Linear power supply and electronic device

Abstract

This invention discloses a linear power supply and electronic device. The linear power supply includes a low-voltage operational amplifier circuit, a voltage output stage circuit, a regulating power transistor, and a sampling circuit. The first input terminal of the low-voltage operational amplifier circuit is connected to a reference voltage. The second input terminal of the low-voltage operational amplifier circuit is connected to the output terminal of the sampling circuit. The output terminal of the low-voltage operational amplifier circuit is connected to the input terminal of the voltage output stage circuit. The voltage output stage circuit is connected to at least two reference voltage sources. The output terminal of the voltage output stage circuit is connected to the control terminal of the regulating power transistor. The first terminal of the regulating power transistor is connected to a DC voltage source, and the second terminal of the regulating power transistor is connected to both the input terminal of the sampling circuit and the load. In this invention, when one of the reference voltage sources is insufficient to provide a stable voltage to the control terminal of the regulating power transistor, the other reference voltage sources can provide a stable voltage to the control terminal of the regulating power transistor, thereby ensuring a stable output from the regulating power transistor and improving the stability of the linear power supply.

Description

Technical Field

[0001] This invention relates to power supply technology, and more particularly to a linear power supply and electronic device. Background Technology

[0002] A linear power supply first reduces the voltage amplitude of alternating current (AC) through a transformer, then rectifies it through a rectifier circuit to obtain pulsed direct current (DC). This DC voltage is then filtered to obtain a DC voltage with slight ripple, and finally, a linear adjustment element finely adjusts the filtered DC voltage to achieve the required output voltage value and accuracy. The desired output voltage and accuracy are achieved by adjusting the voltage at the control terminal of the linear adjustment element.

[0003] In existing linear power supplies, the voltage at the control terminal of the linear adjustment element typically only covers a single voltage domain. When this voltage is unstable, it will lead to an unstable final output voltage of the linear power supply. Summary of the Invention

[0004] This invention provides a linear power supply and electronic device that can improve the stability of the linear power supply.

[0005] In a first aspect, the present invention provides a linear power supply, including a low-voltage operational amplifier circuit, a voltage output stage circuit, an adjustment power transistor, and a sampling circuit;

[0006] The first input terminal of the low-voltage operational amplifier circuit is connected to the reference voltage, the second input terminal of the low-voltage operational amplifier circuit is connected to the output terminal of the sampling circuit, and the output terminal of the low-voltage operational amplifier circuit is connected to the input terminal of the voltage output stage circuit.

[0007] The voltage output stage circuit is connected to at least two reference voltage sources, and the output terminal of the voltage output stage circuit is connected to the control terminal of the adjusting power transistor.

[0008] The first terminal of the adjustable power transistor is connected to a DC voltage source, and the second terminal of the adjustable power transistor is connected to the input terminal of the sampling circuit and the load, respectively.

[0009] Optionally, the low-voltage operational amplifier circuit includes a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor;

[0010] The first terminal of the first switching transistor and the first terminal of the second switching transistor are both connected to a low-voltage power supply. The second terminal of the first switching transistor is connected to the first terminal of the third switching transistor. The second terminal of the second switching transistor is connected to the first terminal of the fourth switching transistor. The control terminal of the first switching transistor is connected to the output terminal of the sampling circuit. The control terminal of the second switching transistor is connected to a reference voltage.

[0011] The second terminals of the third and fourth switching transistors are both grounded. The control terminals of the third and fourth switching transistors are both connected to the first terminal of the third switching transistor. The first terminal of the fourth switching transistor is connected to the input terminal of the voltage output stage circuit.

[0012] Optionally, the low-voltage operational amplifier circuit further includes a fifth switching transistor. The first terminal of the fifth switching transistor is connected to the low-voltage power supply, and the second terminal of the fifth switching transistor is connected to the first terminal of the fourth switching transistor. The control terminal of the fifth switching transistor is connected to a soft-start control signal, which controls the output voltage of the second terminal of the adjusting power transistor to rise slowly during the linear power supply startup process.

[0013] Optionally, the voltage output stage circuit includes a sixth switching transistor, a first voltage supply unit, and a second voltage supply unit;

[0014] The first terminal of the first voltage providing unit is connected to the first reference voltage source, the second terminal of the first voltage providing unit is connected to the first terminal of the sixth switching transistor, the third terminal of the first voltage providing unit is connected to the control terminal of the adjusting power transistor, and the second terminal of the sixth switching transistor is grounded.

[0015] The first terminal of the second voltage providing unit is connected to the second reference voltage source, and the second terminal of the second voltage providing unit is connected to the control terminal of the adjusting power transistor.

[0016] The control terminal of the sixth switching transistor is connected to the output terminal of the low-voltage operational amplifier circuit.

[0017] Optionally, the first voltage providing unit includes a current mirror unit, a push-pull unit, and a seventh switching transistor;

[0018] The input terminal of the current mirror unit is connected to the first reference voltage source, and the second terminal of the current mirror unit is connected to the first terminal of the push-pull unit.

[0019] The second end of the push-pull sub-unit is connected to the first end of the sixth switching transistor, and the third end of the push-pull sub-unit is connected to the first end of the seventh switching transistor.

[0020] The second terminal of the seventh switching transistor is grounded, and the control terminal of the seventh switching transistor is connected to the fourth terminal of the push-pull subunit.

[0021] Optionally, the current mirror unit includes an eighth switching transistor, a ninth switching transistor, a tenth switching transistor, an eleventh switching transistor, a twelfth switching transistor, and a thirteenth switching transistor.

[0022] The first terminals of the eighth switching transistor, the ninth switching transistor, and the tenth switching transistor are all connected to the first reference voltage source.

[0023] The second terminal of the eighth switching transistor is connected to the first terminal of the eleventh switching transistor, and the second terminal of the eleventh switching transistor is connected to the first terminal of the push-pull subunit.

[0024] The second terminal of the ninth switching transistor is connected to the first terminal of the twelfth switching transistor, and the second terminal of the twelfth switching transistor is grounded;

[0025] The second terminal of the tenth switching transistor is connected to the first terminal of the thirteenth switching transistor, and the second terminal of the thirteenth switching transistor is connected to the first terminal of the push-pull subunit.

[0026] The second terminal of the ninth switching transistor is connected to the control terminal of the eighth switching transistor, the control terminal of the ninth switching transistor, and the control terminal of the tenth switching transistor, respectively.

[0027] The second terminal of the twelfth switching transistor is connected to the control terminals of the eleventh switching transistor, the twelfth switching transistor, and the thirteenth switching transistor, respectively.

[0028] Optionally, the push-pull subunit includes a fourteenth switching transistor, a fifteenth switching transistor, a sixteenth switching transistor, and a seventeenth switching transistor;

[0029] The first terminal of the fourteenth switching transistor is connected to the second terminal of the eleventh switching transistor, the second terminal of the fourteenth switching transistor is connected to the first terminal of the sixteenth switching transistor, and the second terminal of the sixteenth switching transistor is connected to the first terminal of the sixth switching transistor.

[0030] The first terminal of the fifteenth switching transistor is connected to the second terminal of the thirteenth switching transistor, the second terminal of the fifteenth switching transistor is connected to the first terminal of the seventeenth switching transistor, and the second terminal of the seventeenth switching transistor is grounded.

[0031] The control terminal of the fourteenth switching transistor is connected to the control terminal of the fifteenth switching transistor;

[0032] The control terminal of the sixteenth switching transistor is connected to the control terminal of the seventeenth switching transistor and the second terminal of the sixteenth switching transistor, respectively.

[0033] The second terminal of the fifteenth switching transistor is connected to the first terminal of the seventh switching transistor;

[0034] The control terminal of the seventeenth switching transistor is connected to the control terminal of the seventh switching transistor.

[0035] Optionally, the second voltage providing unit includes a nineteenth switching transistor, a twentieth switching transistor, a first diode, and a protection subunit;

[0036] The first terminal of the nineteenth switching transistor and the first terminal of the twentieth switching transistor are both connected to the second reference voltage source. The second terminal of the nineteenth switching transistor is connected to the anode of the first diode. The cathode of the first diode is connected to the first terminal of the seventh switching transistor. The second terminal of the twentieth switching transistor is grounded. The second terminal of the twentieth switching transistor is connected to the control terminal of the nineteenth switching transistor and the control terminal of the twentieth switching transistor, respectively.

[0037] The first end of the protection subunit is connected to the first end of the twentieth switching transistor, and the second end of the protection subunit is connected to the second end of the twentieth switching transistor.

[0038] Optionally, the second voltage supply unit further includes a current control subunit, which includes a twenty-first switching transistor, a twenty-second switching transistor, and a twenty-third switching transistor.

[0039] The first terminal of the 21st switching transistor is connected to the second terminal of the 7th switching transistor, and the second terminal of the 21st switching transistor is grounded.

[0040] The first terminal of the 22nd switching transistor is connected to a voltage source, and the second terminal of the 22nd switching transistor is grounded.

[0041] The first terminal of the 21st switching transistor is connected to the control terminal of the 21st switching transistor and the control terminal of the 22nd switching transistor, respectively.

[0042] The first terminal of the 23rd switching transistor is connected to the second terminal of the 20th switching transistor, the second terminal of the 23rd switching transistor is grounded, and the control terminal of the 23rd switching transistor is connected to the first terminal of the 22nd switching transistor.

[0043] In a second aspect, the present invention also provides an electronic device including a linear power supply as provided in the first aspect of the present invention.

[0044] The linear power supply provided by this invention includes a low-voltage operational amplifier circuit, a voltage output stage circuit, an adjusting power transistor, and a sampling circuit. The first input terminal of the low-voltage operational amplifier circuit is connected to a reference voltage. The second input terminal of the low-voltage operational amplifier circuit is connected to the output terminal of the sampling circuit. The output terminal of the low-voltage operational amplifier circuit is connected to the input terminal of the voltage output stage circuit. The voltage output stage circuit is connected to at least two reference voltage sources. The output terminal of the voltage output stage circuit is connected to the control terminal of the adjusting power transistor. The first terminal of the adjusting power transistor is connected to a DC voltage source, and the second terminal of the adjusting power transistor is connected to both the input terminal of the sampling circuit and the load. When one of the reference voltage sources is insufficient to provide a stable voltage to the control terminal of the adjusting power transistor, the other reference voltage sources can provide a stable voltage to the control terminal of the adjusting power transistor, thereby ensuring a stable output from the adjusting power transistor and improving the stability of the linear power supply. Attached Figure Description

[0045] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0046] Figure 1 A frame structure diagram of a linear power supply provided in an embodiment of the present invention;

[0047] Figure 2 This is a partial circuit diagram of a linear power supply provided in an embodiment of the present invention. Detailed Implementation

[0048] To make the technical problems solved by the present invention, the technical solutions adopted, and the technical effects achieved clearer, the technical solutions of the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0050] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature. Moreover, the terms "first" and "second" are used merely for descriptive distinction and have no specific meaning.

[0051] Figure 1 A frame structure diagram of a linear power supply provided in an embodiment of the present invention is shown below. Figure 1 As shown, the linear power supply includes a low-voltage operational amplifier circuit 110, a voltage output stage circuit 120, an adjustment power transistor MP1, and a sampling circuit 130.

[0052] The first input terminal of the low-voltage operational amplifier circuit 110 is connected to the reference voltage VBG, the second input terminal of the low-voltage operational amplifier circuit 110 is connected to the output terminal of the sampling circuit 130, and the output terminal of the low-voltage operational amplifier circuit 110 is connected to the input terminal of the voltage output stage circuit 120. The low-voltage operational amplifier circuit 110 is used to compare the reference voltage VBG and the sampled voltage VFB fed back by the sampling circuit 130, amplify the difference between the two, and then send the amplified signal to the voltage output stage circuit 120.

[0053] The voltage output stage circuit 120 is connected to at least two reference voltage sources (exemplary). Figure 1 (Taking two reference voltage sources V2 and V3 as an example), the output terminal of the voltage output stage circuit 120 is connected to the control terminal of the regulating power transistor MP1. The voltage output stage circuit 120 is used to apply the voltage output from one of the reference voltage sources to the control terminal of the regulating power transistor MP1.

[0054] The first terminal of the power transistor MP1 is connected to the DC voltage source V4, and the second terminal Vout of the power transistor MP1 is connected to the input terminal of the sampling circuit 130 and the load, respectively.

[0055] Under normal conditions, the voltage output stage circuit 120 selects a reference voltage source as the output, and the adjusting power transistor MP1 operates in the linear region. The DC voltage source V4, after being regulated by the adjusting power transistor MP1, outputs a voltage that drives the load. For example, when the voltage of the DC voltage source V4 increases, the output voltage Vout tends to increase, causing the sampling voltage VFB acquired by the sampling circuit 130 to increase. Since the reference voltage VBG remains stable, the output signal of the low-voltage operational amplifier circuit 110 decreases, and consequently, the voltage supplied from the reference voltage source to the control terminal of the adjusting power transistor MP1 via the voltage output stage circuit 120 decreases. The adjusting power transistor MP1 operates as an emitter follower. When the voltage at the control terminal of the adjusting power transistor MP1 decreases, the output voltage Vout at the second terminal of the adjusting power transistor MP1 also decreases, thereby suppressing the upward trend of the output voltage Vout and achieving voltage regulation. When the voltage of the DC voltage source V4 decreases, the output voltage Vout tends to decrease, causing the sampling voltage VFB acquired by the sampling circuit 130 to decrease. Since the reference voltage VBG remains stable, the output signal of the low-voltage operational amplifier circuit 110 increases. Consequently, the voltage supplied by the reference voltage source to the control terminal of the regulating power transistor MP1 via the voltage output stage circuit 120 increases. The regulating power transistor MP1 operates as an emitter follower. When the voltage at the control terminal of the regulating power transistor MP1 increases, the output voltage Vout at the second terminal of the regulating power transistor MP1 also increases, thereby suppressing the decreasing trend of the output voltage Vout and achieving voltage regulation.

[0056] When one of the reference voltage sources is insufficient to provide a stable voltage to the control terminal of the regulating power transistor MP1, the other reference voltage source can provide a stable voltage to the control terminal of the regulating power transistor MP1, thereby ensuring the stable output of the regulating power transistor MP1. For example, during the process of providing voltage from reference voltage source V3 to the control terminal of the regulating power transistor MP1, if the voltage of reference voltage source V3 is too low, the voltage output by reference voltage source V2 will cause the circuit containing reference voltage source V3 to disconnect, thus allowing reference voltage source V2 to provide voltage to the control terminal of the regulating power transistor MP1; conversely, during the process of providing voltage from reference voltage source V2 to the control terminal of the regulating power transistor MP1, if the voltage of reference voltage source V2 is too low, the voltage output by reference voltage source V3 will cause the circuit containing reference voltage source V2 to disconnect, thus allowing reference voltage source V3 to provide voltage to the control terminal of the regulating power transistor MP1.

[0057] The linear power supply provided in this embodiment of the invention includes a low-voltage operational amplifier circuit, a voltage output stage circuit, an adjusting power transistor, and a sampling circuit. The first input terminal of the low-voltage operational amplifier circuit is connected to a reference voltage. The second input terminal of the low-voltage operational amplifier circuit is connected to the output terminal of the sampling circuit. The output terminal of the low-voltage operational amplifier circuit is connected to the input terminal of the voltage output stage circuit. The voltage output stage circuit is connected to at least two reference voltage sources. The output terminal of the voltage output stage circuit is connected to the control terminal of the adjusting power transistor. The first terminal of the adjusting power transistor is connected to a DC voltage source, and the second terminal of the adjusting power transistor is connected to both the input terminal of the sampling circuit and the load. When one of the reference voltage sources is insufficient to provide a stable voltage to the control terminal of the adjusting power transistor, the other reference voltage sources can provide a stable voltage to the control terminal of the adjusting power transistor, thereby ensuring a stable output from the adjusting power transistor and improving the stability of the linear power supply.

[0058] For example, such as Figure 1 As shown, the sampling circuit 130 includes resistors R5 and R6. The first end of resistor R5 is connected to the second end of the power transistor MP1, the second end of resistor R5 is connected to the first end of resistor R6, the second end of resistor R6 is grounded, and the second input terminal of the low-voltage operational amplifier circuit 110 is connected to the first end of resistor R6.

[0059] Figure 2 A partial circuit diagram of a linear power supply provided for an embodiment of the present invention, such as... Figure 2 As shown, exemplarily, the low-voltage operational amplifier circuit 110 includes a first switching transistor M2, a second switching transistor M3, a third switching transistor M5, and a fourth switching transistor M6.

[0060] The first terminal of the first switching transistor M2 and the first terminal of the second switching transistor M3 are both connected to the low-voltage power supply V1. The second terminal of the first switching transistor M2 is connected to the first terminal of the third switching transistor M5. The second terminal of the second switching transistor M3 is connected to the first terminal of the fourth switching transistor M6. The control terminal of the first switching transistor M2 is connected to the output terminal of the sampling circuit 120 to receive the sampled voltage VFB. The control terminal of the second switching transistor M3 is connected to the reference voltage VBG.

[0061] The second terminals of both the third switching transistor M5 and the fourth switching transistor M6 are grounded. The control terminals of both the third and fourth switching transistors are connected to the first terminal of the third switching transistor M5. The first terminal of the fourth switching transistor M6 is connected to the input terminal of the voltage output stage circuit 120. The third switching transistor M5 and the fourth switching transistor M6 form a current mirror. The controlled current of the current mirror (i.e., the current of the fourth switching transistor M6) is equal to the input reference current (i.e., the current of the third switching transistor M5), meaning the input-output current transfer ratio is equal to 1. Its characteristic is that the output current is a proportional "copy" of the input current. For example, when the output voltage Vout increases and the acquisition voltage VFB increases, the current of the third switching transistor M5 increases, and the current of the fourth switching transistor M6 also increases.

[0062] For example, in some embodiments of the present invention, the low-voltage operational amplifier circuit 110 further includes a fifth switching transistor M4. The first terminal of the fifth switching transistor M4 is connected to the low-voltage power supply V1, and the second terminal of the fifth switching transistor M4 is connected to the first terminal of the fourth switching transistor M6. The control terminal of the fifth switching transistor M4 is connected to a soft-start control signal ST. During the linear power supply startup process, the output voltage Vout of the second terminal of the control power transistor MP1 is slowly increased to prevent the impact of instantaneous large current on the control power transistor MP1. For example, during the linear power supply startup process, the voltage of the soft-start control signal ST is slowly increased, the control power transistor MP1 is slowly turned on, the output voltage Vout is slowly increased, and the acquisition voltage VFB is also slowly increased. When the voltage of the soft-start control signal ST rises to the reference voltage VBG, the voltage of the soft-start control signal ST is cut off, and the reference voltage VBG is connected simultaneously.

[0063] For example, such as Figure 2 As shown, the low-voltage operational amplifier circuit 110 also includes a switching transistor M1. The first terminal of the switching transistor M1 is connected to the low-voltage power supply V1. The second terminal of the switching transistor M1 is connected to the first terminal of the first switching transistor M2 and the first terminal of the second switching transistor M3 respectively. The control terminal of the switching transistor M1 is connected to the switching signal PB1 to control whether the low-voltage power supply V1 is connected.

[0064] For example, such as Figure 2 As shown, in some embodiments of the present invention, the voltage output stage circuit 120 includes a sixth switching transistor M7, a first voltage providing unit 121, and a second voltage providing unit 122.

[0065] The first terminal of the first voltage providing unit 121 is connected to the first reference voltage source V2, the second terminal of the first voltage providing unit 121 is connected to the first terminal of the sixth switching transistor M7, and the third terminal of the first voltage providing unit 121 is connected to the control terminal of the adjusting power transistor MP1. Figure 2 The P terminal of the sixth switching transistor M7 is connected to ground.

[0066] The first terminal of the second voltage providing unit 122 is connected to the second reference voltage source V3, and the second terminal of the second voltage providing unit 122 is connected to the control terminal of the power transistor MP1. Figure 2 (P end in the middle) connection.

[0067] The control terminal of the sixth switching transistor M7 is connected to the output terminal of the low-voltage operational amplifier circuit 110 (i.e., the first terminal of the fourth switching transistor M6).

[0068] For example, the first voltage providing unit 121 includes a current mirror unit 1211, a push-pull unit 1212, and a seventh switching transistor M21.

[0069] The input terminal of the current mirror unit 1211 is connected to the first reference voltage source V2, and the second terminal of the current mirror unit 1211 is connected to the first terminal of the push-pull unit 1212.

[0070] The second end of the push-pull sub-unit 1212 is connected to the first end of the sixth switching transistor M7, and the third end of the push-pull sub-unit 1212 is connected to the first end of the seventh switching transistor M21.

[0071] The second terminal of the seventh switching transistor M21 is grounded, and the control terminal of the seventh switching transistor M21 is connected to the fourth terminal of the push-pull subunit 1212.

[0072] For example, such as Figure 2 As shown, the current mirror unit 1211 includes an eighth switching transistor M16, a ninth switching transistor M17, a tenth switching transistor M18, an eleventh switching transistor M13, a twelfth switching transistor M14, and a thirteenth switching transistor M15.

[0073] The first terminal of the eighth switching transistor M16, the first terminal of the ninth switching transistor M17, and the first terminal of the tenth switching transistor M18 are all connected to the first reference voltage source V2.

[0074] The second terminal of the eighth switching transistor M16 is connected to the first terminal of the eleventh switching transistor M13, and the second terminal of the eleventh switching transistor M13 is connected to the first terminal of the push-pull subunit 1212.

[0075] The second terminal of the ninth switching transistor M17 is connected to the first terminal of the twelfth switching transistor M14, and the second terminal of the twelfth switching transistor M14 is grounded.

[0076] The second terminal of the tenth switching transistor M18 is connected to the first terminal of the thirteenth switching transistor M15, and the second terminal of the thirteenth switching transistor M15 is connected to the first terminal of the push-pull subunit 1212.

[0077] The second terminal of the ninth switching transistor M17 is connected to the control terminals of the eighth switching transistor M16, the ninth switching transistor M17, and the tenth switching transistor M18, respectively. The eighth switching transistor M16, together with the ninth switching transistor M17 and the tenth switching transistor M18, forms a current mirror.

[0078] The second terminal of the twelfth switching transistor M14 is connected to the control terminals of the eleventh switching transistor M13, the twelfth switching transistor M14, and the thirteenth switching transistor M15, respectively. The thirteenth switching transistor M15, together with the eleventh switching transistor M13 and the twelfth switching transistor M14, forms a current mirror.

[0079] For example, such as Figure 2 As shown, the push-pull subunit 1212 includes a fourteenth switching transistor M10, a fifteenth switching transistor M11, a sixteenth switching transistor M9, and a seventeenth switching transistor M12.

[0080] The first terminal of the fourteenth switching transistor M10 is connected to the second terminal of the eleventh switching transistor M13, the second terminal of the fourteenth switching transistor M10 is connected to the first terminal of the sixteenth switching transistor M9, and the second terminal of the sixteenth switching transistor M9 is connected to the first terminal of the sixth switching transistor M7.

[0081] The first terminal of the fifteenth switching transistor M11 is connected to the second terminal of the thirteenth switching transistor M15, the second terminal of the fifteenth switching transistor M11 is connected to the first terminal of the seventeenth switching transistor M12, and the second terminal of the seventeenth switching transistor M12 is grounded.

[0082] The control terminal of the fourteenth switching transistor M10 is connected to the control terminal of the fifteenth switching transistor M11, and the control terminal of the sixteenth switching transistor M9 is connected to the control terminal of the seventeenth switching transistor M12 and the second terminal of the sixteenth switching transistor M9, respectively.

[0083] The second terminal of the fifteenth switching transistor M11 is connected to the first terminal of the seventh switching transistor M21. The control terminal of the seventeenth switching transistor M12 is connected to the control terminal of the seventh switching transistor M21.

[0084] For example, such as Figure 2 As shown, a switching transistor M8 is connected in series between the sixth switching transistor M7 and the sixteenth switching transistor M9. The first terminal of the switching transistor M8 is connected to the second terminal of the sixteenth switching transistor M9, and the second terminal of the switching transistor M8 is connected to the first terminal of the sixth switching transistor M7. The control terminal of the switching transistor M8 is connected to the switching signal S1, which is used to control whether the voltage output stage circuit 120 is working.

[0085] For example, such as Figure 2 As shown, the second voltage supply unit 122 includes a nineteenth switching transistor M19, a twentieth switching transistor M20, a first diode D1, and a protection subunit 1221.

[0086] The first terminal of the nineteenth switching transistor M19 and the first terminal of the twentieth switching transistor M20 are both connected to the second reference voltage source V3. The second terminal of the nineteenth switching transistor M19 is connected to the anode of the first diode D1. The cathode of the first diode D1 is connected to the first terminal of the seventh switching transistor M21. The second terminal of the twentieth switching transistor M20 is grounded. The second terminal of the twentieth switching transistor M20 is connected to the control terminal of the nineteenth switching transistor M19 and the control terminal of the twentieth switching transistor M20, respectively. The nineteenth switching transistor M19 and the twentieth switching transistor M20 form a current mirror.

[0087] The first terminal of the protection subunit 1221 is connected to the first terminal of the twentieth switching transistor M20, and the second terminal of the protection subunit 1221 is connected to the second terminal of the twentieth switching transistor M20. The protection subunit 1221 is used to protect the nineteenth switching transistor M19 and the twentieth switching transistor M20.

[0088] For example, during the process of providing voltage from reference voltage source V3 to the control terminal of adjusting power transistor MP1, if the voltage of reference voltage source V3 is too low, the voltage output by reference voltage source V2 will cause the first diode D1 to turn off, and the circuit of reference voltage source V3 will be disconnected, thereby providing voltage from reference voltage source V2 to the control terminal of adjusting power transistor MP1; during the process of providing voltage from reference voltage source V2 to the control terminal of adjusting power transistor MP1, if the voltage of reference voltage source V2 is too low, the voltage output by reference voltage source V3 will cause the first diode D1 to turn on, and the circuit of reference voltage source V2 will be disconnected, thereby providing voltage from reference voltage source V3 to the control terminal of adjusting power transistor MP1.

[0089] For example, such as Figure 2 As shown, in some embodiments of the present invention, the protection subunit 1221 includes a resistor R1 and a diode D2. The first end of the resistor R1 is connected to the first end of the twentieth switching transistor M20, the second end of the resistor R1 is connected to the second end of the twentieth switching transistor M20, the anode of the diode D2 is connected to the second end of the twentieth switching transistor M20, and the cathode of the diode D2 is connected to the first end of the twentieth switching transistor M20.

[0090] For example, such as Figure 2As shown, in some embodiments of the present invention, a clamping diode D3 is also provided at the output terminal of the voltage output stage circuit 120. The anode of the clamping diode D3 is grounded, and the cathode of the clamping diode D3 is connected to the output terminal of the voltage output stage circuit 120. The clamping diode D3 is used for clamping. When the voltage at the output terminal of the voltage output stage circuit 120 is higher than the reverse breakdown voltage of the clamping diode D3, the clamping diode D3 is turned on to prevent the voltage output by the voltage output stage circuit 120 from being too large and causing damage to the regulating power transistor MP1.

[0091] For example, such as Figure 2 As shown, in some embodiments of the present invention, the output terminal of the voltage output stage circuit 120 is further provided with a pull-down resistor R3 to provide resistive output state and capability.

[0092] For example, such as Figure 2 As shown, in some embodiments of the present invention, the second voltage providing unit 122 further includes a current control subunit 1222, which includes a twenty-first switching transistor M23, a twenty-second switching transistor M24, and a twenty-third switching transistor M27.

[0093] The first terminal of the twenty-first switching transistor M23 is connected to the second terminal of the seventh switching transistor M21, and the second terminal of the twenty-first switching transistor M23 is grounded.

[0094] The first terminal of the twenty-second switching transistor M24 is connected to the voltage source Vt, and the second terminal of the twenty-second switching transistor M24 is grounded.

[0095] The first terminal of the twenty-first switching transistor M23 is connected to the control terminal of the twenty-first switching transistor M23 and the control terminal of the twenty-second switching transistor M24.

[0096] The first terminal of the 23rd switching transistor M27 is connected to the second terminal of the 20th switching transistor M20. The second terminal of the 23rd switching transistor M27 is grounded. The control terminal of the 23rd switching transistor M27 is connected to the first terminal of the 22nd switching transistor M24.

[0097] For example, when the current flowing through the seventh switching transistor M21 increases, the current flowing through the twenty-first switching transistor M23 increases; due to the proportional mirroring, the current flowing through the twenty-second switching transistor M24 increases, the control terminal voltage of the twenty-third switching transistor M27 decreases, the current flowing through the twenty-third switching transistor M27 decreases, the current flowing through the twentieth switching transistor M20 decreases, and due to the proportional mirroring, the current flowing through the nineteenth switching transistor M19 decreases. Finally, it is deduced that the current flowing through the seventh switching transistor M21 decreases, thus achieving the purpose of stabilizing the current.

[0098] For example, such as Figure 2 As shown, a switching transistor M22 is also provided between the seventh switching transistor M21 and the twenty-first switching transistor M23. The first terminal of switching transistor M22 is connected to the second terminal of the seventh switching transistor M21, and the second terminal of switching transistor M22 is connected to the first terminal of the twenty-first switching transistor M23. The control terminal of switching transistor M22 is connected to the switching signal S1. A switching transistor M25 is also provided between the voltage source Vt and the twenty-second switching transistor M24. The first terminal of switching transistor M25 is connected to the voltage source Vt, and the second terminal of switching transistor M25 is connected to the first terminal of the twenty-second switching transistor M24. The control terminal of switching transistor M25 is connected to the switching signal PB2. A switching transistor M28 is also provided between the twenty-third switching transistor M27 and the twentieth switching transistor M20. The first terminal of switching transistor M28 is connected to the second terminal of the twentieth switching transistor M20, and the second terminal of switching transistor M28 is connected to the first terminal of the twenty-third switching transistor M27. The control terminal of switching transistor M28 is connected to the switching signal S2. A switching transistor M26 is also provided between the twenty-third switching transistor M27 and ground. The first terminal of the switching transistor M26 is connected to the second terminal of the twenty-third switching transistor M27. The second terminal of the switching transistor M26 is grounded. The control terminal of the switching transistor M26 is connected to the switching signal NP1.

[0099] For example, such as Figure 2 As shown, the current control subunit 1222 also includes a resistor R4 and a capacitor C1. The first end of the capacitor C1 is connected to the first end of the twenty-second switching transistor M24, and the second end of the capacitor C1 is connected to the first end of the resistor R4. The second end of the resistor R4 is connected to the control terminal of the twenty-second switching transistor M24. The resistor R4 and the capacitor C1 are used to compensate for the stability of the current control subunit 1222.

[0100] This invention also provides an electronic device, including the linear power supply provided in any of the foregoing embodiments of this invention, which has the corresponding functions and effects of the foregoing embodiments.

[0101] In the description herein, it should be understood that the terms "upper," "lower," "left," "right," etc., are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of description and simplification of operation, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0102] In the description of this specification, references to terms such as "an embodiment," "example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0103] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style of the specification is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0104] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are merely for explaining the principles of the invention and should not be construed as limiting the scope of protection of the invention in any way. Based on this explanation, those skilled in the art can readily conceive of other specific embodiments of the invention without inventive effort, and these embodiments will all fall within the scope of protection of the present invention.

Claims

1. A linear power supply, characterized in that, This includes a low-voltage operational amplifier circuit, a voltage output stage circuit, a regulating power transistor, and a sampling circuit; The first input terminal of the low-voltage operational amplifier circuit is connected to the reference voltage, the second input terminal of the low-voltage operational amplifier circuit is connected to the output terminal of the sampling circuit, and the output terminal of the low-voltage operational amplifier circuit is connected to the input terminal of the voltage output stage circuit. The voltage output stage circuit is connected to at least two reference voltage sources, and the output terminal of the voltage output stage circuit is connected to the control terminal of the adjusting power transistor. The first terminal of the adjustable power transistor is connected to a DC voltage source, and the second terminal of the adjustable power transistor is connected to the input terminal of the sampling circuit and the load, respectively. The voltage output stage circuit includes a sixth switching transistor, a first voltage supply unit, and a second voltage supply unit; The first terminal of the first voltage providing unit is connected to the first reference voltage source, the second terminal of the first voltage providing unit is connected to the first terminal of the sixth switching transistor, the third terminal of the first voltage providing unit is connected to the control terminal of the adjusting power transistor, and the second terminal of the sixth switching transistor is grounded. The first terminal of the second voltage providing unit is connected to the second reference voltage source, and the second terminal of the second voltage providing unit is connected to the control terminal of the adjusting power transistor. The control terminal of the sixth switching transistor is connected to the output terminal of the low-voltage operational amplifier circuit. The first voltage providing unit includes a current mirror unit, a push-pull unit, and a seventh switching transistor; The input terminal of the current mirror unit is connected to the first reference voltage source, and the second terminal of the current mirror unit is connected to the first terminal of the push-pull unit. The second end of the push-pull sub-unit is connected to the first end of the sixth switching transistor, and the third end of the push-pull sub-unit is connected to the first end of the seventh switching transistor. The second terminal of the seventh switching transistor is grounded, and the control terminal of the seventh switching transistor is connected to the fourth terminal of the push-pull subunit. The second voltage supply unit includes a nineteenth switching transistor, a twentieth switching transistor, a first diode, and a protection subunit; The first terminal of the nineteenth switching transistor and the first terminal of the twentieth switching transistor are both connected to the second reference voltage source. The second terminal of the nineteenth switching transistor is connected to the anode of the first diode. The cathode of the first diode is connected to the first terminal of the seventh switching transistor. The second terminal of the twentieth switching transistor is grounded. The second terminal of the twentieth switching transistor is connected to the control terminal of the nineteenth switching transistor and the control terminal of the twentieth switching transistor, respectively. The cathode of the first diode serves as the second terminal of the second voltage supply unit. The first end of the protection subunit is connected to the first end of the twentieth switching transistor, and the second end of the protection subunit is connected to the second end of the twentieth switching transistor.

2. The linear power supply according to claim 1, characterized in that, The low-voltage operational amplifier circuit includes a first switching transistor, a second switching transistor, a third switching transistor, and a fourth switching transistor. The first terminal of the first switching transistor and the first terminal of the second switching transistor are both connected to a low-voltage power supply. The second terminal of the first switching transistor is connected to the first terminal of the third switching transistor. The second terminal of the second switching transistor is connected to the first terminal of the fourth switching transistor. The control terminal of the first switching transistor is connected to the output terminal of the sampling circuit. The control terminal of the second switching transistor is connected to a reference voltage. The second terminals of the third and fourth switching transistors are both grounded. The control terminals of the third and fourth switching transistors are both connected to the first terminal of the third switching transistor. The first terminal of the fourth switching transistor is connected to the input terminal of the voltage output stage circuit.

3. The linear power supply according to claim 2, characterized in that, The low-voltage operational amplifier circuit also includes a fifth switching transistor. The first terminal of the fifth switching transistor is connected to the low-voltage power supply, and the second terminal of the fifth switching transistor is connected to the first terminal of the fourth switching transistor. The control terminal of the fifth switching transistor is connected to a soft-start control signal, which controls the output voltage of the second terminal of the adjusting power transistor to rise slowly during the linear power supply startup process.

4. The linear power supply according to claim 1, characterized in that, The current mirror unit includes an eighth switching transistor, a ninth switching transistor, a tenth switching transistor, an eleventh switching transistor, a twelfth switching transistor, and a thirteenth switching transistor; The first terminals of the eighth switching transistor, the ninth switching transistor, and the tenth switching transistor are all connected to the first reference voltage source. The second terminal of the eighth switching transistor is connected to the first terminal of the eleventh switching transistor, and the second terminal of the eleventh switching transistor is connected to the first terminal of the push-pull subunit. The second terminal of the ninth switching transistor is connected to the first terminal of the twelfth switching transistor, and the second terminal of the twelfth switching transistor is grounded; The second terminal of the tenth switching transistor is connected to the first terminal of the thirteenth switching transistor, and the second terminal of the thirteenth switching transistor is connected to the first terminal of the push-pull subunit. The second terminal of the ninth switching transistor is connected to the control terminal of the eighth switching transistor, the control terminal of the ninth switching transistor, and the control terminal of the tenth switching transistor, respectively. The second terminal of the twelfth switching transistor is connected to the control terminals of the eleventh switching transistor, the twelfth switching transistor, and the thirteenth switching transistor, respectively.

5. The linear power supply according to claim 4, characterized in that, The push-pull subunit includes a fourteenth switching transistor, a fifteenth switching transistor, a sixteenth switching transistor, and a seventeenth switching transistor; The first terminal of the fourteenth switching transistor is connected to the second terminal of the eleventh switching transistor, the second terminal of the fourteenth switching transistor is connected to the first terminal of the sixteenth switching transistor, and the second terminal of the sixteenth switching transistor is connected to the first terminal of the sixth switching transistor. The first terminal of the fifteenth switching transistor is connected to the second terminal of the thirteenth switching transistor, the second terminal of the fifteenth switching transistor is connected to the first terminal of the seventeenth switching transistor, and the second terminal of the seventeenth switching transistor is grounded. The control terminal of the fourteenth switching transistor is connected to the control terminal of the fifteenth switching transistor; The control terminal of the sixteenth switching transistor is connected to the control terminal of the seventeenth switching transistor and the second terminal of the sixteenth switching transistor, respectively. The second terminal of the fifteenth switching transistor is connected to the first terminal of the seventh switching transistor; The control terminal of the seventeenth switching transistor is connected to the control terminal of the seventh switching transistor.

6. The linear power supply according to claim 1, characterized in that, The second voltage supply unit also includes a current control subunit, which includes a twenty-first switching transistor, a twenty-second switching transistor, and a twenty-third switching transistor. The first terminal of the 21st switching transistor is connected to the second terminal of the 7th switching transistor, and the second terminal of the 21st switching transistor is grounded. The first terminal of the 22nd switching transistor is connected to a voltage source, and the second terminal of the 22nd switching transistor is grounded. The first terminal of the 21st switching transistor is connected to the control terminal of the 21st switching transistor and the control terminal of the 22nd switching transistor, respectively. The first terminal of the 23rd switching transistor is connected to the second terminal of the 20th switching transistor, the second terminal of the 23rd switching transistor is grounded, and the control terminal of the 23rd switching transistor is connected to the first terminal of the 22nd switching transistor.

7. An electronic device, characterized in that, Includes the linear power supply as described in any one of claims 1-6.

Images