A reference voltage source with a power supply stabilizing unit

Abstract

A reference voltage source with a power supply voltage stabilizing unit, characterized in that the circuit comprises a power supply voltage stabilizing unit and a reference unit; wherein the reference unit generates a reference voltage V bg , and is connected with the power supply voltage stabilizing unit, and outputs the reference voltage V bg to the power supply voltage stabilizing unit; the power supply voltage stabilizing unit is connected with the device voltage end of the operational amplifier in the reference unit, to generate a stabilized voltage V sbrg , and to adjust and stabilize the change of the reference voltage V bg of the reference unit. The present application can provide a more stable stabilized voltage in the case that the load in the later stage changes and affects the power supply voltage, and realizes the stabilization of the reference voltage source.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of integrated circuits, and more particularly, to a reference voltage source with a power supply voltage stabilization unit. BACKGROUND

[0002] At present, as a core module of an analog circuit, a reference voltage source can provide a stable reference voltage that does not change with power supply voltage, process and temperature, and is thus widely used in various integrated circuits. The accuracy of the output voltage of the reference voltage source directly affects the performance of the analog circuit and the chip.

[0003] In the prior art, the output accuracy of the reference voltage source is affected not only by the process manufacturing, but also by the power supply voltage noise. When the power supply voltage fluctuates due to noise, the reference voltage output by the reference voltage source will also change, affecting the accuracy of the reference voltage source. In order to improve the power supply rejection ratio (PSRR) of the reference voltage source circuit, the input pair of the operational amplifier in the reference voltage source circuit can be improved, or the PSRR of the bias current source can be improved, thereby reducing the influence of the power supply voltage noise. However, this method has limited improvement on the PSRR of the reference voltage source.

[0004] Background document CN109947169A discloses a high power supply rejection ratio bandgap reference circuit with a pre-stabilization structure, in which a pre-stabilization circuit is used to form a negative feedback low resistance network, and the reference current generated in the reference current source circuit is multiplexed by mirroring to provide current for the negative feedback low resistance network, thereby suppressing the power supply ripple and effectively improving the power supply rejection ratio. Background document CN211207200U discloses a high power supply rejection ratio reference circuit, in which a MOS transistor is used to realize negative feedback trimming, thereby stabilizing the output voltage.

[0005] However, in the above background technology, the pre-stabilization circuit is included in the start-up loop of the reference circuit, which increases the design risk of stability and makes the circuit structure more complex and redundant. In addition, the feedback node of the above feedback loop is a floating voltage node, which is easily affected by PVT (Process corners, Voltage, Temperature, process corners, voltage and temperature, etc. Circuit influencing factors) parameters, and the robustness of the circuit is poor.

[0006] To solve the above problems, the present application provides a reference voltage source with a power supply voltage stabilization unit. SUMMARY

[0007] In order to solve the problems in the prior art, the reference voltage source with the power voltage stabilizing unit is provided, the power voltage stabilizing unit and the reference unit are connected, the stable voltage V sbrg is adjusted through the negative feedback, and the stable voltage is provided when the load in the latter stage changes, so that the reference voltage is stabilized.

[0008] The application adopts the technical scheme as follows.

[0009] The reference voltage source with the power voltage stabilizing unit, wherein the circuit comprises the power voltage stabilizing unit and the reference unit; the reference unit generates the reference voltage V bg , and is connected with the power voltage stabilizing unit, and outputs the reference voltage V bg to the power voltage stabilizing unit; the power voltage stabilizing unit is connected with the device voltage end of the operational amplifier in the reference unit, and the stable voltage V sbrg generated by the power voltage stabilizing unit is used to adjust and stabilize the change of the reference voltage V bg of the reference unit.

[0010] Preferably, the power voltage stabilizing unit comprises a first mirror unit and a second mirror unit; the first mirror unit is used to receive the reference voltage V bg of the reference unit, adjust the first mirror current based on the change of the reference voltage V bg , and output the first mirror current to the second mirror unit; the second mirror unit is used to adjust the gate voltage of the power tube Mp3 based on the change of the first mirror current and the second mirror current, and adjust the stable voltage V sbrg .

[0011] Preferably, the first mirror unit comprises a first mirror tube Mp1, a second mirror tube Mp2 and a power tube Mp3; the gate and the drain of the first mirror tube Mp1 are connected with the gate of the second mirror tube Mp2 and the output end of the reference voltage V bg of the reference unit; the source of the first mirror tube Mp1, the source of the second mirror tube Mp2 and the drain of the power tube Mp3 are connected with each other, and are all connected with the output end of the stable voltage V sbrg ; the drain of the second mirror tube Mp2 is connected with one end of the reference current source I0 in the second mirror unit, the source of the power tube Mp3 is connected with the power voltage Vdd, and the gate is connected with the drain of the third mirror tube Mp4 and the feedback tube Mn1 in the second mirror unit respectively.

[0012] Preferably, the second mirror unit comprises a feedback tube Mn1, a third mirror tube Mp4, a fourth mirror tube Mp5, a reference current source I0, a current source I5 and a voltage source V1; wherein the source of the feedback tube Mn1 and one end of the reference current source I0 are connected with the drain of the second mirror tube Mp2 in the first mirror unit, the other end of the reference current source I0 is grounded, and the gate of the feedback tube Mn1 is grounded after passing through the voltage source V1, the drain of the feedback tube Mn1 is connected with the drain of the third mirror tube Mp4 and the gate of the power tube Mp3; the gate of the third mirror tube Mp4 is connected with the gate and the drain of the fourth mirror tube Mp5, the source of the third mirror tube Mp4 and the source of the fourth mirror tube Mp5 are connected with the power voltage Vdd; the drain and the gate of the fourth mirror tube Mp5 are grounded after passing through the current source I5.

[0013] Preferably, when the working current of the operational amplifier decreases, the currents I1 and I2 of the mirror tubes in the first mirror unit increase, the source level current of the feedback tube Mn1 decreases, so that the gate voltage of the power tube Mp3 increases and the source-drain current I3 decreases, thereby realizing the stabilization of the regulated voltage V sbrg .

[0014] Preferably, when the working current of the operational amplifier increases, the currents I1 and I2 of the mirror tubes in the first mirror unit decrease, the source level current of the feedback tube Mn1 increases, so that the gate voltage of the power tube Mp3 decreases and the source-drain current I3 increases, thereby realizing the stabilization of the regulated voltage V sbrg .

[0015] Preferably, the regulated voltage output by the regulated unit is V sbrg = V bg + V gs1 ; wherein V gs1 is the gate-drain voltage of the first mirror tube Mp1.

[0016] Preferably, when the switching frequency of the power voltage is less than 100 Hz, the PSRR of the reference voltage source is less than -100 dB.

[0017] The second aspect of the present application relates to a reference voltage adjusting method with a power regulated unit, wherein the method is implemented by using the reference voltage source with the power regulated unit as described in the first aspect of the present application, and the method comprises the following steps: step 1, using the power regulated unit to provide a regulated voltage for the operational amplifier of the reference unit; step 2, outputting the reference voltage V bg of the reference voltage source to the power regulated unit; so that the reference voltage V bg is adjusted to the regulated voltage V sbrg by negative feedback.

[0018] The beneficial effect of the present application is that, compared with the prior art, the reference voltage source with power voltage stabilizing unit in the present application can realize connection with the reference unit by power voltage stabilizing unit, so as to adjust the stabilized voltage V sbrg through negative feedback, and provide more stable stabilized voltage in the case of change of the load in the later stage.

[0019] The present application separates the voltage stabilizing circuit from the starting circuit of the reference source, and after the reference circuit starts and establishes, the voltage stabilizing circuit participates in the work, and there is no risk problem of the starting stability of the voltage stabilizing circuit. In addition, it is important that the voltage participating in the feedback is taken from the stable reference voltage V bg . Therefore, the reference voltage itself is less affected by the changes of temperature, process and the like, so that the stable voltage V sbrg output by the voltage stabilizing circuit will also be a stable voltage changing with V bg in consistency, and the self-consistency of the circuit is better. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a circuit structure schematic diagram of the reference voltage source with power voltage stabilizing unit in the present application;

[0021] Figure 2 It is a circuit structure schematic diagram of the power voltage stabilizing unit in the reference voltage source with power voltage stabilizing unit in the present application;

[0022] Figure 3 It is a power voltage rejection ratio curve diagram of the output voltage of the reference voltage source with power voltage stabilizing unit in the present application;

[0023] Figure 4 It is a step schematic diagram of the voltage stabilizing voltage adjusting method in the present application. DETAILED DESCRIPTION

[0024] The present application will be further described below in combination with the drawings. The following examples are only used to more clearly illustrate the technical solutions of the present application, and cannot be used to limit the protection scope of the present application.

[0025] Figure 1 It is a circuit structure schematic diagram of the reference voltage source with power voltage stabilizing unit in the present application. As shown in Figure 1 , in the present application, the reference voltage source is composed of a general zero-temperature-coefficient bandgap reference circuit. In order to prevent the power voltage from affecting the operational amplifier, so that the output signal of the operational amplifier, i.e. the reference voltage V bg is not stable enough, a power voltage stabilizing unit is provided. The power voltage stabilizing unit is shown as sub-regulator in Figure 1 , which prevents the power voltage from directly supplying power to the operational amplifier, but uses the power voltage stabilizing unit to provide stable stabilized voltage Vsbrg Thus, the control of the operational amplifier is realized.

[0026] Figure 2 The figure is a schematic diagram of the circuit structure of the power supply voltage stabilizing unit in the reference voltage source with the power supply voltage stabilizing unit. Figure 2 As shown in the figure, the reference voltage source with the power supply voltage stabilizing unit comprises the power supply voltage stabilizing unit and the reference unit; wherein the reference unit generates the reference voltage V bg and is connected with the power supply voltage stabilizing unit, and outputs the reference voltage V bg to the power supply voltage stabilizing unit; the power supply voltage stabilizing unit is connected with the device voltage end of the operational amplifier in the reference unit, and generates the stabilized voltage V sbrg for the reference unit. bg The change of the reference voltage V

[0027] In the present application, in order to make the power supply voltage stabilizing unit have better PSRR characteristics, the power supply voltage stabilizing unit is added to the reference voltage source circuit.

[0028] Different from most feedback loops in the prior art, the power supply voltage stabilizing unit in the present application can be directly connected with the subsequent load, and in the case that the subsequent load changes, the rapid feedback and adjustment of the reference voltage are realized, and the time delay generated after the reference voltage is output through the operational amplifier is prevented.

[0029] In addition, importantly, the voltage participating in the feedback is taken from the stable reference voltage V bg , and the reference voltage itself is less affected by the changes of temperature, process, etc., so that the stable voltage V sbrg output by the voltage stabilizing circuit will also be a stable voltage changing with V bg , and the self-consistency of the circuit is better.

[0030] Preferably, the power supply voltage stabilizing unit comprises a first mirror unit and a second mirror unit; wherein the first mirror unit is used for receiving the reference voltage V bg of the reference unit, and adjusting the first mirror current based on the change of the reference voltage V bg , and outputting the first mirror current to the second mirror unit; the second mirror unit is used for adjusting the gate voltage of the power tube Mp3 based on the change of the first mirror current and the second mirror current, and adjusting the stabilized voltage V sbrg .

[0031] It can be understood that the power supply voltage stabilizing unit in the present application can be divided into the first mirror unit and the second mirror unit. The first mirror unit is mainly used for receiving the reference voltage V bg , and adjusting the first mirror current based on the change of the reference voltage V bgThe first mirror unit can sense the change of the reference voltage and the load current and transfer the change to the second mirror unit by mirroring. The second mirror unit can realize the reverse regulation of the gate voltage of the power tube Mp3 because of the constant current source and the voltage source with relatively unchanged output.

[0032] Preferably, the first mirror unit comprises a first mirror tube Mp1, a second mirror tube Mp2 and a power tube Mp3. The gate and the drain of the first mirror tube Mp1 are connected to the gate and the reference voltage V bg of the reference unit respectively. The source of the first mirror tube Mp1, the source of the second mirror tube Mp2 and the drain of the power tube Mp3 are connected to each other and to the output terminal of the voltage regulator V sbrg . The drain of the second mirror tube Mp2 is connected to one end of the reference current source I0 in the second mirror unit. The source of the power tube Mp3 is connected to the power voltage Vdd. The gate of the power tube Mp3 is connected to the drain of the third mirror tube Mp4 and the feedback tube Mn1 in the second mirror unit respectively.

[0033] Preferably, the second mirror unit comprises a feedback tube Mn1, a third mirror tube Mp4, a fourth mirror tube Mp5, a reference source I0, a current source I5 and a voltage source V1. The source of the feedback tube Mn1 and one end of the reference current source I0 are connected to the drain of the second mirror tube Mp2 in the first mirror unit. The other end of the reference current source I0 is grounded. The gate of the feedback tube Mn1 is connected to the voltage source V1 and then grounded. The drain of the feedback tube Mn1 is connected to the drain of the third mirror tube Mp4 and the gate of the power tube Mp3 respectively. The gate of the third mirror tube Mp4 is connected to the gate and the drain of the fourth mirror tube Mp5 respectively. The source of the third mirror tube Mp4 and the source of the fourth mirror tube Mp5 are connected to the power voltage Vdd. The drain and the gate of the fourth mirror tube Mp5 are connected to the current source I5 and then grounded.

[0034] For the circuit, a static working point can be established after the power voltage Vdd is powered on. At the static working point, the size of the source-drain current I3 flowing through the power tube Mp3 is the sum of the working current Iload flowing through the operational amplifier, the current I1 flowing through the source-drain of the first mirror tube Mp1 and the current I2 flowing through the source-drain of the second mirror tube Mp2. On the other hand, at the static working point, the size of the current I0 of the reference current source, which can be a constant current source in the present application, is equal to the sum of the source-drain current I4 of the third mirror tube Mp4 and the source-drain current I2 of the second mirror tube Mp2. When the current is constant, the size of the output voltage V sbrg is controlled by the reference voltage V bg . This part will be described in detail later.

[0035] It can be understood that, in the present application, when the operational amplifier current I load decreases, the mirror tube current I1 and I2 in the first mirror unit increases, the source-drain current of the feedback tube Mn1 decreases, the gate voltage of the power tube Mp3 increases, and the source-drain current I3 decreases, thereby stabilizing the regulated voltage V sbrg .

[0036] Specifically, when the load at the back end of the circuit changes, the regulated voltage V sbrg can still maintain a relatively stable output. When the operational amplifier current Iload decreases, the current of the power tube Mp3 is controlled by its gate voltage and does not immediately change. At this time, the source-drain currents of the mirror tubes Mp1 and Mp2 connected to the output end of the operational amplifier, i.e., the reference voltage V bg , are simultaneously affected by the current I3 and the operational amplifier current Iload and will increase with the decrease of the operational amplifier current, and the increase is equal to the decrease of the operational amplifier current.

[0037] At this time, for the current source I0, the value of the current I2 of the branch connected thereto increases, which will cause the current of the feedback tube Mn1 to decrease, and the decrease is equal to the decrease of the operational amplifier current.

[0038] Since the gate of the Mn1 tube is connected to a direct current voltage and receives the input change caused by the joint action of I0 and I2 at the source and generates an output at the drain, this implementation as a common gate causes the voltage at the gate of Mp3 to change with the change of the source current.

[0039] When the source current of Mn1 decreases, the gate driving voltage of Mp3 in the branch composed of the mirror tube Mp4, the feedback tube Mn1, and the reference current source I0 increases, i.e., the voltage at the VG point increases, and the source-drain current I3 of Mp3 decreases. Figure 2

[0040] It can be seen that, with the action of the feedback path Mp2, Mn1, and Mp3, when the reference voltage decreases or the operational amplifier current Iload decreases, the drain output current of the Mp3 tube in the present application also decreases. This characteristic causes the regulated voltage V sbrg to remain stable, thereby stabilizing the output of the operational amplifier. At the same time, since this feedback loop only passes through three MOS tubes, the time delay caused by the operational amplifier is greatly reduced, and the response speed is fast.

[0041] Preferably, when the operational amplifier current I load increases, the source current of the feedback tube Mn1 increases, the gate voltage of the power tube Mp3 decreases, and the source-drain current I3 increases, thereby stabilizing the regulated voltage V sbrg . ​

[0042] Understandably, the method in this invention is also applicable to situations where the load current increases, causing a change in the current amplitude in the opposite direction in the feedback loop of the circuit, thereby ensuring the regulated voltage V. sbrg Stability.

[0043] Preferably, the regulated voltage output by the voltage regulator unit is V. sbrg =V bg +V gs1 Among them, V gs1 This is the gate-drain voltage of the first image transistor Mp1.

[0044] In this invention, the value of the regulated voltage can be determined based on the reference voltage output by the operational amplifier. Since the regulated voltage is separated from the operational amplifier output only by the gate-source terminals of the first and second image transistors, V0 = ... sbrg =V bg +V gs1 .

[0045] Figure 3 This is a schematic diagram of the power supply voltage rejection ratio curve of the output voltage of a reference voltage source with a power supply regulation unit according to the present invention. Figure 3 As shown, the power supply voltage rejection ratio (PSRR) of the reference voltage source without the power supply voltage regulator unit of this invention varies with different power supply voltage frequencies, as represented by the dashed line in the figure. The PSRR exponent of the reference voltage source of this invention using the power supply voltage regulator unit is shown by the solid line in the figure. When the frequency range of the power supply voltage is within 10... -1 Up to 10 6 Within the specified range, a significant improvement in PSRR by the power supply regulator unit can be observed. When the power supply voltage frequency is within 10... -1 Up to 10 2 Within this range, the PSRR remains constant at around -120.0 dB, less than -100.0 dB. This demonstrates that the reference voltage source employing the power supply regulation unit of this invention exhibits excellent power supply voltage rejection ratio, providing a reliable and accurate reference voltage for subsequent circuits.

[0046] Figure 4 This is a schematic diagram illustrating the steps of a voltage regulation method according to the present invention. Figure 4 As shown, the second aspect of the present invention relates to a reference voltage stabilization adjustment method as described in the first aspect of the present invention. The method includes steps 1 and 2.

[0047] Specifically, step 1 involves using a power supply voltage regulator to provide a regulated voltage to the operational amplifier of the reference unit; step 2 involves converting the reference voltage V from the reference voltage source... bg The output is sent to the power supply regulation unit so that the reference voltage V bg The regulated voltage V is adjusted via negative feedback. sbrg.

[0048] The beneficial effect of the present application is that, compared with the prior art, the reference voltage source with the power stabilizing unit in the present application can be connected with the reference unit by using the power stabilizing unit to re-adjust the stabilized voltage, thereby providing more stable stabilized voltage in the case of load change, and further providing stable reference voltage.

[0049] The applicant of the present application has made detailed description and illustration of the embodiments of the present application in combination with the drawings of the specification, but those skilled in the art should understand that the above embodiments are only preferred embodiments of the present application, and the detailed description is only to help the reader better understand the spirit of the present application, and is not a limitation on the protection scope of the present application, on the contrary, any improvement or modification based on the spirit of the present application should fall within the protection scope of the present application.

Claims

1. A reference voltage source with power supply regulation unit, characterized in that: the reference voltage source comprises a power supply regulation unit and a reference unit; wherein, The reference unit generates a reference voltage V bg connected with the power supply voltage stabilizing unit and outputs the reference voltage V bg to the power supply voltage stabilizing unit. The power supply voltage stabilization unit is connected with the device voltage terminal of the operational amplifier in the reference unit to generate a stabilized voltage V sbrg The change of the reference voltage V bg of the reference unit is adjusted and stabilized. the power supply regulation unit comprises a first mirror unit and a second mirror unit; the first mirror unit comprises a first mirror transistor Mp1, a second mirror transistor Mp2, and a power transistor Mp3; the second mirror unit comprises a feedback transistor Mn1, a third mirror transistor Mp4, a fourth mirror transistor Mp5, a reference current source I0, a current source I5, and a voltage source V1; The gate and the drain of the first mirror tube Mp1 are connected with the gate and the reference voltage V of the reference unit of the second mirror tube Mp2 bg Output terminal connection The source of the first mirror tube Mp1, the source of the second mirror tube Mp2 and the drain of the power tube Mp3 are connected to each other and are connected to the output end of the voltage stabilizing voltage V sbrg ​ the drain of the second mirror transistor Mp2 is connected to one end of the reference current source I0 in the second mirror unit, the source of the power transistor Mp3 is connected to a power supply voltage Vdd, and the gate is connected to the drain of the third mirror transistor Mp4 and the feedback transistor Mn1 in the second mirror unit, respectively; the source of the feedback transistor Mn1 and one end of the reference current source I0 are both connected to the drain of the second mirror transistor Mp2 in the first mirror unit, the other end of the reference current source I0 is grounded, and the gate of the feedback transistor Mn1 is grounded through the voltage source V1, the drain of the feedback transistor Mn1 is connected to the drain of the third mirror transistor Mp4 and the gate of the power transistor Mp3, respectively; the gate of the third mirror transistor Mp4 is connected to the gate and the drain of the fourth mirror transistor Mp5, respectively, and the source of the third mirror transistor Mp4 and the source of the fourth mirror transistor Mp5 are both connected to the power supply voltage Vdd; the drain and the gate of the fourth mirror transistor Mp5 are grounded through the current source I5. 2.The reference voltage source with power supply regulation unit according to claim 1, characterized in that: The first mirror unit is configured to receive a reference voltage V bg from the reference unit, adjust a first mirror current based on a change in the reference voltage V bg , and output the first mirror current to the second mirror unit. The second mirror unit is configured to jointly adjust the gate voltage of the power transistor Mp3 based on the change of the first mirror current and the second mirror current, so as to adjust the voltage V sbrg . 3.The reference voltage source with power supply regulation unit according to claim 1, characterized in that: When the working current of the operational amplifier is reduced, the currents I1 and I2 of the mirror tubes in the first mirror unit are increased, the source-level current of the feedback tube Mn1 is reduced, the gate voltage of the power tube Mp3 is raised, and the source-drain current I3 is reduced, thereby stabilizing the regulated voltage V sbrg . 4.The reference voltage source with power supply regulation unit according to claim 1, characterized in that: When the working current of the operational amplifier is increased, the currents I1 and I2 of the mirror tubes in the first mirror unit are reduced, the source-level current of the feedback tube Mn1 is increased, the gate voltage of the power tube Mp3 is reduced, the source-drain current I3 is increased, and the stability of the stabilized voltage V sbrg is realized. 5.The reference voltage source with power supply regulation unit according to claim 3 or 4, characterized in that: The regulated voltage output by the regulated unit is V sbrg = V bg + V gs1 ; wherein, V gs1 Gate leakage voltage for the first mirror tube Mp1. 6.The reference voltage source with power supply regulation unit according to claim 5, characterized in that: when the switching frequency of the power supply voltage is less than 100 Hz, the PSRR of the reference voltage source is less than -100 dB.

7. A reference voltage adjustment method with a power supply regulator unit, characterized by, The method is implemented by using the reference voltage source with power supply regulation unit according to any one of claims 1-6, and the method comprises the following steps: Step 1, a power supply stabilizing unit is used to provide a stabilized voltage V sbrg for the operational amplifier of the reference unit Step 2, the reference voltage V bg to the power supply voltage stabilization unit, so that the reference voltage V bg The regulated voltage V sbrg is adjusted by negative feedback.

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