Linear voltage regulators, chips and electronic devices

Abstract

This invention provides a linear voltage regulator, chip, and electronic device, comprising: a voltage regulation module that receives an input power supply and converts the input power supply into a stable output power supply by adjusting the power transistor in the voltage regulation module, wherein the output power supply is less than the input power supply; and a power supply voltage detection module that is connected to the input power supply, detects the input power supply, and outputs a shutdown control signal for the voltage regulation module when the input power supply fluctuates based on the detection result. The linear voltage regulator, chip, and electronic device of this invention introduces a power supply detection module. When the input power supply fluctuates rapidly, the gate voltage of the power transistor is pulled down to turn off the power transistor, cutting off the transmission path from the input power supply to the output power supply, thereby protecting the electrical circuit. After the input power supply stabilizes, the power transistor is turned back on to supply power to the electrical circuit. This invention can effectively reduce the risk of damage to the electrical circuit and improve the safety of the chip and electronic device.

Description

Technical Field

[0001] This invention relates to the field of power supplies, and in particular to a linear voltage regulator, chip, and electronic device. Background Technology

[0002] Electronic devices generally obtain power through two means: one is AC mains power after rectification, and the other is battery power. Regardless of the source, the voltage of the power supply will vary significantly during operation. To ensure power stability, a voltage regulator is required. However, if the input power of the voltage regulator experiences large fluctuations within a short period, its output power will still fluctuate. When the power supply becomes abnormally high, it can easily cause subsequent circuits to break down, resulting in chip damage.

[0003] Therefore, how to avoid the impact of input power supply jitter on the output power of the voltage regulator and protect the power circuit has become one of the problems that urgently need to be solved by those skilled in the art.

[0004] It should be noted that the above description of the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of the present invention and facilitating understanding by those skilled in the art. It should not be assumed that the above technical solutions are known to those skilled in the art simply because they have been described in the background section of this invention. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a linear voltage regulator, chip, and electronic device to solve the problem that input power jitter may damage the electrical circuit in the prior art.

[0006] To achieve the above and other related objectives, the present invention provides a linear voltage regulator, the linear voltage regulator comprising at least:

[0007] Voltage regulation module and power supply voltage detection module;

[0008] The voltage regulation module receives the input power and converts the input power into a stable output power by adjusting the power transistor in the voltage regulation module, and the output power is less than the input power.

[0009] The power supply voltage detection module is connected to the input power supply, detects the input power supply, and outputs a shutdown control signal for the voltage regulation module when the input power supply fluctuates based on the detection result.

[0010] Optionally, the voltage regulation module includes a power transistor, a feedback unit, and an error amplifier;

[0011] The first end of the power transistor is connected to the input power supply, the second end is grounded via the feedback unit, and the control end is connected to the output end of the error amplifier and the power supply voltage detection module; the second end of the power transistor outputs the output power supply.

[0012] The first input terminal of the error amplifier is connected to the feedback voltage output by the feedback unit, and the second input terminal is connected to the reference voltage. The control signal of the power transistor is generated based on the difference between the feedback voltage and the reference voltage.

[0013] Alternatively, the power transistor is an NMOS transistor.

[0014] Alternatively, the feedback unit includes a first resistor and a second resistor connected in series between the second terminal of the power transistor and ground; the connection node between the first resistor and the second resistor serves as the output terminal of the feedback unit.

[0015] Alternatively, the non-inverting input of the error amplifier is connected to the reference voltage, the inverting input is connected to the output of the feedback unit, and the output is connected to the control terminal of the power transistor.

[0016] Alternatively, the power supply voltage detection module includes a capacitor, a first transistor, a second transistor, and a Zener diode;

[0017] One end of the capacitor is connected to the input power supply, and the other end is connected to the cathode of the Zener diode; the anode of the Zener diode is grounded.

[0018] The first terminal of the first transistor is connected to the cathode of the Zener diode, the second terminal is grounded, and the control terminal receives the bias voltage to provide pull-down current.

[0019] The first terminal of the second transistor is connected to the control terminal of the power transistor, and the second terminal is grounded. The control terminal is connected to the cathode of the Zener diode. When the input power supply is stable, the second transistor is turned off, and when the input power supply fluctuates, the second transistor is turned on to turn off the power transistor.

[0020] Alternatively, the first transistor is an NMOS transistor, and the second transistor is an NMOS transistor.

[0021] To achieve the above and other related objectives, the present invention also provides a chip, the chip comprising at least: the above-mentioned linear voltage regulator and a power supply circuit; the linear voltage regulator supplies power to the power supply circuit.

[0022] Optionally, the chip further includes a power module that provides input power to the linear voltage regulator; the power module is a rectifier circuit or a battery.

[0023] To achieve the above and other related objectives, the present invention also provides an electronic device, which includes at least the above-described linear voltage regulator.

[0024] As described above, the linear voltage regulator, chip, and electronic device of the present invention have the following beneficial effects:

[0025] The linear voltage regulator, chip, and electronic device of this invention incorporate a power detection module. When rapid fluctuations occur in the input power supply, the gate voltage of the power transistor is pulled down to shut it down, cutting off the transmission path from the input power supply to the output power supply and protecting the electrical circuit. After the input power supply stabilizes, the power transistor is turned back on to supply power to the electrical circuit. This invention effectively reduces the risk of damage to the electrical circuit and improves the safety of the chip and electronic device. Attached Figure Description

[0026] Figure 1 The diagram shown is a structural schematic of a low-dropout linear regulator.

[0027] Figure 2 The diagram shown is a block diagram of the linear voltage regulator of the present invention.

[0028] Figure 3 The diagram shown is a schematic representation of the linear voltage regulator of the present invention.

[0029] Figure 4 The diagram shows a simulated waveform of a linear regulated power supply without a power detection circuit.

[0030] Figure 5 The diagram shows a simulation waveform of the linear voltage regulator with added power detection circuit of the present invention.

[0031] Component designation explanation

[0032] 1-Low dropout linear regulator; 2-Linear voltage regulator; 21-Voltage regulation module; 211-Feedback unit; 212-Error amplifier; 22-Power supply voltage detection module. Detailed Implementation

[0033] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0034] Please see Figures 1-5It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0035] like Figure 1 The diagram shows a low-dropout linear regulator 1, which converts the battery voltage V... BAT Converted to supply voltage V CC Among them, the feedback module controls the supply voltage V. CC Sample the voltage and return the feedback voltage V. F The voltage is supplied to the error amplifier; the error amplifier calculates the feedback voltage V. F With reference voltage V REF The difference is calculated, and the gate voltage of the power transistor is adjusted based on this difference. Based on the "virtual short" at the input of the error amplifier, the power transistor is continuously adjusted to stabilize the feedback voltage VF at the reference voltage V. REF Thus, a stable supply voltage V is obtained. CC By adjusting the feedback voltage V F With supply voltage V CC The ratio of these values ​​can be used to obtain a suitable supply voltage V. CC .

[0036] When the battery voltage V BAT When large fluctuations occur within a short period of time, the limited bandwidth of the low-dropout linear regulator 1 causes the supply voltage V to... CC Follows battery voltage V for a short time BAT Increase, in extreme cases, the supply voltage V CC It may increase by more than double; at this time, the supply voltage V CC It may approach or exceed the maximum withstand voltage of the low-voltage circuits that supply power, increasing the risk of chip breakdown due to overvoltage.

[0037] To address the aforementioned issues, this invention provides a linear voltage regulator that shuts off when the input power supply experiences significant fluctuations within a short period, preventing the output power supply from rising and thus reducing the risk of damage to subsequent power circuits (low voltage).

[0038] like Figure 2 and Figure 3 As shown, the linear voltage regulator 2 of the present invention includes:

[0039] Voltage regulation module 21 and power supply voltage detection module 22.

[0040] like Figure 2As shown, the voltage regulation module 21 receives the input power Vin (provided by a battery or rectifier module as an example), and converts the input power Vin into a stable output power Vout by adjusting the power transistor Q in the voltage regulation module 21; the output power Vout is less than the input power Vin.

[0041] Specifically, the input power supply of the voltage regulator module 21 has a certain voltage difference compared to the output power supply. In this embodiment, this voltage difference is the minimum voltage difference required for the voltage regulator module 21 to operate normally and maintain a stable output. Any circuit structure capable of achieving low-dropout linear voltage regulation is applicable to the voltage regulator module 21 of this invention. For example... Figure 2 and Figure 3 As shown in the example, the voltage regulation module 21 includes a power transistor Q, a feedback unit 211, and an error amplifier 212. The first terminal of the power transistor Q is connected to the input power supply Vin, the second terminal is connected to the feedback unit 211, and the control terminal is connected to the output terminal of the error amplifier 212. The power transistor Q is controlled based on the output signal of the error amplifier 212, thereby adjusting the output voltage of the power transistor Q to achieve voltage regulation. In this example, the power transistor Q is implemented using an NMOS transistor; therefore, the first terminal of the power transistor Q is the drain, the second terminal is the source, and the control terminal is the gate. In practical applications, the power transistor Q can be any power device suitable for the application of this invention, including but not limited to PNP transistors, NPN transistors, and PMOS transistors, which will not be elaborated here. One end of the feedback unit 211 is connected to the second terminal of the power transistor Q, and the other end is grounded; it samples the output power supply Vout and outputs a feedback voltage VF. In this embodiment, the feedback unit 211 includes a first resistor R1 and a second resistor R2 connected in series. The first end of the first resistor R1 is connected to the second end of the power transistor Q, and the second end is connected to the first end of the second resistor R2 and serves as the output terminal of the feedback unit 211. The second end of the second resistor R2 is grounded. The first resistor R1 and the second resistor R2 can be a single resistor, or multiple resistors connected in series, parallel, or a series-parallel structure. In practical use, any circuit structure that can sample the output power supply Vout and generate a corresponding feedback voltage is applicable to this invention, and will not be described in detail here. The first input terminal of the error amplifier 212 is connected to the feedback voltage VF, and the second input terminal is connected to the reference voltage V. REF The control signal for the power transistor Q is generated based on the difference between the feedback voltage VF and the reference voltage VREF. As an example, the non-inverting input of the error amplifier 212 is connected to the reference voltage VF. REF The inverting input is connected to the feedback voltage V. F The output terminal is connected to the control terminal of the power transistor Q. In actual use, the correspondence between the input signal and the polarity of the input terminal of the error amplifier 212 can be interchanged. The polarity of each node can be adjusted by devices such as inverters to achieve the logic of this invention. It will not be elaborated here.

[0042] Specifically, the output power supply Vout should be stable at a preset voltage value. When the output power supply Vout increases, the feedback voltage V... F As the voltage increases and becomes greater than the reference voltage VREF, the drive current output by the error amplifier 212 decreases, the voltage drop across the power transistor Q increases, and consequently, the output power supply Vout decreases. When the output power supply Vout decreases, the feedback voltage VF decreases accordingly and becomes less than the reference voltage V. REF As the drive current of the error amplifier 212 increases, the voltage drop of the power transistor Q decreases, which in turn increases the output power supply Vout; this cycle repeats until a stable output is obtained.

[0043] like Figure 2 As shown, the power supply voltage detection module 22 is connected to the input power supply Vin, detects the input power supply Vin, and outputs a shutdown control signal to the voltage regulation module 21 when the input power supply Vin fluctuates based on the detection result.

[0044] Specifically, the power supply voltage detection module 22 determines whether the input power supply Vin is fluctuating by detecting the amplitude of the input power supply Vin. The judgment threshold can be set according to actual needs (i.e., when the amplitude of the input power supply Vin is greater than the set value and the difference is greater than the threshold, it is determined that there is a fluctuating risk of damaging the subsequent power circuit; when the difference does not reach the threshold, it is determined that there is no fluctuating risk of damaging the subsequent power circuit). When it is determined that the input power supply Vin is fluctuating, a turn-off control signal for the power transistor Q is generated, thereby turning off the power transistor Q; when it is determined that the input power supply Vin is not fluctuating, there is no output signal, which does not affect the control of the power transistor Q by the error amplifier 212, and the voltage regulation module 21 works normally and outputs a stable output power supply Vout. Any circuit structure that can achieve the above functions is applicable to this invention.

[0045] More specifically, such as Figure 3As shown in the example, the power supply voltage detection module 22 includes a capacitor C, a first transistor M1, a second transistor M2, and a Zener diode Z. One end of the capacitor C is connected to the input power supply Vin, and the other end is connected to the cathode of the Zener diode Z; the anode of the Zener diode Z is grounded. The capacitor C and the Zener diode Z are used to sense the increase in the input power supply Vin over a short period of time. The first end of the first transistor M1 is connected to the cathode of the Zener diode Z, and the second end is grounded. Its control terminal receives the bias voltage Vb and is used to provide pull-down current. The first end of the second transistor M2 is connected to the control terminal of the power transistor Q, and the second end is grounded. Its control terminal is connected to the cathode of the Zener diode Z. That is, the control of the second transistor M2 is achieved based on the voltage change sensed by the capacitor C and the pull-down current provided by the first transistor M1 (the Zener diode Z is used to clamp the control terminal of the power transistor Q). In this example, both the first transistor M1 and the second transistor M2 are implemented using NMOS transistors. In actual use, any transistor that can achieve the function of the power supply voltage detection module 22 of this invention can be used, including but not limited to PMOS transistors, which will not be described in detail here.

[0046] It should be noted that, as an example, the power transistor Q of the present invention is fabricated using a high-voltage process. In actual use, the power transistor Q, the first transistor M1, and the second transistor M2 can be configured according to actual needs and are not limited to this embodiment.

[0047] More specifically, in this embodiment, the first transistor M1 is controlled by the bias voltage Vb, providing a pull-down current. When the input power supply Vin is stable (no jitter that could damage subsequent circuits occurs), the voltage across capacitor C remains unchanged. The pull-down current provided by the first transistor M1 pulls the gate of the second transistor M2 to ground, turning off the second transistor M2. No current flows through the second transistor M2, meaning the power supply voltage detection module 22 has no output signal, and the power transistor Q is controlled by the output signal of the error amplifier 212. When the input power supply Vin increases rapidly (a jitter that could damage subsequent circuits occurs), the input power supply Vin charges capacitor C. The faster the input power supply Vin changes, the larger the charging current to capacitor C (at this time, the pull-down current is much smaller than the charging current of capacitor C). More charge is transferred to the gate of the second transistor M2 through capacitor C, causing the gate voltage V of the second transistor M2 to increase. G2 The voltage rises rapidly within a short period of time, and the second transistor M2 is turned on; the second transistor M2 increases the gate voltage V of the power transistor Q. G1 When pulled down to ground, the power transistor Q is turned off, and the output power supply Vout drops to 0, thus protecting the subsequent power circuits. After the input power supply Vin stabilizes, under the action of the first transistor M1, the gate voltage of the second transistor M2 is pulled down again, the voltage regulation module 21 restarts, and the output power supply Vout rises to the preset value.

[0048] like Figure 4The figure shows the simulated waveform of linear regulated source 2 without a power detection circuit. As can be seen from the figure, the input power supply Vin changes rapidly at 500μs, rising from 13.5 V to 40 V within 0.1μs; at the same time, the output power supply Vout changes accordingly, increasing by 2.2 V. Figure 5 The figure shows the simulation waveform of the linear regulator 2 with added power detection circuit. It can be seen from the figure that the input power supply Vin rises from 13.5V to 40V within 0.1μs. Through the effect of capacitor C, the gate voltage V of the second transistor M2 is increased. G2 When the voltage of the input power supply Vout increases, the gate voltage of the power transistor Q is pulled down by the second transistor M2, thereby turning off the power transistor Q. At this time, the output power supply Vout becomes 0, and after the input power supply Vin stabilizes, the output power supply Vout returns to its original value.

[0049] This invention also provides a chip, comprising at least: a linear voltage regulator 2 and a power supply circuit; the linear voltage regulator 2 supplies power to the power supply circuit. As an example, the chip further includes a power module that provides input power Vin to the linear voltage regulator 2; the power module includes, but is not limited to, a rectifier circuit or a battery. In the chip of this invention, when the input power Vin experiences rapid fluctuations, the linear voltage regulator 2 is shut down, preventing the output power Vout (the power supply to the power supply circuit) from rising, reducing the risk of damage to the power supply circuit, and improving chip safety.

[0050] The present invention also provides an electronic device, which includes at least the linear voltage regulator 2 of the present invention. The electronic device includes, but is not limited to, consumer electronics, industrial control electronics, and communication electronics, etc., which will not be elaborated upon here.

[0051] In summary, this invention provides a linear voltage regulator, chip, and electronic device, comprising: a voltage regulation module and a power supply voltage detection module; the voltage regulation module receives an input power supply and converts the input power supply into a stable output power supply by adjusting the power transistor in the voltage regulation module, wherein the output power supply is less than the input power supply; the power supply voltage detection module is connected to the input power supply, detects the input power supply, and outputs a shutdown control signal for the voltage regulation module when the input power supply fluctuates based on the detection result. The linear voltage regulator, chip, and electronic device of this invention introduces a power supply detection module, which pulls down the gate voltage of the power transistor to turn off the power transistor when the input power supply fluctuates rapidly, cutting off the transmission path from the input power supply to the output power supply, thereby protecting the electrical circuit; and after the input power supply returns to stability, it turns the power transistor back on to supply power to the electrical circuit. This invention can effectively reduce the risk of damage to the electrical circuit and improve the safety of the chip and electronic device. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0052] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A linear voltage regulator, characterized in that, The linear voltage regulator includes at least: Voltage regulation module and power supply voltage detection module; The voltage regulation module receives the input power and converts the input power into a stable output power by adjusting the power transistor in the voltage regulation module, and the output power is less than the input power. The power supply voltage detection module is connected to the input power supply, detects the input power supply, and outputs a shutdown control signal for the voltage regulation module when the input power supply fluctuates based on the detection result. The power supply voltage detection module includes a capacitor, a first transistor, a second transistor, and a Zener diode. One end of the capacitor is connected to the input power supply, and the other end is connected to the cathode of the Zener diode; the anode of the Zener diode is grounded. The first terminal of the first transistor is connected to the cathode of the Zener diode, the second terminal is grounded, and the control terminal receives the bias voltage to provide pull-down current. The first terminal of the second transistor is connected to the control terminal of the power transistor, and the second terminal is grounded. The control terminal is connected to the cathode of the Zener diode. When the input power supply is stable, the second transistor is turned off, and when the input power supply fluctuates, the second transistor is turned on to turn off the power transistor.

2. The linear voltage regulator according to claim 1, characterized in that: The voltage regulation module includes a power transistor, a feedback unit, and an error amplifier; The first end of the power transistor is connected to the input power supply, the second end is grounded via the feedback unit, and the control end is connected to the output end of the error amplifier and the power supply voltage detection module; the second end of the power transistor outputs the output power supply. The first input terminal of the error amplifier is connected to the feedback voltage output by the feedback unit, and the second input terminal is connected to the reference voltage. The control signal of the power transistor is generated based on the difference between the feedback voltage and the reference voltage.

3. The linear voltage regulator according to claim 2, characterized in that: The power transistor is an NMOS transistor.

4. The linear voltage regulator according to claim 2, characterized in that: The feedback unit includes a first resistor and a second resistor connected in series between the second terminal of the power transistor and ground; the connection node between the first resistor and the second resistor serves as the output terminal of the feedback unit.

5. The linear voltage regulator according to claim 2, characterized in that: The non-inverting input of the error amplifier is connected to the reference voltage, the inverting input is connected to the output of the feedback unit, and the output is connected to the control terminal of the power transistor.

6. The linear voltage regulator according to claim 1, characterized in that: The first transistor is an NMOS transistor, and the second transistor is an NMOS transistor.

7. A chip, characterized in that, The chip includes at least: a linear voltage regulator and a power supply circuit as described in any one of claims 1-6; the linear voltage regulator supplies power to the power supply circuit.

8. The chip according to claim 7, characterized in that: The chip also includes a power module, which provides input power to the linear voltage regulator; the power module is a rectifier circuit or a battery.

9. An electronic device, characterized in that, The electronic device includes at least one of the linear voltage regulators as described in any one of claims 1-6.

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