CN214670300U - Linear voltage stabilizing circuit for realizing zero-voltage difference - Google Patents
Linear voltage stabilizing circuit for realizing zero-voltage difference Download PDFInfo
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- CN214670300U CN214670300U CN202121407190.0U CN202121407190U CN214670300U CN 214670300 U CN214670300 U CN 214670300U CN 202121407190 U CN202121407190 U CN 202121407190U CN 214670300 U CN214670300 U CN 214670300U
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Abstract
The utility model provides a realize linear voltage stabilizing circuit of zero-voltage difference, including adjustment unit, comparing element, the reference voltage unit that is used for receiving the voltage of input and generates reference voltage and the feedback unit that is used for receiving the voltage after the regulation and generates feedback voltage; the comparison unit is respectively connected with the reference voltage unit, the feedback unit and the adjustment unit; the comparison unit receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage; the adjusting unit receives the voltage of the input end and the control voltage, adjusts the voltage of the input end and outputs the adjusted voltage. The reference voltage unit generates fixed reference voltage, the feedback unit samples the regulated voltage output by the regulation unit, the reference voltage and the sampled voltage are input to the comparison unit for comparison, and the on-resistance of the regulation unit is controlled according to the comparison result so as to regulate the regulated voltage output by the regulation unit, thereby achieving the purpose of stably outputting the voltage.
Description
Technical Field
The utility model relates to a realize zero-pressure differential's linear voltage stabilizing circuit technical field, especially relate to a realize zero-pressure differential's linear voltage stabilizing circuit.
Background
A low dropout linear regulator (LDO) is often applied in a scenario of supplying power to a chip, and a main performance index of the LDO is an input/output voltage difference.
The input-output voltage difference of the low dropout linear voltage regulator circuit widely used at present is about 0.7V, if the input voltage is less than the output voltage plus the voltage difference of LDO itself, the low dropout linear voltage regulator circuit can not maintain the normal output voltage, even if the output exists, the output voltage is lower than the input voltage, and the load carrying capacity is poor.
The low dropout linear voltage regulator circuit has no problem in most application scenarios because the input and output voltages of most circuits have relatively large voltage differences. However, for some circuits with wide input voltage variation range, especially for the application scenario requiring "the input voltage is higher than the set voltage to start voltage stabilization, and is lower than the set voltage to keep direct connection", it is not sufficient. Due to the existence of the input-output voltage difference, when the input voltage is lower than the output voltage, the low-dropout linear voltage-stabilizing circuit cannot realize complete through connection.
For the above problems, the following two solutions are generally adopted at present:
1. the voltage is increased and then reduced, namely, the input voltage is increased to enough voltage difference, and then the voltage is reduced by a voltage reduction circuit, so that stable output can be realized;
2. a DCDC (direct current to direct current) chip with a 100% duty cycle is used, which can achieve a shoot-through function when the input voltage is lower than the output voltage.
Both of the above solutions meet the requirements, but have the following disadvantages:
1. the cost is high, the total cost of the DCDC chip is several times of that of the low dropout linear voltage stabilizing circuit, and the cost is higher if the voltage is increased and then reduced;
2. the circuit area is large, the DCDC chip needs a series of peripheral elements such as inductors and the like to be matched, and the circuit layout area is large, so that the miniaturization of the product cannot be realized; if the voltage is increased and then reduced, the area is larger;
3. performance is wasted, and DCDC chips are generally used for circuits with current requirements of several hundred milliamperes and more, which can cause serious performance waste when applied to small devices with small power.
SUMMERY OF THE UTILITY MODEL
In view of the above, the present invention has been made to provide a linear voltage regulator circuit that achieves a zero-dropout voltage that overcomes or at least partially solves the above-mentioned problems.
In order to solve the problem, the utility model discloses a realize linear voltage stabilizing circuit of zero-voltage difference is applied to the voltage of regulation input to voltage to target unit after the output is adjusted, include: the voltage regulator comprises an adjusting unit, a comparing unit, a reference voltage unit and a feedback unit, wherein the reference voltage unit is used for receiving the voltage of the input end and generating a reference voltage, and the feedback unit is used for receiving the regulated voltage and generating a feedback voltage;
the comparison unit is respectively connected with the reference voltage unit, the feedback unit and the adjustment unit; the comparison unit receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage;
the adjusting unit receives the voltage of the input end and the control voltage, adjusts the voltage of the input end and outputs the adjusted voltage;
when the feedback voltage is greater than the reference voltage, the comparison unit increases the control voltage, so that the adjustment unit decreases the adjusted voltage;
when the feedback voltage is less than the reference voltage, the comparison unit decreases the control voltage so that the adjustment unit increases the adjusted voltage;
when the feedback voltage is smaller than the reference voltage and the voltage of the input end is smaller than a set voltage, the adjusting unit outputs the adjusted voltage with the voltage value equal to the voltage of the input end.
Optionally, the adjusting unit comprises a field effect transistor Q1 and a resistor R3; the drain of the field effect transistor Q1 is connected to the input terminal, the source of the field effect transistor Q1 is connected to the target unit, the gate of the field effect transistor Q1 is connected to the comparison unit, the first end of the resistor R3 is connected between the reference voltage unit and the drain of the field effect transistor Q1, and the second end of the resistor R3 is connected between the gate of the field effect transistor Q1 and the comparison unit.
Optionally, the reference voltage unit comprises a resistor R1 and a diode U1; the first end of the resistor R1 is connected between the input end and the drain of the field effect transistor Q1, the first end of the resistor R1 is connected with the first end of the resistor R3, the second end of the resistor R1 is connected with the first end of the diode U1, the third end of the diode U1 is connected with the comparison unit, the third end of the diode U1 is connected between the second end of the resistor R1 and the first end of the diode U1, and the second end of the diode U1 is grounded.
Optionally, the feedback unit comprises a resistor R4 and a resistor R5; the first terminal of the resistor R4 is connected between the adjusting unit and the target unit, the second terminal of the resistor R4 is connected with the first terminal of the resistor R5, and the second terminal of the resistor R5 is grounded.
Optionally, the comparing unit includes a resistor R2, a transistor Q2, and a transistor Q3; the first end of the resistor R2 is connected to the emitter of the transistor Q2 and the emitter of the transistor Q3, the second end of the resistor R2 is grounded, the base of the transistor Q2 is connected to the second end of the diode U1, the base of the transistor Q2 is connected between the second end of the resistor R1 and the first end of the diode U1, the collector of the transistor Q2 is connected to the gate of the fet Q1 and the second end of the resistor R3, the collector of the transistor Q3 is connected between the first end of the resistor R1 and the first end of the resistor R3, and the base of the transistor Q3 is connected between the second end of the resistor R4 and the first end of the resistor R5.
Optionally, the adjusting unit further includes a resistor R6 and a transistor Q4; the first end of the resistor R6 is connected with the input end, the second end of the resistor R6 is connected with the drain of the field effect transistor Q1, the base of the triode Q4 is connected between the second end of the resistor R6 and the drain of the field effect transistor Q1, the emitter of the triode Q4 is connected between the first end of the resistor R3 and the first end of the resistor R6, and the collector of the triode Q4 is connected between the second end of the resistor R3 and the gate of the field effect transistor Q1.
Optionally, the reference voltage unit further includes a resistor R7 and a resistor R8; the first end of the resistor R7 is connected with the second end of the diode U1, the first end of the resistor R7 is connected between the second end of the resistor R1 and the first end of the diode U1, the second end of the resistor R7 is connected with the first end of the resistor R8, the base of the triode Q2 is connected between the second end of the resistor R7 and the first end of the resistor R8, and the second end of the resistor R8 is grounded.
Optionally, the fet Q1 is a P-channel enhancement fet.
Optionally, the transistor Q2 and the transistor Q3 are NPN transistors.
Optionally, the transistor Q4 is a PNP transistor.
The utility model discloses a following advantage: the voltage regulation circuit comprises a regulation unit, a comparison unit, a reference voltage unit and a feedback unit, wherein the reference voltage unit is used for receiving the voltage of the input end and generating a reference voltage, and the feedback unit is used for receiving the regulated voltage and generating a feedback voltage; the comparison unit is respectively connected with the reference voltage unit, the feedback unit and the adjustment unit; the comparison unit receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage; the adjusting unit receives the voltage of the input end and the control voltage, adjusts the voltage of the input end and outputs the adjusted voltage; when the feedback voltage is greater than the reference voltage, the comparison unit increases the control voltage, so that the adjustment unit decreases the adjusted voltage; when the feedback voltage is less than the reference voltage, the comparison unit decreases the control voltage so that the adjustment unit increases the adjusted voltage; when the feedback voltage is smaller than the reference voltage and the voltage of the input end is smaller than a set voltage, the adjusting unit outputs the adjusted voltage with the voltage value equal to the voltage of the input end. The reference voltage unit generates fixed reference voltage, the feedback unit samples the regulated voltage output by the regulation unit, the reference voltage and the sampled voltage are input to the comparison unit for comparison, and the on-resistance of the regulation unit is controlled according to the comparison result so as to regulate the regulated voltage output by the regulation unit, thereby achieving the purpose of stabilizing the output voltage; when the on-resistance of the adjusting unit 1 drops to zero, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5.
Drawings
Fig. 1 is a schematic diagram of a first structure of a linear voltage stabilizing circuit for realizing zero-dropout according to the present invention;
fig. 2 is a second schematic diagram of the linear voltage stabilizing circuit according to the present invention;
FIG. 3 is a third schematic diagram of a linear voltage regulator circuit for achieving zero-dropout according to the present invention;
fig. 4 is a fourth schematic diagram of the linear voltage stabilizing circuit according to the present invention.
Description of the drawings: 1. the device comprises an adjusting unit, 2, a reference voltage unit, 3, a comparing unit, 4, a feedback unit, 5, an input end, 6 and an output end.
Detailed Description
In order to make the above objects, features and advantages of the present invention more comprehensible, the present invention is described in detail with reference to the accompanying drawings and the detailed description.
One of the core concepts of the present invention is that the voltage is adjusted by an adjusting unit 1, a comparing unit 3, a reference voltage unit 2 for receiving the voltage of the input terminal 5 and generating a reference voltage, and a feedback unit 4 for receiving the adjusted voltage and generating a feedback voltage; the comparison unit 3 is respectively connected with the reference voltage unit 2, the feedback unit 4 and the adjustment unit 1; the comparison unit 3 receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage; the adjusting unit 1 receives the voltage of the input end 5 and the control voltage, adjusts the voltage of the input end 5, and outputs the adjusted voltage; when the feedback voltage is greater than the reference voltage, the comparison unit 3 increases the control voltage, so that the adjustment unit 1 decreases the adjusted voltage; when the feedback voltage is smaller than the reference voltage, the comparison unit 3 decreases the control voltage so that the adjustment unit 1 raises the adjusted voltage; when the feedback voltage is smaller than the reference voltage and the voltage of the input terminal is smaller than the set voltage, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5. A fixed reference voltage is generated through the reference voltage unit 2, the feedback unit 4 samples the regulated voltage output by the regulating unit 1, the reference voltage and the sampled voltage are input into the comparing unit 3 for comparison, and the on-resistance of the regulating unit 1 is controlled according to the comparison result so as to regulate the regulated voltage output by the regulating unit 1, thereby achieving the purpose of stabilizing the output voltage; when the on-resistance of the adjusting unit 1 drops to zero, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5.
It should be noted that the linear voltage stabilizing circuit is applied to regulate the voltage at the input terminal 5, and output the regulated voltage to the target unit through the output terminal 6.
Referring to fig. 1 to fig. 4, there are shown schematic structural diagrams of a linear voltage stabilizing circuit for realizing zero-voltage difference according to the present invention, which may specifically include:
the voltage regulator comprises an adjusting unit 1, a comparing unit 3, a reference voltage unit 2 for receiving the voltage of the input end 5 and generating a reference voltage, and a feedback unit 4 for receiving the regulated voltage and generating a feedback voltage;
the comparison unit 3 is respectively connected with the reference voltage unit 2, the feedback unit 4 and the adjustment unit 1; the comparison unit 3 receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage;
the adjusting unit 1 receives the voltage of the input end 5 and the control voltage, adjusts the voltage of the input end 5, and outputs the adjusted voltage;
when the feedback voltage is greater than the reference voltage, the comparison unit 3 increases the control voltage, so that the adjustment unit 1 decreases the adjusted voltage;
when the feedback voltage is smaller than the reference voltage, the comparison unit 3 decreases the control voltage so that the adjustment unit 1 raises the adjusted voltage;
when the feedback voltage is smaller than the reference voltage and the voltage of the input terminal is smaller than the set voltage, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5.
In the embodiment of the present application, the voltage is adjusted by an adjusting unit 1, a comparing unit 3, a reference voltage unit 2 for receiving the voltage of the input terminal 5 and generating a reference voltage, and a feedback unit 4 for receiving the adjusted voltage and generating a feedback voltage; the comparison unit 3 is respectively connected with the reference voltage unit 2, the feedback unit 4 and the adjustment unit 1; the comparison unit 3 receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage; the adjusting unit 1 receives the voltage of the input end 5 and the control voltage, adjusts the voltage of the input end 5, and outputs the adjusted voltage; when the feedback voltage is greater than the reference voltage, the comparison unit 3 increases the control voltage, so that the adjustment unit 1 decreases the adjusted voltage; when the feedback voltage is smaller than the reference voltage, the comparison unit 3 decreases the control voltage so that the adjustment unit 1 raises the adjusted voltage; when the feedback voltage is smaller than the reference voltage and the voltage of the input terminal is smaller than the set voltage, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5. A fixed reference voltage is generated through the reference voltage unit 2, the feedback unit 4 samples the regulated voltage output by the regulating unit 1, the reference voltage and the sampled voltage are input into the comparing unit 3 for comparison, and the on-resistance of the regulating unit 1 is controlled according to the comparison result so as to regulate the regulated voltage output by the regulating unit 1, thereby achieving the purpose of stabilizing the output voltage; when the on-resistance of the adjusting unit 1 drops to zero, the adjusting unit 1 outputs the adjusted voltage having the voltage value equal to the voltage of the input terminal 5.
Hereinafter, a linear voltage regulating circuit that realizes a zero-dropout voltage in the present exemplary embodiment will be further described.
In an embodiment of the present application, the adjusting unit 1 includes a field effect transistor Q1 and a resistor R3; the drain of the fet Q1 is connected to the input terminal 5, the source of the fet Q1 is connected to the input terminal 5, the gate of the fet Q1 is connected to the fourth terminal of the comparison unit 3, the first terminal of the resistor R3 is connected between the first terminal of the reference voltage unit 2 and the drain of the fet Q1, and the second terminal of the resistor R3 is connected between the gate of the fet Q1 and the fourth terminal of the comparison unit 3.
As an example, the gate of the fet Q1 receives the control voltage transmitted by the fourth terminal of the comparison unit 3, and the source of the fet Q1 outputs different regulated voltages according to the voltage value of the control voltage; the regulated voltage output by the source of the fet Q1 is determined by the on-resistance of the fet Q1, and the on-resistance of the fet Q1 changes depending on the voltage value of the control voltage. That is, the larger the voltage value of the control voltage received by the gate of the fet Q1, the larger the on-resistance of the fet Q1, the smaller the regulated voltage output by the source of the fet Q1; conversely, the smaller the voltage value of the control voltage is, the larger the regulated voltage output by the source of the field effect transistor Q1 is, so that the voltage value of the regulated voltage can be controlled to a preset value.
In a specific implementation, the fet Q1 of the adjustment unit 1 may be replaced by a triode.
In an embodiment of the present application, the reference voltage unit 2 includes a resistor R1 and a diode U1; the first end of the resistor R1 is connected between the input terminal 5 and the drain of the field effect transistor Q1, the first end of the resistor R1 is connected with the first end of the resistor R3, the second end of the resistor R1 is connected with the first end of the diode U1, the third end of the diode U1 is connected with the first end of the comparison unit 3, the third end of the diode U1 is connected between the second end of the resistor R1 and the first end of the diode U1, and the second end of the diode U1 is grounded.
As an example, the diode U1 receives the voltage of the input terminal 5 to generate a reference voltage, and transmits the reference voltage to the comparing unit 3, so that the comparison voltage obtains a reference voltage.
In an embodiment of the present application, the feedback unit 4 includes a resistor R4 and a resistor R5; the first terminal of the resistor R4 is connected between the adjustment unit 1 and the target unit, the second terminal of the resistor R4 is connected to the first terminal of the resistor R5, and the second terminal of the resistor R5 is grounded.
As an example, the feedback unit 4 divides the voltage to form a feedback voltage to the comparison unit 3 after acquiring the adjusted voltage of the adjustment unit 1, so that the comparison unit 3 changes the voltage value of the control voltage according to the feedback voltage.
In an embodiment of the present application, the comparing unit 3 includes a resistor R2, a transistor Q2, and a transistor Q3; the first end of the resistor R2 is connected to the emitter of the transistor Q2 and the emitter of the transistor Q3, the second end of the resistor R2 is grounded, the base of the transistor Q2 is connected to the second end of the diode U1, the second end of the resistor R1 and the first end of the diode U1, the collector of the transistor Q2 is connected to the gate of the fet Q1 and the second end of the resistor R3, the collector of the transistor Q3 is connected between the first end of the resistor R1 and the first end of the resistor R3, and the base of the transistor Q3 is connected between the second end of the resistor R4 and the first end of the resistor R5.
As an example, the comparing unit 3 compares the reference voltage with the sampling voltage, and controls the on-resistance of the adjusting unit 1 according to the comparison result to adjust the adjusted voltage output by the adjusting unit 1, thereby achieving the purpose of stabilizing the output voltage.
In a specific implementation, when the output regulated voltage decreases, the feedback voltage decreases, the on-resistance of the transistor Q3 increases, the on-resistance of the transistor Q2 decreases, the control voltage output by the transistor Q2 decreases, the gate voltage of the fet Q1 decreases, the on-resistance of the fet Q1 decreases, and the regulated voltage output by the source of the fet Q1 increases, so that the output regulated voltage stabilizes at a preset voltage value; when the output regulated voltage rises, the feedback voltage rises, the on-resistance of the triode Q3 falls, the on-resistance of the triode Q2 rises, the control voltage output by the triode Q2 falls, the gate voltage of the field-effect transistor Q1 rises, the on-resistance of the field-effect transistor Q1 increases, the regulated voltage output by the source of the field-effect transistor Q1 falls, and the output regulated voltage is stabilized at a preset voltage value; when the voltage of the input end is lower than the regulated voltage, the feedback voltage is lower than the reference voltage, the triode Q3 is cut off, the triode Q2 is turned on, the grid voltage of the field effect transistor Q1 is pulled to be the lowest, and the field effect transistor Q1 enters a through state, namely, the regulated voltage with the voltage value equal to the voltage of the input end is directly output.
In one specific implementation, when the feedback voltage is greater than the reference voltage, the on-resistance of the fet Q1 increases, and the regulated voltage decreases, thereby decreasing the feedback voltage to a level equal to the reference voltage; when the feedback voltage is smaller than the reference voltage, the on-resistance of the field effect transistor Q1 is reduced, and the regulated voltage is increased, so that the feedback voltage is restored to a level equal to the reference voltage; when the on-resistance of the fet Q1 is reduced to zero and the feedback voltage cannot be restored to be equal to the reference voltage, the fet Q1 maintains the state of zero on-resistance, i.e., the through state, and the voltage value of the input terminal is equal to the voltage value of the regulated voltage.
In one specific implementation, when the on-resistance of the fet Q1 is zero, the voltage value of the voltage at the input terminal is equal to the voltage value of the regulated voltage, and if the voltage value of the voltage at the input terminal is smaller than the voltage value of the set voltage, the voltage value of the regulated voltage is also smaller than the set voltage, where the set voltage is the reference voltage (1+ R4/R5).
In one implementation, the transistor Q3 and the transistor Q2 may both be replaced by field effect transistors.
In an embodiment of the present application, the adjusting unit 1 further includes a resistor R6 and a transistor Q4; the first end of the resistor R6 is connected to the input terminal 5, the second end of the resistor R6 is connected to the drain of the fet Q1, the base of the transistor Q4 is connected between the second end of the resistor R6 and the drain of the fet Q1, the emitter of the transistor Q4 is connected between the first end of the resistor R3 and the first end of the resistor R6, and the collector of the transistor Q4 is connected between the second end of the resistor R3 and the gate of the fet Q1.
In an embodiment of the present application, the reference voltage unit 2 further includes a resistor R7 and a resistor R8; the first end of the resistor R7 is connected with the second end of the diode U1, the first end of the resistor R7 is connected between the second end of the resistor R1 and the first end of the diode U1, the second end of the resistor R7 is connected with the first end of the resistor R8, the base of the triode Q2 is connected between the second end of the resistor R7 and the first end of the resistor R8, and the second end of the resistor R8 is grounded.
In an embodiment of the present application, the fet Q1 is a P-channel enhancement fet.
In an embodiment of the present application, the transistor Q2 and the transistor Q3 are NPN transistors.
In an embodiment of the present application, the transistor Q4 is a PNP transistor.
In an embodiment of the present application, a fixed reference voltage is generated by the reference voltage unit 2, the feedback unit 4 samples the regulated voltage output by the adjustment unit 1, the reference voltage and the sampled voltage are both input to the comparison unit 3 for comparison, and the on-resistance of the adjustment unit 1 is controlled according to the comparison result to adjust the regulated voltage output by the adjustment unit 1, thereby achieving the purpose of stabilizing the output voltage of the circuit. The zero-voltage-difference voltage stabilizing function can be realized by the linear voltage stabilizing circuit only by a small number of components, so that the cost is saved; the area for arranging the circuit is small, so that the miniaturization of the product can be better realized; the static power consumption of the whole circuit is extremely low, and the circuit can be used for low-power-consumption products, so that resource waste is avoided.
Finally, it should also be noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or terminal that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or terminal. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or terminal that comprises the element.
The above has introduced the linear voltage stabilizing circuit for realizing zero-pressure difference provided by the present invention in detail, and the specific examples are applied herein to explain the principle and the implementation of the present invention, and the description of the above embodiments is only used to help understand the method and the core idea of the present invention; meanwhile, for the general technical personnel in the field, according to the idea of the present invention, there are changes in the specific implementation and application scope, to sum up, the content of the present specification should not be understood as the limitation of the present invention.
Claims (10)
1. A linear voltage regulator circuit for achieving zero-dropout regulation, for regulating a voltage at an input terminal and outputting the regulated voltage to a target unit, comprising: the voltage regulator comprises an adjusting unit, a comparing unit, a reference voltage unit and a feedback unit, wherein the reference voltage unit is used for receiving the voltage of the input end and generating a reference voltage, and the feedback unit is used for receiving the regulated voltage and generating a feedback voltage;
the comparison unit is respectively connected with the reference voltage unit, the feedback unit and the adjustment unit; the comparison unit receives the reference voltage and the feedback voltage, generates a control voltage and outputs the control voltage;
the adjusting unit receives the voltage of the input end and the control voltage, adjusts the voltage of the input end and outputs the adjusted voltage;
when the feedback voltage is greater than the reference voltage, the comparison unit increases the control voltage, so that the adjustment unit decreases the adjusted voltage;
when the feedback voltage is less than the reference voltage, the comparison unit decreases the control voltage so that the adjustment unit increases the adjusted voltage;
when the feedback voltage is smaller than the reference voltage and the voltage of the input end is smaller than a set voltage, the adjusting unit outputs the adjusted voltage with the voltage value equal to the voltage of the input end.
2. The linear voltage regulating circuit for realizing zero dropout according to claim 1, wherein the regulating unit comprises a field effect transistor Q1 and a resistor R3; the drain of the field effect transistor Q1 is connected to the input terminal, the source of the field effect transistor Q1 is connected to the target unit, the gate of the field effect transistor Q1 is connected to the comparison unit, the first end of the resistor R3 is connected between the reference voltage unit and the drain of the field effect transistor Q1, and the second end of the resistor R3 is connected between the gate of the field effect transistor Q1 and the comparison unit.
3. The linear voltage regulating circuit for realizing zero dropout according to claim 2, wherein the reference voltage unit comprises a resistor R1 and a diode U1; the first end of the resistor R1 is connected between the input end and the drain of the field effect transistor Q1, the first end of the resistor R1 is connected with the first end of the resistor R3, the second end of the resistor R1 is connected with the first end of the diode U1, the third end of the diode U1 is connected with the comparison unit, the third end of the diode U1 is connected between the second end of the resistor R1 and the first end of the diode U1, and the second end of the diode U1 is grounded.
4. The linear voltage regulating circuit achieving zero dropout according to claim 3, wherein the feedback unit comprises a resistor R4 and a resistor R5; the first terminal of the resistor R4 is connected between the adjusting unit and the target unit, the second terminal of the resistor R4 is connected with the first terminal of the resistor R5, and the second terminal of the resistor R5 is grounded.
5. The linear voltage regulating circuit for realizing zero dropout according to claim 4, wherein the comparing unit comprises a resistor R2, a transistor Q2 and a transistor Q3; the first end of the resistor R2 is connected to the emitter of the transistor Q2 and the emitter of the transistor Q3, the second end of the resistor R2 is grounded, the base of the transistor Q2 is connected to the second end of the diode U1, the base of the transistor Q2 is connected between the second end of the resistor R1 and the first end of the diode U1, the collector of the transistor Q2 is connected to the gate of the fet Q1 and the second end of the resistor R3, the collector of the transistor Q3 is connected between the first end of the resistor R1 and the first end of the resistor R3, and the base of the transistor Q3 is connected between the second end of the resistor R4 and the first end of the resistor R5.
6. The linear voltage regulating circuit for realizing zero dropout according to claim 2, wherein the regulating unit further comprises a resistor R6 and a transistor Q4; the first end of the resistor R6 is connected with the input end, the second end of the resistor R6 is connected with the drain of the field effect transistor Q1, the base of the triode Q4 is connected between the second end of the resistor R6 and the drain of the field effect transistor Q1, the emitter of the triode Q4 is connected between the first end of the resistor R3 and the first end of the resistor R6, and the collector of the triode Q4 is connected between the second end of the resistor R3 and the gate of the field effect transistor Q1.
7. The linear voltage regulating circuit for realizing zero dropout according to claim 5, wherein the reference voltage unit further comprises a resistor R7 and a resistor R8; the first end of the resistor R7 is connected with the second end of the diode U1, the first end of the resistor R7 is connected between the second end of the resistor R1 and the first end of the diode U1, the second end of the resistor R7 is connected with the first end of the resistor R8, the base of the triode Q2 is connected between the second end of the resistor R7 and the first end of the resistor R8, and the second end of the resistor R8 is grounded.
8. The linear voltage regulating circuit for realizing zero dropout according to claim 2, wherein the fet Q1 is a P-channel enhancement fet.
9. The linear voltage regulator circuit of claim 5, wherein the transistor Q2 and the transistor Q3 are NPN transistors.
10. The linear voltage regulator circuit of claim 6, wherein the transistor Q4 is a PNP transistor.
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121407190.0U CN214670300U (en) | 2021-06-23 | 2021-06-23 | Linear voltage stabilizing circuit for realizing zero-voltage difference |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202121407190.0U CN214670300U (en) | 2021-06-23 | 2021-06-23 | Linear voltage stabilizing circuit for realizing zero-voltage difference |
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| CN214670300U true CN214670300U (en) | 2021-11-09 |
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- 2021-06-23 CN CN202121407190.0U patent/CN214670300U/en active Active
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