CN210351014U - Low dropout voltage stabilizing circuit - Google Patents
Low dropout voltage stabilizing circuit Download PDFInfo
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- CN210351014U CN210351014U CN201920738134.1U CN201920738134U CN210351014U CN 210351014 U CN210351014 U CN 210351014U CN 201920738134 U CN201920738134 U CN 201920738134U CN 210351014 U CN210351014 U CN 210351014U
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Abstract
The utility model discloses a low dropout voltage stabilizing circuit, including Boost circuit unit, bias current circuit and power voltage stabilizing circuit, Boost circuit unit respectively with the bias current circuit and power voltage stabilizing circuit connects. The utility model discloses can reduce and reduce input/output pressure differential under the prerequisite of guaranteeing output steady voltage precision, be applicable to the wide circuit of input power supply scope, and require at the low pressure during operation, can reach the effect that input/output pressure differential is close to zero.
Description
Technical Field
The utility model relates to a voltage stabilizing circuit field especially relates to a low dropout voltage stabilizing circuit.
Background
In electronic devices, the power supply voltage may vary in a wide range, for example, a lithium ion battery in a portable device can provide 4.2 volts when fully charged, and can only provide 2.3 volts after discharging, which is a wide range of variations. However, the working circuit of the electronic device usually needs a stable power voltage, so a Low Dropout Regulator (LDO) is usually added at the input end of the power supply at present, and since the LDO has a set regulated voltage, the LDO first converts the actual power voltage into the set regulated voltage and then provides the converted regulated voltage to the working circuit, thereby ensuring that the voltage provided to the working circuit by the LDO is always stable when the input power voltage of the electronic device changes.
However, in the research and practice process of the prior art, the inventor of the present invention finds that the input voltage difference of the present low-voltage-difference voltage stabilizing circuit is still large, when the input and output required voltage difference is lower than 1V, the voltage stabilizing effect cannot be realized, and the applicable input voltage range is small; in addition, in the prior art, the linear voltage stabilizing circuit has a large input-output voltage difference, the minimum requirement is generally more than 2V, the voltage stabilizing precision is related to the input-output voltage difference, and the precision is deteriorated under the condition of low input voltage.
SUMMERY OF THE UTILITY MODEL
An object of the utility model is to provide a low dropout voltage regulator circuit can make input/output pressure differential low, is applicable to the wide circuit of input power supply scope, and at low pressure during operation, reaches the effect that input/output pressure differential can be close to zero.
In order to solve the technical problem, the utility model provides a low dropout voltage regulator circuit, including Boost circuit unit, bias current circuit and power voltage regulator circuit, Boost circuit unit respectively with bias current circuit and power voltage regulator circuit are connected;
the first end of the Boost circuit unit is connected with the input end of the power supply voltage stabilizing circuit, the second end of the Boost circuit unit is connected with the grounding end of the power supply voltage stabilizing circuit, and the third end of the Boost circuit unit is connected with the input end of the bias current;
the bias current circuit comprises a second capacitor, a first resistor, a second resistor, a first unidirectional diode and a second unidirectional diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, the output end of the second unidirectional diode is connected with the output end of the first unidirectional diode and the power voltage stabilizing circuit respectively, the first end of the first resistor is connected with the first end of the Boost circuit unit and the input end of the power voltage stabilizing circuit respectively, the second end of the first resistor is connected with the input end of the first unidirectional diode, and the output end of the first unidirectional diode is connected with the output end of the second unidirectional diode and the power voltage stabilizing circuit respectively.
Further, the power supply voltage stabilizing circuit comprises a voltage stabilizing circuit, and an input power supply and a load circuit which are respectively connected with the voltage stabilizing circuit;
the voltage stabilizing circuit comprises a first capacitor, a voltage stabilizing circuit unit, a first triode, a third resistor, a fourth resistor and a third capacitor, wherein the first end of the first capacitor is respectively connected with the anode of the input power supply and the first end of the Boost circuit unit, the second end of the first capacitor is respectively connected with the cathode of the input power supply and the second end of the Boost circuit unit, the first end of the voltage stabilizing circuit unit is respectively connected with the first end of the second capacitor and the first end of the fourth resistor, the second end of the voltage stabilizing circuit unit is respectively connected with the output end of the first unidirectional diode, the output end of the second unidirectional diode and the base electrode of the first triode, the collector of the first triode is connected with the anode of the input power supply, the emitter of the first triode is connected with the first end of the third resistor, and the first end of the third resistor is also connected with the first end of the third capacitor, and the second end of the third resistor is respectively connected with the first end of the fourth resistor and the third end of the voltage stabilizing circuit unit, and the other end of the fourth resistor is respectively connected with the negative electrode of the input power supply and the second end of the third capacitor.
Furthermore, the bias current circuit also comprises another connection mode which comprises a second capacitor, a second resistor and a second one-way diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, and the output end of the second unidirectional diode is connected with the base electrode of the first triode and the second end of the voltage stabilizing circuit unit respectively.
Furthermore, the input end of the Boost circuit unit is connected to the input end of the bias current circuit and the input end of the power voltage stabilizing circuit, and the output end of the Boost circuit unit is connected to the output end of the bias current circuit and the ground end of the power voltage stabilizing circuit.
Further, the voltage stabilizing circuit is connected with the anode of the input power supply, the input end of the Boost circuit unit and the input end of the bias current circuit through the first end of the first capacitor, and the second end of the first capacitor is connected with the cathode of the input power supply, the output end of the Boost circuit unit and the output end of the bias current circuit.
Further, the voltage stabilizing circuit is connected with the first end of the load circuit through the first end of the third capacitor, and the second end of the third capacitor is connected with the second end of the load circuit.
Further, the Boost circuit unit is specifically a DC-DC Boost topology circuit.
Further, the first triode is an NPN type triode.
Implement the utility model discloses, following beneficial effect has:
the utility model discloses can provide a low dropout voltage stabilizing circuit, including Boost circuit, bias current circuit and power voltage stabilizing circuit, the Boost circuit respectively with the bias current circuit and power voltage stabilizing circuit connects. The utility model discloses can reduce and reduce input/output pressure differential under the prerequisite of guaranteeing output steady voltage precision, be applicable to the wide circuit of input power supply scope, and require at the low pressure during operation, can reach the effect that input/output pressure differential is close to zero.
Drawings
Fig. 1 is a schematic structural diagram of a low dropout voltage regulator circuit according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of a standard power supply voltage stabilizing circuit according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of another low dropout voltage regulator circuit according to an embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
Referring to fig. 1, an embodiment of the present invention provides a low dropout voltage regulator circuit, including a Boost circuit unit, a bias current circuit and a power voltage regulator circuit, where the Boost circuit unit is connected to the bias current circuit and the power voltage regulator circuit respectively;
the first end of the Boost circuit unit is connected with the input end of the power supply voltage stabilizing circuit, the second end of the Boost circuit unit is connected with the grounding end of the power supply voltage stabilizing circuit, and the third end of the Boost circuit unit is connected with the input end of the bias current;
the bias current circuit comprises a second capacitor, a first resistor, a second resistor, a first unidirectional diode and a second unidirectional diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, the output end of the second unidirectional diode is connected with the output end of the first unidirectional diode and the power voltage stabilizing circuit respectively, the first end of the first resistor is connected with the first end of the Boost circuit unit and the input end of the power voltage stabilizing circuit respectively, the second end of the first resistor is connected with the input end of the first unidirectional diode, and the output end of the first unidirectional diode is connected with the output end of the second unidirectional diode and the power voltage stabilizing circuit respectively.
In a preferred embodiment, the power supply voltage stabilizing circuit comprises a voltage stabilizing circuit, and an input power supply and a load circuit which are respectively connected with the voltage stabilizing circuit;
the voltage stabilizing circuit comprises a first capacitor, a voltage stabilizing circuit unit, a first triode, a third resistor, a fourth resistor and a third capacitor, wherein the first end of the first capacitor is respectively connected with the anode of the input power supply and the first end of the Boost circuit unit, the second end of the first capacitor is respectively connected with the cathode of the input power supply and the second end of the Boost circuit unit, the first end of the voltage stabilizing circuit unit is respectively connected with the first end of the second capacitor and the first end of the fourth resistor, the second end of the voltage stabilizing circuit unit is respectively connected with the output end of the first unidirectional diode, the output end of the second unidirectional diode and the base electrode of the first triode, the collector of the first triode is connected with the anode of the input power supply, the emitter of the first triode is connected with the first end of the third resistor, and the first end of the third resistor is also connected with the first end of the third capacitor, and the second end of the third resistor is respectively connected with the first end of the fourth resistor and the third end of the voltage stabilizing circuit unit, and the other end of the fourth resistor is respectively connected with the negative electrode of the input power supply and the second end of the third capacitor.
Specifically, as shown in fig. 2, when the voltage difference between the input power and the output power is lower than Δ U in equation (1), the output voltage may become unstable.
Wherein, UiFor input voltage, UoThe output voltage is Iout, the output current is R1, the bias resistor is β, the amplification factor of the adjusting tube T1 is β, and the voltage drop of the PN junction between the adjusting tubes be is Vbe.
In order to solve the problem, the embodiment of the present invention boosts the input power through a Boost circuit, the bias current of the regulating tube T1 is jointly provided through R1 and D1 by the input power and through R2 and D2 after boosting, and when the input power and the output voltage are low, the bias current is mainly provided through R2 and D2 by the power after boosting. Theoretically, the circuit has the advantage that the working range of the input and output voltage can be close to 0V, so that the effect of low-dropout voltage stabilization is realized.
In a preferred embodiment, the bias current circuit further comprises another connection mode, which comprises a second capacitor, a second resistor and a second unidirectional diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, and the output end of the second unidirectional diode is connected with the base electrode of the first triode and the second end of the voltage stabilizing circuit unit respectively.
Specifically, as shown in fig. 3, D1 is added to the standard driving circuit to provide bias current for the tuning tube compared with the original R1, but R1 and D1 are not necessary and the circuit can be simplified to the circuit shown in fig. 3.
In a preferred embodiment, the input end of the Boost circuit unit is connected to the input end of the bias current circuit and the input end of the power voltage stabilizing circuit, and the output end of the Boost circuit unit is connected to the output end of the bias current circuit and the ground end of the power voltage stabilizing circuit.
In a preferred embodiment, the voltage stabilizing circuit is connected to the positive electrode of the input power supply, the input end of the Boost circuit unit and the input end of the bias current circuit through the first end of the first capacitor, and the second end of the first capacitor is connected to the negative electrode of the input power supply, the output end of the Boost circuit unit and the output end of the bias current circuit.
In a preferred embodiment, the voltage stabilizing circuit is connected to the first end of the load circuit through the first end of the third capacitor, and the second end of the third capacitor is connected to the second end of the load circuit.
In a preferred embodiment, the Boost circuit unit is specifically a DC-DC Boost topology circuit.
Specifically, the Boost circuit principle can be any DC-DC Boost topology circuit, consequently the utility model discloses extensive applicability as long as under the input power supply minimum condition, can for the adjusting tube provide enough bias current can, minimum output voltage of Boost circuit and voltage stabilizing circuit output voltage differential pressure delta U must be greater than the requirement of following formula (2) promptly, wherein:
where Vf is the diode forward voltage drop, Uo-boostThe lowest output low voltage of the Boost circuit is obtained.
In a preferred embodiment, the first transistor is an NPN transistor.
The low dropout voltage stabilizing circuit provided by the embodiment comprises a Boost circuit, a bias current circuit and a power supply voltage stabilizing circuit, wherein the Boost circuit is respectively connected with the bias current circuit and the power supply voltage stabilizing circuit. The utility model discloses can reduce and reduce input/output pressure differential under the prerequisite of guaranteeing output steady voltage precision, be applicable to the wide circuit of input power supply scope, and require at the low pressure during operation, can reach the effect that input/output pressure differential is close to zero.
The above is to the detailed introduction of a low dropout voltage regulator circuit provided by the embodiment of the present invention, and the detailed individual example is adopted herein to explain the principle and the implementation mode of the present invention, and the explanation of the above embodiment is only used to help understand the method and the core idea of the present invention, and simultaneously, to the general technical personnel in the field, there is a change part on the detailed implementation mode and the application range according to the idea of the present invention, and to sum up, the content of the present specification should not be understood as the limitation of the present invention.
Claims (8)
1. A low dropout voltage regulator circuit is characterized by comprising a Boost circuit unit, a bias current circuit and a power supply voltage regulator circuit, wherein the Boost circuit unit is respectively connected with the bias current circuit and the power supply voltage regulator circuit;
the first end of the Boost circuit unit is connected with the input end of the power supply voltage stabilizing circuit, the second end of the Boost circuit unit is connected with the grounding end of the power supply voltage stabilizing circuit, and the third end of the Boost circuit unit is connected with the input end of the bias current;
the bias current circuit comprises a second capacitor, a first resistor, a second resistor, a first unidirectional diode and a second unidirectional diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, the output end of the second unidirectional diode is connected with the output end of the first unidirectional diode and the power voltage stabilizing circuit respectively, the first end of the first resistor is connected with the first end of the Boost circuit unit and the input end of the power voltage stabilizing circuit respectively, the second end of the first resistor is connected with the input end of the first unidirectional diode, and the output end of the first unidirectional diode is connected with the output end of the second unidirectional diode and the power voltage stabilizing circuit respectively.
2. The low dropout voltage regulator circuit of claim 1, wherein the power supply regulator circuit comprises a regulator circuit and an input power supply and a load circuit respectively connected to the regulator circuit;
the voltage stabilizing circuit comprises a first capacitor, a voltage stabilizing circuit unit, a first triode, a third resistor, a fourth resistor and a third capacitor, wherein the first end of the first capacitor is respectively connected with the anode of the input power supply and the first end of the Boost circuit unit, the second end of the first capacitor is respectively connected with the cathode of the input power supply and the second end of the Boost circuit unit, the first end of the voltage stabilizing circuit unit is respectively connected with the first end of the second capacitor and the first end of the fourth resistor, the second end of the voltage stabilizing circuit unit is respectively connected with the output end of the first unidirectional diode, the output end of the second unidirectional diode and the base electrode of the first triode, the collector of the first triode is connected with the anode of the input power supply, the emitter of the first triode is connected with the first end of the third resistor, and the first end of the third resistor is also connected with the first end of the third capacitor, and the second end of the third resistor is respectively connected with the first end of the fourth resistor and the third end of the voltage stabilizing circuit unit, and the other end of the fourth resistor is respectively connected with the negative electrode of the input power supply and the second end of the third capacitor.
3. The low dropout voltage regulator circuit of claim 1 wherein the bias current circuit further comprises another connection comprising a second capacitor, a second resistor, and a second unidirectional diode; the first end of the second capacitor is connected with the second end of the Boost circuit unit and the grounding end of the power voltage stabilizing circuit respectively, the second end of the second capacitor is connected with the third end of the Boost circuit unit and the first end of the second resistor respectively, the second end of the second resistor is connected with the input end of the second unidirectional diode, and the output end of the second unidirectional diode is connected with the base electrode of the first triode and the second end of the voltage stabilizing circuit unit respectively.
4. The low dropout voltage regulator circuit according to claim 1 or 2, wherein an input terminal of the Boost circuit unit is connected to an input terminal of the bias current circuit and an input terminal of the power supply voltage regulator circuit, respectively, and an output terminal of the Boost circuit unit is connected to an output terminal of the bias current circuit and a ground terminal of the power supply voltage regulator circuit, respectively.
5. The low dropout voltage regulator circuit of claim 2, wherein the voltage regulator circuit is connected to a positive terminal of an input power supply, an input terminal of the Boost circuit unit and an input terminal of the bias current circuit through a first terminal of the first capacitor, and a second terminal of the first capacitor is connected to a negative terminal of the input power supply, an output terminal of the Boost circuit unit and an output terminal of the bias current circuit.
6. The low dropout voltage regulator circuit of claim 2, wherein the regulator circuit is coupled to a first terminal of the load circuit through a first terminal of the third capacitor, and a second terminal of the third capacitor is coupled to a second terminal of the load circuit.
7. The low dropout voltage regulator circuit according to claim 1, wherein the Boost circuit unit is specifically a DC-DC Boost topology circuit.
8. The low dropout voltage regulator circuit of claim 2, wherein the first transistor is an NPN transistor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920738134.1U CN210351014U (en) | 2019-05-21 | 2019-05-21 | Low dropout voltage stabilizing circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920738134.1U CN210351014U (en) | 2019-05-21 | 2019-05-21 | Low dropout voltage stabilizing circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN210351014U true CN210351014U (en) | 2020-04-17 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920738134.1U Active CN210351014U (en) | 2019-05-21 | 2019-05-21 | Low dropout voltage stabilizing circuit |
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|---|---|
| CN (1) | CN210351014U (en) |
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- 2019-05-21 CN CN201920738134.1U patent/CN210351014U/en active Active
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