capacitors of 0 Ω or more connected in series are provided, These are connected in parallel to each of the N resistors (R10i, i = 1 to N) in the positive output stage, and N sets of resistors and capacitors of 0 Ω or more connected in series are further provided, These are connected in parallel to each of the N resistors (R20j, j = 1 to N) in the negative output stage, and this high-voltage amplifier is configured to prevent oscillation and provide stable, high-speed response.

17. 16. The high voltage amplifier of claim 15, The resistor and capacitor connected in series according to claim 16 are connected in parallel to each of the resistors (R10i, i = 1 to N) and the resistors (R20j, j = 1 to N) in the output stage; A high-voltage amplifier characterized by being configured to prevent oscillation, operate stably even under no load, and achieve high speed and wide bandwidth.

18. In the mosFET (Q10i, i=1 to N) and the mosFET (Q20j, j=1 to N) in the high-voltage amplifier according to claim 13, When the mosFET (Q10i, i = 1 to N) of the positive side output stage configured with an n-channel or p-channel and the mosFET (Q20j, j = 1 to N) of the negative side output stage configured with an n-channel or p-channel, and the positive side output stage and the negative side output stage are configured with mosFETs of different channels, Let i and j be j = i for i = 2 to N, When the positive output stage and the negative output stage are configured with mosFETs of the same channel, Let i and j be i = 2 to N, and j = N + 2 - i. 2 (N-1) sets of resistors and capacitors of 0 Ω or more connected in series are provided. For each of the N-1 combinations of the mosFET (Q10i, Q20j) of the mosFET (Q10i) in the positive output stage and the mosFET (Q20j) in the negative output stage, The series-connected resistor and capacitor are connected between the source of the mosFET (Q10i) and the gate of the mosFET (Q20j), and the series-connected resistor and capacitor are connected between the source of the mosFET (Q20j) and the gate of the mosFET (Q10i), A high voltage amplifier characterized in that a low impedance source drives a high impedance gate through a series connected resistor and capacitor, thereby achieving high speed response. Width board.

19. 14. The high voltage amplifier of claim 13, N sets of resistors and capacitors of 0 Ω or more connected in series are provided, These are connected in parallel to each of the N resistors (R10i, i = 1 to N) in the positive output stage, and N sets of resistors and capacitors of 0 Ω or more connected in series are further provided, These are connected in parallel to each of the N resistors (R20j, j = 1 to N) in the negative output stage, preventing oscillation and allowing stable operation even when there is no load.

20. 20. The high voltage amplifier of claim 18, The resistor and capacitor connected in series according to claim 19 are connected in parallel to each of the resistors (R10i, i = 1 to N) and the resistors (R20j, j = 1 to N) in the output stage; A high-voltage amplifier characterized by being configured to prevent oscillation and to have a stable, high-speed response.

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