Low-ripple adjustable constant-voltage power supply module

Abstract

A low-ripple adjustable constant-voltage power supply module belongs to the technical field of electronic device power supply and comprises an input filtering unit, a voltage adjusting unit, a feedback unit and an output filtering unit. According to the utility model, after the voltage is converted through the voltage adjusting unit, the change of the output voltage can be directly predicted in advance without passing through the output filtering unit and is fed back to the voltage adjusting unit for adjustment, and the voltage change caused by the change of an external load can be directly adjusted through the voltage adjusting unit; the dynamic performance of the output voltage is improved, the use of complex feedback and adjustment circuits is avoided, the ripple of the output voltage is reduced, and the power supply quality is improved; in addition, the output filtering unit adopts a diode inductor capacitor, so that output voltage ripples are reduced, and the dynamic performance is improved. And finally, components with lower cost are adopted for construction, so that the design cost is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply for electronic devices, and particularly relates to a low-ripple adjustable constant-voltage power supply module. Background Art

[0002] In circuit design, most power supply circuits use expensive high-frequency switching power supplies or integrated linear voltage regulators for power supply. When using a high-frequency switching power supply for power supply, due to the high-speed conduction and turn-off of the switching transistor, the output voltage ripple is relatively large, and the entire product cannot operate stably, unable to meet some design requirements. When using an integrated linear voltage regulator, since the internal circuit of the integrated linear voltage regulator has been packaged, it is impossible to debug the power supply indicators, which brings limitations to designers. Products with special requirements for the transient response of the output voltage cannot be used. If the design requirements need to be met, additional costs are required for circuit redesign and change or replacement of the design scheme. Therefore, there is an urgent need for a power supply module that can output low noise, low temperature ripple, and low interference. Summary of the Utility Model

[0003] In order to solve the above problems, the utility model provides a low-ripple adjustable constant-voltage power supply module, which is characterized in that the low-ripple adjustable constant-voltage power supply module includes: an input filtering unit, a voltage adjustment unit, a feedback unit, and an output filtering unit; the input filtering unit is electrically connected to the voltage adjustment unit, filters the external input voltage, and inputs it to the voltage adjustment unit; the voltage adjustment unit is electrically connected to the feedback unit, clamps the input voltage to a set value, and outputs it to the feedback unit; the feedback unit is electrically connected to the output end of the voltage adjustment unit, and the output end of the voltage adjustment unit is electrically connected to the output filtering unit.

[0004] Preferably, the voltage adjustment unit includes: a first resistor, a first triode, a second resistor, and a second triode; the first triode is a PNP-type triode; the second triode is an NPN-type triode; the input filtering unit is connected to the base of the second triode through the first resistor; the collector of the second triode is connected to the base of the first triode; the emitter of the second triode is grounded; the second resistor provides a bias voltage for the first triode to control the on-off of the first triode; the input filtering unit is connected to the collector of the first triode and is connected to the base of the first triode through the second resistor; the emitter of the first triode is electrically connected to the feedback unit; the first resistor provides a bias voltage for the second triode to control the on-off of the second triode, and further controls the on-off of the first triode; by setting the resistance values of the second resistor and the first resistor, the voltage output by the voltage adjustment unit is clamped at the set value.

[0005] Preferably, the feedback unit includes a third resistor, a third capacitor, and a fourth capacitor;

[0006] The third resistor and the fourth capacitor form an RC series circuit, which is connected in parallel with the third capacitor to form a feedback circuit; the feedback terminal of the feedback circuit is connected to the base of the second triode, and the on / off of the second triode is controlled according to the voltage value.

[0007] Preferably, the output filtering unit includes a second inductor, a second capacitor, and a diode;

[0008] The second inductor is connected in series in the power supply circuit; one end of the second capacitor is connected to the power supply circuit, and the other end is grounded to form a freewheeling circuit. When the external load fluctuates, the freewheeling circuit conducts freewheeling; the input end of the diode is grounded, and the output end is connected to the output line.

[0009] Preferably, the voltage adjustment unit further includes a fourth resistor, a seventh resistor, a fifth capacitor, a voltage stabilizing diode, and a third triode;

[0010] The third triode is an NPN type triode; the fourth resistor and the fifth capacitor form a parallel circuit, which is electrically connected to the output end of the output filtering unit and grounded through the seventh resistor; the parallel circuit is also connected to the base of the third triode through the voltage stabilizing diode; the emitter of the third triode is grounded, and the collector is connected to the base of the second triode. When the voltage output by the power supply circuit is higher than the set output value, the third triode conducts, pulling down the base voltage of the second triode, causing the second triode to turn off, and further causing the base voltage of the first triode to increase and turn off, thereby adjusting the voltage level of the power supply circuit.

[0011] Preferably, the voltage adjustment unit further includes a fifth resistor and a sixth resistor;

[0012] Both ends of the fifth resistor are grounded and the base of the second triode respectively; both ends of the sixth resistor are grounded and the base of the third triode respectively.

[0013] Preferably, the input filtering unit includes a first inductor and a first capacitor;

[0014] The first inductor is connected in series in the power supply circuit; both ends of the first capacitor are grounded and the power supply circuit respectively.

[0015] Compared with the prior art, the beneficial effects of the present utility model are:

[0016] The technical solution provided by the present utility model includes: an input filtering unit, a voltage regulating unit, a feedback unit, and an output filtering unit; in the present utility model, after the voltage is converted by the voltage regulating unit, it does not need to pass through the output filtering unit, and the change of the output voltage can be directly predicted in advance and fed back to the voltage regulating unit for adjustment. The voltage change caused by the change of the external load can also be directly adjusted by the voltage regulating unit for the output voltage, improving the dynamic performance of the output voltage, avoiding the use of complex feedback and adjustment circuits, reducing the output voltage ripple, and improving the power supply quality; in addition, the output filtering unit uses a diode inductor capacitor, reducing the output voltage ripple and improving the dynamic performance. Finally, the present utility model is built with components with lower costs, reducing the design cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the device composition of the low-ripple adjustable constant-voltage power supply module in the present utility model;

[0018] Among them, Q1 - the first triode; Q2 - the second triode; Q3 - the third triode; R1 - the first resistor; R2 - the second resistor; R3 - the third resistor; R4 - the fourth resistor; R5 - the fifth resistor; R6 - the sixth resistor; R7 - the seventh resistor; C1 - the first capacitor; C2 - the second capacitor; C3 - the third capacitor; C4 - the fourth capacitor; C5 - the fifth capacitor; L1 - the first inductor; L2 - the second inductor; Z1 - the voltage regulator diode; D1 - the diode. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] In order to better understand the present utility model, the content of the present utility model will be further described below in conjunction with the accompanying drawings of the specification and examples.

[0020] Embodiment 1:

[0021] This embodiment provides a low-ripple adjustable constant-voltage power supply module, and the device composition of the low-ripple adjustable constant-voltage power supply module is as Figure 1 shown, including: an input filtering unit, a voltage regulating unit, a feedback unit, and an output filtering unit;

[0022] The input filtering unit is electrically connected to the voltage regulating unit, filters the external input voltage and inputs it to the voltage regulating circuit; the voltage regulating circuit is electrically connected to the voltage feedback circuit, clamps the input voltage to a set value and outputs it to the voltage feedback unit; the feedback terminal of the voltage feedback unit is electrically connected to the voltage regulating unit, and the output terminal is electrically connected to the output filtering unit.

[0023] The voltage adjustment unit includes: a first resistor R1, a first triode Q1, a second resistor R2, and a second triode Q2; the first triode Q1 is a PNP type triode; the second triode Q2 is an NPN type triode; the input filtering unit is connected to the base of the second triode Q2 through the first resistor R1; the collector of the second triode Q2 is connected to the base of the first triode Q1; the emitter of the second triode Q2 is grounded; the second resistor R2 provides a bias voltage for the first triode Q1 to control the on / off of the first triode Q1; the input filtering unit is connected to the collector of the first triode Q1 and is connected to the base of the first triode Q1 through the second resistor R2; the emitter of the first triode Q1 is electrically connected to the feedback unit; the first resistor R1 provides a bias voltage for the second triode Q2 to control the on / off of the second triode Q2, and further controls the on / off of the first triode Q1; by setting the resistance values of the second resistor R2 and the first resistor R1, the voltage output by the voltage adjustment unit is clamped at a set value.

[0024] The feedback unit includes: a third resistor R3, a third capacitor C3, and a fourth capacitor C4; the third resistor R3 and the fourth capacitor C4 form an RC series circuit and are connected in parallel with the third capacitor C3 to form a feedback circuit; the feedback terminal of the feedback circuit is connected to the base of the second triode Q2 to control the on / off of the second triode Q2 according to the voltage value.

[0025] The output filtering unit includes: a second inductor L2, a second capacitor C2, and a diode D1; the second inductor L2 is connected in series in the power supply circuit; one end of the second capacitor C2 is connected to the power supply circuit and the other end is grounded to form a freewheeling circuit, and when the external load fluctuates, the freewheeling circuit conducts freewheeling; the input end of the diode D1 is grounded and the output end is connected to the output line.

[0026] The voltage adjustment unit further includes: a fourth resistor R4, a seventh resistor R7, a fifth capacitor C5, a voltage regulator diode Z1, and a third triode Q3; the third triode Q3 is an NPN type triode; the fourth resistor R4 and the fifth capacitor C5 form a parallel circuit, the parallel circuit is electrically connected to the voltage output terminal of the power supply circuit and is grounded through the seventh resistor R7; the parallel circuit is also connected to the base of the third triode Q3 through the voltage regulator diode Z1; the emitter of the third triode Q3 is grounded and the collector is connected to the base of the second triode Q2. When the voltage output by the power supply circuit is higher than the set output value, the third triode Q3 conducts, pulling down the base voltage of the second triode Q2, causing the second triode Q2 to turn off, and further causing the base voltage of the first triode Q1 to increase and turn off, thereby adjusting the voltage level of the power supply circuit.

[0027] The voltage adjustment unit further includes: a fifth resistor R5 and a sixth resistor R6; two ends of the fifth resistor R5 are respectively grounded and connected to the base of the second triode Q2; the sixth resistor R6 is respectively grounded and connected to the base of the third triode Q3.

[0028] The input filtering unit includes: a first inductor L1 and a first capacitor C1; the first inductor L1 is connected in series in the power supply loop; two ends of the first capacitor C1 are respectively grounded and connected to the power supply loop.

[0029] Embodiment 2:

[0030] This embodiment provides a low-ripple adjustable constant-voltage power supply module. The working principle of the low-ripple adjustable constant-voltage power supply module is as follows:

[0031] The input voltage passes through the inductor L1 and the filtering capacitor C1 to obtain a stable and smooth voltage.

[0032] The voltage after input filtering enters the voltage adjustment unit and is connected to the emitter of the triode Q1 in the voltage adjustment circuit. The collector of the triode Q1 is connected to the voltage feedback unit and the output filtering unit. The filtered voltage after entering the voltage adjustment unit also provides a bias voltage for the base of the triode Q1 through the bias resistor R2 to meet the on-off conditions of the emitter and collector of Q1. The voltage after input filtering provides a bias voltage for the base of the triode Q2 through the resistor R1 to turn on the collector and emitter of Q2, pulling down the voltage between the emitter and base of the triode Q1, and then controlling the on-off of the emitter and collector of the triode Q1 to control the voltage. By setting the resistance values of R1 and R2, the control of the voltage level can be realized. The voltage after input filtering also provides a voltage for the collector of the triode Q3 through the resistor R1 to adjust the magnitude of the output voltage. The resistor R5 is connected to the base of the triode Q2 and then grounded to prevent the triode Q2 from being mis-conducted between the collector and emitter due to interference problems, resulting in out-of-control output voltage. The base of the triode Q3 is grounded through the resistor R8 to prevent the base of the triode Q3 from being mis-conducted between the collector and emitter of the triode Q3, the triode Q2, and the triode Q1 due to interference problems, resulting in out-of-control output voltage. At the same time, a stable working circuit is provided for the voltage regulator Z1.

[0033] The voltage after voltage adjustment passes through the output voltage filtering circuit including the inductor L2 and the capacitor C2 to obtain a stable output voltage. When the voltage of the power supply load changes sharply, the output filtering unit can perform freewheeling through the diode D1, the inductor L2, and the capacitor C2 to maintain voltage stability until the voltage feedback loop intervenes to adjust the output voltage.

[0034] After the output voltage is divided by resistors R4 and R7 in the voltage adjustment unit, it is connected to the base of transistor Q3 through voltage regulator Z1. When the output voltage is higher than the set voltage, the voltage between the base and emitter of transistor Q3 increases, causing the collector and emitter of transistor Q3 to conduct, further pulling down the voltage between the base and emitter of transistor Q2, and causing the collector and emitter of transistor Q2 to turn off. The collector and emitter of transistor Q2 turn off, increasing the voltage between the emitter and base of transistor Q1, causing the emitter and collector of transistor Q1 to turn off, reducing the output voltage, and achieving a stable output of the output voltage.

[0035] The voltage after voltage adjustment is connected to the base of transistor Q1 through resistors R3, capacitors C4 and C3 in the voltage feedback unit. When the output voltage passes through the voltage adjustment unit, it does not need to pass through the output filtering unit, and the change of the output voltage can be predicted in advance, so as to further adjust the voltage between the base and emitter of transistor Q2 to control the voltage between the emitter and base of transistor Q1 and control the output voltage, thereby further reducing the ripple of the output voltage.

[0036] After the output voltage goes through the entire working process, the final output voltage reaches a stable ultra-low ripple output voltage.

[0037] Obviously, the described embodiments are some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

Claims

1. A low ripple adjustable constant voltage power supply module, characterized in that: The low ripple adjustable constant voltage power supply module comprises: an input filter unit, a voltage adjustment unit, a feedback unit and an output filter unit; The input filter unit is electrically connected to the voltage adjustment unit, and filters the external input voltage before inputting it into the voltage adjustment unit; the voltage adjustment unit is electrically connected to the feedback unit, and clamps the input voltage to a set value and outputs it to the feedback unit; the feedback unit is electrically connected to the output end of the voltage adjustment unit, and the output end of the voltage adjustment unit is electrically connected to the output filter unit.

2. A low ripple adjustable constant voltage power supply module as claimed in claim 1, characterized in that: The voltage adjustment unit comprises: a first resistor (R1), a first transistor (Q1), a second resistor (R2) and a second transistor (Q2); The first transistor (Q1) is a PNP transistor; the second transistor (Q2) is an NPN transistor; the input filter unit is connected to the base of the second transistor (Q2) through the first resistor (R1); the collector of the second transistor (Q2) is connected to the base of the first transistor (Q1); the emitter of the second transistor (Q2) is grounded; the second resistor (R2) provides a bias voltage for the first transistor (Q1) to control the on and off of the first transistor (Q1); the input filter unit is connected to the base of the second transistor (Q2) through the first resistor (R1); the collector of the second transistor (Q2) is connected to the base of the first transistor (Q1); the emitter of the second transistor (Q2) is grounded; the second resistor (R2) provides a bias voltage for the first transistor (Q1) to control the on and off of the first transistor (Q1); The collector of a transistor (Q1) is connected, and is connected to the base of the first transistor (Q1) through the second resistor (R2); the emitter of the first transistor (Q1) is electrically connected to the feedback unit; the first resistor (R1) provides a bias voltage for the second transistor (Q2), controls the on-off of the second transistor (Q2), and further controls the on-off of the first transistor (Q1); and by setting the resistance values ​​of the second resistor (R2) and the first resistor (R1), the voltage output by the voltage adjustment unit is clamped at a set value.

3. A low ripple adjustable constant voltage power supply module as claimed in claim 2, characterized in that: The feedback unit comprises: a third resistor (R3), a third capacitor (C3) and a fourth capacitor (C4); The third resistor (R3) and the fourth capacitor (C4) form an RC series circuit and are connected in parallel with the third capacitor (C3) to form a feedback circuit; the feedback end of the feedback circuit is connected to the base of the second transistor (Q2), and the on and off of the second transistor (Q2) is controlled according to the voltage value.

4. A low ripple adjustable constant voltage power supply module as claimed in claim 3, characterized in that: The output filter unit comprises: a second inductor (L2), a second capacitor (C2) and a diode (D1); The second inductor (L2) is connected in series in the power supply circuit; one end of the second capacitor (C2) is connected to the power supply circuit and the other end is grounded, forming a freewheeling circuit. When the external load fluctuates, the freewheeling circuit performs freewheeling; the input end of the diode (D1) is grounded and the output end is connected to the output line.

5. A low ripple adjustable constant voltage power supply module as claimed in claim 4, characterized in that: The voltage adjustment unit further includes: a fourth resistor (R4), a seventh resistor (R7), a fifth capacitor (C5), a voltage regulator tube (Z1) and a third triode (Q3); The third transistor (Q3) is an NPN transistor; the fourth resistor (R4) and the fifth capacitor (C5) form a parallel circuit, the parallel circuit is electrically connected to the output end of the output filter unit and is grounded through the seventh resistor (R7); the parallel circuit is also connected to the base of the third transistor (Q3) through the voltage regulator (Z1); the emitter of the third transistor (Q3) is grounded, and the collector is connected to the base of the second transistor (Q2); when the voltage output by the power supply circuit is higher than the set output value, the third transistor (Q3) is turned on, the base voltage of the second transistor (Q2) is lowered, causing the second transistor (Q2) to be disconnected, thereby causing the base voltage of the first transistor (Q1) to increase and be disconnected, thereby adjusting the voltage level of the power supply circuit.

6. A low ripple adjustable constant voltage power supply module as claimed in claim 5, characterized in that: The voltage adjustment unit further includes: a fifth resistor (R5) and a sixth resistor (R6); Two ends of the fifth resistor (R5) are respectively connected to the ground and the base of the second transistor (Q2); and the sixth resistor (R6) is respectively connected to the ground and the base of the third transistor (Q3).

7. A low ripple adjustable constant voltage power supply module as claimed in claim 1, characterized in that: The input filter unit comprises: a first inductor (L1) and a first capacitor (C1); The first inductor (L1) is connected in series in the power supply circuit; and two ends of the first capacitor (C1) are respectively connected to the ground and the power supply circuit.

Images