Transistor safe operating area adaptive adjustment device and transistor application system

Abstract

The present invention relates to the technical field of transistor safe working area control, and specifically discloses a transistor safe working area adaptive adjustment device and a transistor application system, comprising: a current sampling unit, a voltage sampling unit, a drive adjustment unit and a transistor unit, wherein the current sampling unit is used to sample the working current of the transistor unit to obtain the current working current of the transistor unit; the voltage sampling unit is used to collect the saturation tube voltage drop of the transistor unit under the current working current; the drive adjustment unit is used to adaptively adjust the current working current or the saturation tube voltage drop according to load requirements to obtain the drive adjustment voltage of the transistor unit; the transistor unit can work in a safe working area according to the drive adjustment voltage, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤C‑K*Vce. The transistor safe operating area adaptive adjustment device provided by the present invention can accurately and effectively control the transistor to be in the safe operating area.

Description

Technical Field

[0001] The present invention relates to the technical field of transistor safe operating area control, and in particular to a transistor safe operating area adaptive adjustment device and a transistor application system. Background Art

[0002] The safe operating area of ​​a transistor refers to the range of voltage, current and other conditions under which a power semiconductor device can work normally as expected without causing damage. It is information used to confirm whether the transistor is working under safe conditions. In the manual or datasheet of a semiconductor device product, the safe operating area is usually indicated in the form of a coordinate image. The rectangular coordinate diagram of the safe operating area of ​​a conventional transistor is as follows: Figure 1 As shown, taking the transistor as an example, the horizontal coordinate of the safe working area coordinate diagram is Vce (collector-emitter voltage), and the vertical coordinate is Ice (collector-emitter current), and the range of the safe working area is the area surrounded by the curve and the coordinate axis. This boundary curve combines the following working limits of the device: maximum voltage, maximum current and maximum dissipated power. If the transistor continues to work in the unsafe working area, the internal current concentration will cause local heating, thus causing the device to degrade or even completely fail. In order to prevent the transistor from being damaged during use, it must be kept in the safe working area at all times, and the heat dissipation conditions must also be met for the power tube.

[0003] At present, there are few existing transistor safe operating area control methods. The conventional transistor safe operating area adjustment device schematic diagram is as follows: Figure 2 As shown in the figure, this control method collects the saturation tube voltage drop of the transistor and inputs it into the comparator for comparison and judgment. When its voltage exceeds the threshold voltage of the comparator, the transistor will be directly turned off instantly to achieve the purpose of protecting the transistor. Although this method can protect the transistor, it cannot linearly adjust the output state of the transistor, so the transistor cannot continuously output voltage and current, and even causes a large spike voltage at the moment of switching. At the same time, this method has a complex structure and uses more components, which will lead to higher costs.

[0004] Therefore, how to accurately and effectively control the transistor to be within the safe operating area has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the invention

[0005] The present invention provides a transistor safe operating area adaptive adjustment device and a transistor application system, which solve the technical problem existing in the related art that the transistor cannot be accurately and effectively controlled to be in the safe operating area.

[0006] As a first aspect of the present invention, a transistor safe operating area adaptive adjustment device is provided, which includes: a current sampling unit, a voltage sampling unit, a drive adjustment unit and a transistor unit, wherein the current sampling unit is electrically connected to the voltage sampling unit and the transistor unit respectively, the voltage sampling unit is electrically connected to the transistor unit, and the drive adjustment unit is electrically connected to the voltage sampling unit and the transistor unit respectively, the current sampling unit is used to sample the working current of the transistor unit to obtain the current working current of the transistor unit; the voltage sampling unit is used to collect the saturation tube voltage drop of the transistor unit under the current working current; the drive adjustment unit is used to adaptively adjust the current working current or the saturation tube voltage drop according to load requirements to obtain the drive adjustment voltage of the transistor unit; the transistor unit can work in the safe working area according to the drive adjustment voltage, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, wherein Vce represents the saturation tube voltage drop of the transistor unit under the current working current, and C and K both represent variable adjustment parameters.

[0007] Furthermore, the driving adjustment unit is used to adaptively adjust the current working current or the saturated tube voltage drop according to the load demand to obtain the driving adjustment voltage of the transistor unit, including: when the load demand is to obtain a current of a preset amplitude, the driving adjustment unit is used to adaptively adjust the saturated tube voltage drop according to the transistor unit's own power consumption to obtain the driving adjustment voltage of the transistor unit; when the load demand is to obtain a voltage of a preset amplitude, the driving adjustment unit is used to adaptively adjust the current working current according to the transistor unit's own power consumption to obtain the driving adjustment voltage of the transistor unit.

[0008] Furthermore, the driving adjustment unit includes: a voltage and current conversion unit and a current driving unit, the voltage and current conversion unit is connected to the voltage sampling unit, and the current driving unit is respectively connected to the voltage and current conversion unit and the transistor unit; the voltage and current conversion unit is used to convert the saturated tube voltage drop under the current working current into a saturated tube current; the current driving unit is used to adaptively adjust the saturated tube current or the current working current according to the load demand to obtain the driving adjustment voltage of the transistor unit.

[0009] Further, the voltage and current conversion unit includes: a first triode, a second triode, a third triode, a fourth triode, a first constant current source and a fourth resistor, the emitter of the first triode is the input end of the voltage and current conversion unit, and is used to connect the voltage sampling unit, the collector of the first triode is connected to the positive electrode of the first constant current source, the base of the first triode is connected to the base of the second triode, the emitter of the second triode is connected to the power supply, and the collector of the second triode is connected to the collector of the third triode. The emitter of the third triode is connected to the signal ground, the collector of the third triode is connected to the base of the third triode, the base of the third triode is connected to the base of the fourth triode, the collector of the fourth triode is the output end of the voltage and current conversion unit, and is used to connect the current driving unit, the emitter of the fourth triode is connected to the signal ground, the negative electrode of the first constant current source is connected to the signal ground, one end of the fourth resistor is connected to the base of the third triode, and the other end of the fourth resistor is connected to the signal ground.

[0010] Furthermore, the current driving unit includes a second constant current source, a positive electrode of the second constant current source is connected to the power supply, and a negative electrode of the second constant current source is connected to the output end of the voltage and current conversion unit.

[0011] Furthermore, the drive adjustment unit includes a voltage drive unit, which is respectively connected to the voltage sampling unit and the transistor unit, and the voltage drive unit is used to adaptively adjust the current working current or the saturated tube voltage drop according to the load requirement to obtain the drive adjustment voltage of the transistor unit.

[0012] Further, the current sampling unit includes a first resistor, one end of the first resistor is connected to a power supply, and the other end of the first resistor is respectively connected to the voltage sampling unit and the transistor unit.

[0013] Further, the voltage sampling unit includes a second resistor and a third resistor, one end of the second resistor is connected to the current sampling unit, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is connected to the transistor unit, and the connection end of the second resistor and the third resistor is connected to the drive adjustment unit.

[0014] Further, the transistor unit comprises a transistor, a control end of the transistor is connected to the driving adjustment unit, an input end of the transistor is respectively connected to the voltage sampling unit and the current sampling unit, and an output end of the transistor is connected to the voltage sampling unit.

[0015] As another aspect of the present invention, a transistor application system is provided, which includes: a preamplifier module, a load and the transistor safe working area adaptive adjustment device mentioned above, the preamplifier module is connected to the transistor unit of the transistor safe working area adaptive adjustment device, the load is connected to the output end of the transistor safe working area adaptive adjustment device, the preamplifier module is used to amplify the input signal to obtain an amplified processing signal; the transistor unit in the transistor safe working area adaptive adjustment device is used to amplify the amplified processing signal in the safe working area, and the transistor safe working area adaptive adjustment device can adaptively adjust the driving adjustment voltage of the transistor unit according to the load demand, so that the transistor unit can work in the safe working area, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, wherein Vce represents the saturation tube voltage drop of the transistor unit under the current working current, and C and K both represent variable adjustment parameters.

[0016] The transistor safe working area adaptive adjustment device provided by the present invention samples the working current of the transistor unit in real time through the current sampling unit, and samples the saturation tube voltage drop of the transistor unit through the voltage sampling unit, so that the driving adjustment unit can adaptively adjust the current working current or the saturation tube voltage drop according to the load demand to obtain the driving adjustment voltage that can make the transistor unit work in the safe working area, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, this transistor safe operating area adaptive adjustment device can make the transistor unit work in the safe operating area through adaptive adjustment, can accurately and effectively control the maximum dissipated power of the transistor, and improve the reliability of the transistor unit. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to provide further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention, but do not constitute a limitation of the present invention.

[0018] Figure 1 It is a rectangular coordinate schematic diagram of the safe working area of ​​a transistor in the prior art.

[0019] Figure 2 The figure is a schematic diagram of a transistor safe operating area adjustment device in the prior art.

[0020] Figure 3 This is a structural block diagram of the transistor safe operating area adaptive adjustment device provided by the present invention.

[0021] Figure 4a This is a structural block diagram of a specific implementation of the transistor safe operating area adaptive adjustment device provided by the present invention.

[0022] Figure 4b A circuit schematic diagram of a specific implementation of the transistor safe operating area adaptive adjustment device provided by the present invention.

[0023] Figure 5 A rectangular coordinate diagram of the transistor safe operating area of ​​the transistor safe operating area adaptive adjustment device provided by the present invention.

[0024] Figure 6 This is a structural block diagram of the transistor application system provided by the present invention.

[0025] Figure 7 This is an application output waveform diagram of the transistor safe operating area adaptive adjustment device provided by the present invention. DETAILED DESCRIPTION

[0026] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is only a part of the embodiment of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so as to describe the embodiments of the present invention described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0029] In this embodiment, a transistor safe operating area adaptive adjustment device is provided. Figure 3 is a structural block diagram of a transistor safe operating area adaptive adjustment device 10 according to an embodiment of the present invention. Figure 3As shown, it includes: a current sampling unit 100, a voltage sampling unit 200, a drive adjustment unit 300 and a transistor unit 400, wherein the current sampling unit 100 is electrically connected to the voltage sampling unit 200 and the transistor unit 400 respectively, the voltage sampling unit 200 is electrically connected to the transistor unit 400, and the drive adjustment unit 300 is electrically connected to the voltage sampling unit 200 and the transistor unit 400 respectively. The current sampling unit 100 is used to sample the working current of the transistor unit to obtain the current working current of the transistor unit; the voltage sampling unit 200 is used to collect the saturation tube voltage drop of the transistor unit under the current working current; the drive adjustment unit 300 is used to adaptively adjust the current working current or the saturation tube voltage drop according to load demand to obtain the drive adjustment voltage of the transistor unit; the transistor unit 400 can work in a safe working area according to the drive adjustment voltage, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, wherein Vce represents the saturation tube voltage drop of the transistor unit under the current working current, and C and K both represent variable adjustment parameters.

[0030] In the embodiment of the present invention, the current sampling unit 100 can collect the current working current of the transistor unit in real time. Specifically, one end of the current sampling unit 100 is connected to the power supply, and the other end is connected to the transistor unit and the voltage sampling unit respectively. The voltage drop of the current sampling unit 100 can be determined based on the current working current collected by the current sampling unit 100, and then the voltage sampling unit 200 can determine the saturated tube voltage drop of the transistor unit under the current working current based on the current working current collected by the current sampling unit 100 when sampling the saturated tube voltage drop of the transistor unit.

[0031] At this time, the driving adjustment unit 300 can adaptively adjust the saturated tube voltage drop or the current working current according to the load demand. Specifically, when the load demand is to extract a large current, the driving adjustment unit 300 can limit the output amplitude of the transistor unit through adaptive adjustment to reduce the saturated tube voltage drop. When the load demand is a large output amplitude, the driving adjustment unit 300 can limit the output current of the transistor unit through adaptive adjustment so that the power consumption of the transistor unit itself is limited within a safe range, that is, the driving adjustment voltage of the transistor unit obtained can control the transistor unit to work in a safe working area. Through this adaptive adjustment method, the transistor can work accurately and effectively in the safe working area.

[0032] In summary, the transistor safe working area adaptive adjustment device provided by the present invention samples the working current of the transistor unit in real time through the current sampling unit, and samples the saturation tube voltage drop of the transistor unit through the voltage sampling unit, so that the driving adjustment unit can adaptively adjust the current working current or the saturation tube voltage drop according to the load demand to obtain the driving adjustment voltage that can make the transistor unit work in the safe working area, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, this transistor safe operating area adaptive adjustment device can make the transistor unit work in the safe operating area through adaptive adjustment, can accurately and effectively control the maximum dissipated power of the transistor, and improve the reliability of the use of the transistor unit.

[0033] In an embodiment of the present invention, the driving adjustment unit is used to adaptively adjust the current working current or the saturated tube voltage drop according to load requirements to obtain the driving adjustment voltage of the transistor unit, including: when the load requirement is to obtain a current of a preset amplitude, the driving adjustment unit is used to adaptively adjust the saturated tube voltage drop according to the transistor unit's own power consumption to obtain the driving adjustment voltage of the transistor unit; when the load requirement is to obtain a voltage of a preset amplitude, the driving adjustment unit is used to adaptively adjust the current working current according to the transistor unit's own power consumption to obtain the driving adjustment voltage of the transistor unit.

[0034] It should be understood that the driving adjustment unit can perform different adaptive adjustments according to different load requirements. When the load requirement is to obtain a current of a preset amplitude, for example, when a large current is required, the driving adjustment unit can adaptively adjust the saturation tube voltage drop according to the transistor unit's own power consumption remaining unchanged, that is, adaptively adjust the saturation tube voltage drop according to the current working current, and then obtain the driving adjustment voltage of the transistor unit, so that the transistor unit can operate in a safe working area; similarly, when the load requirement is to obtain a voltage of a preset amplitude, for example, when a large voltage is required, the driving adjustment unit can adaptively adjust the current working current according to the transistor unit's own power consumption remaining unchanged, so that the transistor unit can operate in a safe working area.

[0035] Therefore, the transistor safe operating area adaptive adjustment device of the embodiment of the present invention can automatically adjust the transistor current Io according to the saturation tube voltage drop Vce of the transistor unit, and can also automatically adjust the saturation tube voltage drop Vce of the transistor according to the transistor current Io, thereby achieving a bidirectional adjustment effect. The transistor safe operating area adaptive adjustment device can automatically and accurately control the safe operating area of ​​the transistor: 0 ≤ Io ≤ CK*Vce, where K and C are adjustable constant parameters. Therefore, the transistor safe operating area adaptive adjustment device can control the transistor to always be within the safe operating area, thereby accurately and effectively limiting the maximum dissipated power of the transistor and improving the reliability of the transistor.

[0036] In the embodiment of the present invention, Figure 4b As shown, the current sampling unit 100 includes a first resistor R1, one end of the first resistor R1 is connected to a power supply VCC, and the other end of the first resistor R1 is connected to the voltage sampling unit 200 and the transistor unit 400 respectively.

[0037] It should be noted that, in an embodiment of the present invention, in order to reduce energy loss, the first terminal R1 can be specifically implemented by aluminum wire, that is, by using the aluminum wire as a sampling resistor to sample the real-time working current of the transistor unit. Since the resistance of the aluminum wire sampling resistor is extremely small, for example, it can be in the milliohm level, it can effectively reduce energy loss.

[0038] like Figure 4b As shown, the voltage sampling unit 200 includes a second resistor R2 and a third resistor R3, one end of the second resistor R2 is connected to the current sampling unit 100, the other end of the second resistor R2 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to the transistor unit 400, and the connection end of the second resistor R2 and the third resistor R3 is connected to the drive adjustment unit 300.

[0039] Specifically, Figure 4b As shown, the transistor unit 400 includes a transistor Q0, a control terminal b of the transistor Q0 is connected to the driving adjustment unit 300, an input terminal c of the transistor Q0 is respectively connected to the voltage sampling unit 200 and the current sampling unit 100, and an output terminal e of the transistor Q0 is connected to the voltage sampling unit 200.

[0040] It should be understood that one end of the second resistor R2 is connected to the other end of the first resistor R1, one end of the second resistor R2 is also connected to the input end c of the transistor Q0, and the other end of the third resistor is connected to the output end e of the transistor Q0.

[0041] As an implementation manner of a driving adjustment unit, the driving adjustment unit 300 includes: a voltage and current conversion unit 310 and a current driving unit 320, the voltage and current conversion unit 310 is connected to the voltage sampling unit 200, and the current driving unit 320 is respectively connected to the voltage and current conversion unit 310 and the transistor unit 400; the voltage and current conversion unit 310 is used to convert the saturated tube voltage drop under the current working current into a saturated tube current; the current driving unit 320 is used to adaptively adjust the saturated tube current or the current working current according to the load demand to obtain the driving adjustment voltage of the transistor unit.

[0042] Specifically, Figure 4a As shown, the voltage and current conversion unit 310 includes: a first transistor Q1, a second transistor Q2, a third transistor Q3, a fourth transistor Q4, a first constant current source i1 and a fourth resistor R4, the emitter of the first transistor Q1 is the input end of the voltage and current conversion unit 310, and is used to connect the voltage sampling unit 200, the collector of the first transistor Q1 is connected to the positive electrode of the first constant current source i1, the base of the first transistor Q1 is connected to the base of the second transistor Q2, the emitter of the second transistor Q2 is connected to the power supply VCC, the collector of the second transistor Q2 is connected to the collector of the third transistor Q3 The emitter of the third triode Q3 is connected to the signal ground GND, the collector of the third triode Q3 is connected to the base of the third triode Q3, the base of the third triode Q3 is connected to the base of the fourth triode Q4, the collector of the fourth triode Q4 is the output end of the voltage and current conversion unit 310, and is used to connect the current driving unit 320, the emitter of the fourth triode Q4 is connected to the signal ground GND, the negative electrode of the first constant current source i1 is connected to the signal ground GND, one end of the fourth resistor R4 is connected to the base of the third triode Q3, and the other end of the fourth resistor R4 is connected to the signal ground GND.

[0043] Specifically, the current driving unit 320 includes a second constant current source i2 , a positive electrode of the second constant current source i2 is connected to the power supply VCC, and a negative electrode of the second constant current source i2 is connected to the output end of the voltage and current conversion unit 310 .

[0044] In the embodiment of the present invention, the second resistor R2 is proportional to the third resistor R3, and the proportionality coefficient is n; the second resistor R2 and the third resistor R3 are both high-resistance resistors of the same type, and are used to sample the saturation tube voltage drop Vce of the transistor Q0, where Vce=Vc-Ve.

[0045] In addition, the first transistor Q1 and the second transistor Q2 in the embodiment of the present invention constitute a first mirror proportional current circuit, whose proportional coefficient m is the ratio of the emitter area of ​​the first transistor Q1 to the second transistor Q2; the third transistor Q3 and the fourth transistor Q4 constitute a second mirror proportional current circuit, whose proportional coefficient α is the ratio of the emitter area of ​​the third transistor Q3 to the fourth transistor Q4; the first constant current source i1 serves as a bias current of the first mirror proportional current circuit.

[0046] The safe operating area of ​​the transistor Q0 can be precisely adjusted by setting the proportionality coefficient m, the proportionality coefficient n and the proportionality coefficient α.

[0047] It should be noted that the transistor Q0 can be a bipolar transistor or a field effect transistor.

[0048] Therefore, the adaptive adjustment device for the transistor safe working area provided by the present invention can not only automatically adjust the transistor Q0 current Io according to the saturation tube voltage drop Vce of the transistor Q0, but also automatically adjust the saturation tube voltage drop Vce of the transistor Q0 according to the transistor Q0 current Io, thereby achieving a bidirectional adjustment effect. The device can automatically and accurately control the safe working area of ​​the transistor Q0: 0 ≤ Io ≤ CK*Vce, where K and C are adjustable constant parameters, K= ,C= , just fitting the safe working area of ​​the transistor Q0, so the device can control the transistor Q0 to always be in the safe working area, which can accurately and effectively limit the maximum dissipated power of the transistor Q0 and improve the reliability of the use of the transistor Q0.

[0049] In the embodiment of the present invention, the specific working principle is that when a large-amplitude voltage signal needs to be output according to the load demand, in order to ensure that the power consumption of the transistor is within a safe range, the current of the transistor is adaptively adjusted. Specifically, since the current of the first constant current source i1 is constant, the current of the second triode Q2 is determined by the voltage superposition of the first triode Q1, the second resistor R2 and the first resistor R1. When the sum of the voltage values ​​of the second resistor R2 and the first resistor R1 is larger, the current flowing through the second triode Q2 is also larger; when the current of the second triode Q2 gradually increases to make the third triode Q3 and the fourth triode Q4 turned on, the fourth triode Q4 will gradually extract the control end current of the transistor Q0. Since the driving current of the control end of the transistor Q0 is the current of the second constant current source i2, that is, the driving current of the control end of the transistor Q0 is constant, therefore, when the current drawn downward by the fourth triode Q4 is larger, the current flowing into the control end of the transistor Q0 is smaller, so the output current of the transistor Q0, that is, the transistor current Io, is also reduced.

[0050] Since the current of the second transistor Q2 is determined by the voltage superposition of the first transistor Q1, the second resistor R2 and the first resistor R1, the voltage between the base and the emitter of the first transistor Q1 is almost constant, so the current of the second transistor Q2 mainly depends on the sum of the voltages of the second resistor R2 and the first resistor R1. When the voltage on the first resistor R1 increases due to the increase in the real-time working current of the transistor, the voltage difference on the second resistor R2 is required to be smaller to ensure that the current of the second transistor Q2 remains unchanged. Therefore, when the current flowing through the first resistor R1 is larger, the voltage value on the first resistor R1 is also larger. At this time, if the voltage on R2 is also large (Vce is large), the current of the second transistor Q2 will increase accordingly. When the current on the second transistor Q2 exceeds Vbe / R4, the excess current will turn on the third transistor Q3 and the fourth transistor Q4, and the fourth transistor Q4 will extract the control terminal current of the transistor Q0 to reduce the current of the transistor Q0, forming a negative feedback regulation mechanism. Therefore, when the real-time operating current of the transistor increases, the operating current of the transistor can be reduced through the adaptive adjustment mechanism.

[0051] Therefore, the driving adjustment unit of the embodiment of the present invention can adaptively linearly adjust the current or voltage of the control end of the transistor Q0. When the load requires a large current, the output amplitude of the transistor Q0 will be automatically limited to reduce its own Vce voltage. When the load requires a large output amplitude, the output current of the transistor Q0 will be limited to limit the power consumption P of the transistor Q0 to a safe range, ensuring that the power consumption of the transistor Q0 is within a safe range. Figure 5 The oblique line range of the rectangular coordinate system shown is the safe operating area of ​​the transistor.

[0052] In the embodiment of the present invention, the following Figure 4b The specific working principle of the safe operating area of ​​the transistor is explained in detail.

[0053] In the embodiment of the present invention, the turn-on voltage of each transistor can be specifically set to Vbe; R1 is an aluminum wire sampling resistor with a very small resistance value; R2 and R3 are voltage-dividing sampling resistors with relatively large resistance values; R4 is a shunt resistor with relatively large resistance value; Q0, Q1, Q2, Q3, and Q4 are all transistors; i1 and i2 are both constant current sources; Vt represents the temperature voltage equivalent, and Vt=26mV (T=300K) at room temperature; Is represents the reverse saturation current of the transistor; and Ic represents the collector current of the transistor.

[0054] According to the current characteristic formula of the transistor: I=Is* (1), by converting formula (1), we can get: Vbe = Vt * ln ( +1)(2), due to Much greater than 1, within the allowable error range, formula (2) can be simplified to: Vbe = Vt * ln ( )(3), therefore, when the current Ic increases by θ times, the turn-on voltage of the transistor is: Vbe1=Vt*ln( ) (4), the change of Vbe is: ΔVbe=Vbe1-Vbe=Vt*ln( )- Vt*ln( )=Vt*ln(θ)(5).

[0055] Depend on Figure 4b It can be seen that, due to the large current amplification factor β of the transistor, its collector current Ic is much larger than the base current Ib, so its base current Ib can be ignored within the error tolerance range. m represents the ratio of the emitter area of ​​the first transistor Q1 to the second transistor Q2. Therefore, in static operation, the collector current of the second transistor Q2 is the collector current of the first transistor Q1. times.

[0056] Since the first constant current source i1 is the bias current of the collector of the first transistor Q1, that is, Ic1=i1, the collector current of the second transistor Q2 is: Ic2= = (6) In static operation, the third transistor Q3 and the fourth transistor Q4 are in a critical cut-off state. At this time, the current on the shunt resistor, that is, the fourth resistor R4, is: IR4 = (7), so when the third transistor Q3 and the fourth transistor Q4 are in critical state, the ratio of their currents θ can be solved by combining formula (6) and formula (7): θ = = m* * (8).

[0057] Combined with the transistor current characteristics, and then according to formula (5) and formula (8) two equations are solved together to obtain: ΔVbe = Vt*ln(θ) = Vt*ln(m* * )(9).

[0058] In the embodiment of the present invention, the Vbe of the second transistor Q2 is composed of two parts: the voltage drop of the working current Io of the transistor Q0 on the first resistor R1, and the voltage divided by (Vc-Ve) on the second resistor R2 and the third resistor R3. Therefore, the condition for the third transistor Q3 and the fourth transistor Q4 to exit the critical cut-off state is: ΔVbe = Io*R1+( )*R1(10), after transforming formula (10), we can get: Io= - ( )* (11).

[0059] Substituting formula (9) into formula (11) and simplifying it, we can get: Io = = - (12).

[0060] Since the voltage difference between the input terminal c and the output terminal e of transistor Q0 is: Vce=Vc-Ve (13), substituting formula (13) into formula (12) yields: Io= - (14).

[0061] Since R3=n*R2, substituting it into formula (14) yields: Io= - *Vce(15).

[0062] Let parameter C = , parameter K = , then formula (15) can be further transformed into: Io=CK*Vce (16), according to the critical condition, the safe operating area boundary line of the transistor Q0 is obtained, then the safe operating area of ​​the transistor in the embodiment of the present invention under the full range conditions is expressed as: 0≤ Io ≤ CK*Vce, (C= , K = )(17).

[0063] From the above formulas (16) and (17), we know that C represents a constant, that is, the maximum output current of transistor Q0, K represents the slope of Io changing with Vce, and the output current Io of transistor Q0 is in a negative linear relationship with its saturation tube voltage drop Vce, which just fits the safe working area of ​​transistor Q0. The rectangular coordinate diagram of the fitting curve is as follows: Figure 5 As shown in the figure, the horizontal axis is Vce, the vertical axis is Io, and the safe working area is the area surrounded by the oblique line and the coordinate axis. This boundary area can clearly show the maximum voltage, maximum current, maximum power dissipation of transistor Q0 and the corresponding maximum output current Io values ​​under different Vce voltages.

[0064] At the same time, the embodiment of the present invention only needs to set the resistance values ​​of the first resistor R1 and the fourth resistor R4 and the values ​​of the proportional coefficients m and n to obtain the corresponding safe operating area of ​​the transistor Q0: 0≤ Io ≤ CK*Vce. Therefore, the embodiment of the present invention can easily adjust different linear regions to match the safe operating area of ​​the transistor Q0 with different process characteristics, thereby ensuring that the transistor Q0 is always in the safe operating area during use.

[0065] In addition, the first resistor R1 in the embodiment of the present invention can specifically use aluminum wire as a resistor, which has an extremely small resistance value of milliohm level. Therefore, the power consumption of the aluminum wire sampling resistor is extremely low, the heat generated is almost negligible, and its service life is increased, and the cost is extremely low.

[0066] As another implementation of the driving adjustment unit, the driving adjustment unit 300 includes a voltage driving unit, which is respectively connected to the voltage sampling unit and the transistor unit, and the voltage driving unit is used to adaptively adjust the current working current or the saturated tube voltage drop according to the load requirement to obtain the driving adjustment voltage of the transistor unit.

[0067] In an embodiment of the present invention, the voltage driving unit includes an adjustable resistor.

[0068] It should be understood that the driving adjustment unit can specifically adjust the driving adjustment voltage of the transistor unit through an adjustable resistor.

[0069] In summary, the transistor safe operating area adaptive adjustment device provided by the present invention has extremely high adaptive adjustment accuracy, stable performance, simple structure, high reliability and low cost.

[0070] As another embodiment of the present invention, a transistor application system is provided, wherein: Figure 6 As shown, it includes: a preamplifier module 20, a load 30 and the transistor safe working area adaptive adjustment device 10 mentioned above, the preamplifier module 20 is connected to the transistor unit of the transistor safe working area adaptive adjustment device 10, the load 30 is connected to the output end of the transistor safe working area adaptive adjustment device 10, the preamplifier module 20 is used to amplify the input signal to obtain an amplified processing signal; the transistor unit in the transistor safe working area adaptive adjustment device 10 is used to amplify the amplified processing signal in the safe working area, and the transistor safe working area adaptive adjustment device can adaptively adjust the driving adjustment voltage of the transistor unit according to the load demand, so that the transistor unit can work in the safe working area, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, wherein Vce represents the saturation tube voltage drop of the transistor unit under the current working current, and C and K both represent variable adjustment parameters.

[0071] As an application block diagram of a transistor safe operating area adaptive adjustment device, such as Figure 6As shown, the transistor safe working area adaptive adjustment device of the present invention is specifically applied to the output stage of the audio power amplifier in the embodiment of the present invention. The input signal is amplified by the preamplifier module and then transmitted to the control terminal b of the output transistor Q0, and then the final signal is output after amplification by the transistor Q0. When the signal amplitude at the input end is large, and the load draws a large current from the output end Vout at the same time, the power consumption of the transistor Q0 will rise sharply, causing the heat of the transistor to increase sharply, thereby causing the output transistor Q0 to degrade or even completely fail. In order to prevent the transistor from being damaged in this case, the transistor safe working area adaptive adjustment device of the present invention will gradually suppress the amplitude of the output signal, forcibly pull the transistor Q0 back to the safe working area, reduce the power consumption of the transistor Q0, and ensure that the output tube will not be damaged.

[0072] The application output waveform diagram of the transistor safe operating area adaptive adjustment device of the present invention is as follows: Figure 7 As shown, from Figure 7 It can also be clearly seen from the signal waveform in that when the input signal waveform amplitude remains unchanged, when the load draws a smaller current Io, the output signal waveform amplitude is larger; when the load draws a larger current Io, the output signal waveform amplitude is smaller; thereby, the transistor Q0 is always within the safe operating area, which can accurately and effectively limit the maximum dissipated power of the transistor Q0, greatly improving the reliability of the use of the transistor Q0.

[0073] From the above embodiments, it can also be clearly seen that the device can automatically and accurately control the safe working area of ​​the transistor Q0: 0 ≤ Io ≤ CK*Vce, where K and C are adjustable constant parameters, and the transistor Q0 can be accurately controlled to be always in the safe working area. Therefore, the embodiment of the present invention can adjust the corresponding safe working area range according to the process characteristics of the transistor Q0. For the transistor Q0 with good process characteristics, small on-resistance, and high withstand voltage characteristics, a wider safe working area can be set to meet the requirement that the transistor Q0 can output sufficiently large power; for the transistor Q0 with poor process characteristics, large on-resistance, and low withstand voltage characteristics, a narrower safe working area can be set to limit its output capacity, reduce the maximum dissipated power of the transistor Q0, and improve the reliability of the use of the transistor Q0.

[0074] In summary, the transistor safe operating area adaptive adjustment device and transistor application system provided by the present invention have extremely high adaptive adjustment accuracy, stable performance, simple structure, high reliability and low cost.

[0075] It is to be understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of the present invention, but the present invention is not limited thereto. For those of ordinary skill in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A transistor safe operating area adaptive adjustment device, characterized in that: include: a current sampling unit, a voltage sampling unit, a drive adjustment unit and a transistor unit, wherein the current sampling unit is electrically connected to the voltage sampling unit and the transistor unit respectively, the voltage sampling unit is electrically connected to the transistor unit, and the drive adjustment unit is electrically connected to the voltage sampling unit and the transistor unit respectively, The current sampling unit is used to sample the working current of the transistor unit to obtain the current working current of the transistor unit; The voltage sampling unit is used to collect the voltage difference between the collector and the emitter of the transistor unit under the current working current; The driving adjustment unit is used to adaptively adjust the current working current or the voltage difference between the collector and the emitter according to the load demand to obtain the driving adjustment voltage of the transistor unit; The transistor unit can operate in a safe operating area according to the driving adjustment voltage, and the safe operating area is the real-time operating current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, where Vce represents the voltage difference between the collector and the emitter of the transistor unit at the current operating current, and C and K both represent variable adjustment parameters; The driving adjustment unit comprises: a voltage and current conversion unit and a current driving unit, wherein the voltage and current conversion unit is connected to the voltage sampling unit, and the current driving unit is connected to the voltage and current conversion unit and the transistor unit respectively; The voltage and current conversion unit is used to convert the voltage difference between the collector and the emitter under the current working current into a conversion working current; The current driving unit is used to adaptively adjust the conversion working current or the current working current according to the load demand to obtain the driving adjustment voltage of the transistor unit; The voltage and current conversion unit includes: a first triode, a second triode, a third triode, a fourth triode, a first constant current source and a fourth resistor. The emitter of the first transistor is the input end of the voltage and current conversion unit, and is used to connect the voltage sampling unit. The collector of the first transistor is connected to the positive electrode of the first constant current source. The base of the first transistor is connected to the base of the second transistor. The emitter of the second transistor is connected to a power supply, and the collector of the second transistor is connected to the collector of the third transistor. The emitter of the third transistor is connected to the signal ground, the collector of the third transistor is connected to the base of the third transistor, and the base of the third transistor is connected to the base of the fourth transistor. The collector of the fourth transistor is the output end of the voltage and current conversion unit, and is used to connect to the current driving unit. The emitter of the fourth transistor is connected to the signal ground. The negative electrode of the first constant current source is connected to the signal ground. One end of the fourth resistor is connected to the base of the third transistor, and the other end of the fourth resistor is connected to the signal ground; The current driving unit comprises a second constant current source, a positive electrode of the second constant current source is connected to a power supply, and a negative electrode of the second constant current source is connected to an output end of the voltage and current conversion unit.

2. The transistor safe operating area adaptive adjustment device according to claim 1, characterized in that: The driving adjustment unit is used to adaptively adjust the current working current or the voltage difference between the collector and the emitter according to the load demand to obtain the driving adjustment voltage of the transistor unit, including: When the load requirement is to obtain a current of a preset amplitude, the driving adjustment unit is used to adaptively adjust the voltage difference between the collector and the emitter according to the power consumption of the transistor unit itself, so as to obtain a driving adjustment voltage of the transistor unit; When the load requirement is to obtain a voltage of a preset amplitude, the driving adjustment unit is used to adaptively adjust the current working current according to the power consumption of the transistor unit itself to obtain the driving adjustment voltage of the transistor unit.

3. The transistor safe operating area adaptive adjustment device according to claim 1 or 2, characterized in that: The current sampling unit includes a first resistor, one end of the first resistor is connected to a power supply, and the other end of the first resistor is respectively connected to the voltage sampling unit and the transistor unit.

4. The transistor safe operating area adaptive adjustment device according to claim 1 or 2, characterized in that: The voltage sampling unit includes a second resistor and a third resistor, one end of the second resistor is connected to the current sampling unit, the other end of the second resistor is connected to one end of the third resistor, the other end of the third resistor is connected to the transistor unit, and the connection end of the second resistor and the third resistor is connected to the drive adjustment unit.

5. The transistor safe operating area adaptive adjustment device according to claim 1 or 2, characterized in that: The transistor unit comprises a transistor, a control end of the transistor is connected to the driving adjustment unit, an input end of the transistor is respectively connected to the voltage sampling unit and the current sampling unit, and an output end of the transistor is connected to the voltage sampling unit.

6. A transistor application system, characterized in that: include: A preamplifier module, a load and a transistor safe operating area adaptive adjustment device according to any one of claims 1 to 5, wherein the preamplifier module is connected to a transistor unit of the transistor safe operating area adaptive adjustment device, and the load is connected to an output end of the transistor safe operating area adaptive adjustment device. The preamplifier module is used to amplify the input signal to obtain an amplified signal; The transistor unit in the transistor safe working area adaptive adjustment device is used to amplify the amplified processing signal in the safe working area, and the transistor safe working area adaptive adjustment device can adaptively adjust the driving adjustment voltage of the transistor unit according to the load demand, so that the transistor unit can work in the safe working area, and the safe working area is the real-time working current I of the transistor unit. O Satisfy: 0≤I O ≤CK*Vce, wherein Vce represents the voltage difference between the collector and the emitter of the transistor unit under the current operating current, and C and K both represent variable adjustment parameters.

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