CN217693074U

CN217693074U - Wide-range low-power-consumption power supply starting circuit, power supply circuit and electronic device

Info

Publication number: CN217693074U
Application number: CN202221163440.5U
Authority: CN
Inventors: 叶书雄; 陈聪鹏; 王刚; 王志军
Original assignee: Xiamen Haisuo Technology Co ltd
Current assignee: Xiamen Haisuo Technology Co ltd
Priority date: 2022-05-16
Filing date: 2022-05-16
Publication date: 2022-10-28
Anticipated expiration: 2032-05-16

Abstract

The utility model relates to a circuit technical field. The utility model discloses a wide range low-power consumption's power starting circuit, power supply circuit and electron device, wherein, wide range low-power consumption's power starting circuit is used for starting the power chip in the power supply circuit, including getting electric resistance circuit, switch circuit and turn-off circuit, get the input of electric resistance circuit and be used for connecing power supply, get the output of electric resistance circuit and connect the power end of power chip, switch circuit is used for controlling the break-make of getting electric resistance circuit, and switch circuit is configured to be in the on-state when getting electric resistance circuit's input and having the input of power supply; the shutdown circuit is configured to control the switching circuit to be turned off when the output voltage of the power supply circuit reaches a set value. The utility model has the advantages of wide range power supply input, low power consumption.

Description

Wide-range low-power-consumption power supply starting circuit, power supply circuit and electronic device

Technical Field

The utility model belongs to the technical field of the circuit, specifically relate to a power starting circuit, power supply circuit and electron device of wide region low-power consumption.

Background

Some existing electronic devices, such as portable power supplies, need to meet both a 12V adapter and photovoltaic (high voltage) power supply, and a power chip (such as a power chip 2843/2845/3845 and the like) of a power circuit of these electronic devices needs 1-2mA for a starting current, and a starting voltage is about 8.4V-9V, considering that the 12V adapter has a certain error range, and when designing, it is necessary to ensure that 11V starts normally, so a resistor for taking power from an input cannot be too large, for example, the output of the adapter is 11V-9V, and a current flowing through a power taking resistor is 1mA, and a resistance value of the resistor is about 2k Ω (2V/1 mA). If the high-voltage input is compatible, for example, the maximum input voltage of the photovoltaic voltage may reach 120V or even higher, the power-taking resistor is very hot, and thus a plurality of resistors with high power are required to be connected in parallel, as shown in fig. 1, if the zener diode Z2 is a 15V zener diode, a voltage drop of 120-15=105v is generated across the power-taking resistor, and the power: 105 × 105/2000w =5.5w; therefore, a plurality of high-power resistors are required to be connected in parallel for the power-taking resistor, for example, 4 high-power resistors R3, R4, R9 and R15 are connected in parallel in fig. 1, so that the power consumption is large and the power efficiency is very low.

Disclosure of Invention

An object of the utility model is to provide a power starting circuit of wide range low-power consumption is used for solving the technical problem that above-mentioned exists.

In order to achieve the above purpose, the utility model adopts the technical scheme that: a power supply starting circuit with wide range and low power consumption is used for starting a power supply chip in the power supply circuit and comprises a power-taking resistor circuit, a switch circuit and a turn-off circuit, wherein the input end of the power-taking resistor circuit is used for being connected with a power supply, the output end of the power-taking resistor circuit is connected with the power supply end of the power supply chip, the switch circuit is used for controlling the on-off of the power-taking resistor circuit, and the switch circuit is configured to be in a conducting state when the power supply is input to the input end of the power-taking resistor circuit; the shutdown circuit is configured to control the switching circuit to be turned off when the output voltage of the power supply circuit reaches a set value.

Further, the power-taking resistor circuit comprises a power-taking resistor R1 and a diode D1, a first end of the power-taking resistor R1 is connected with an input end of the power-taking resistor circuit, a second end of the power-taking resistor R1 is connected with a positive end of the diode D1, and a negative end of the diode D1 is connected with a power supply end of the power supply chip.

Furthermore, the power-taking resistor circuit further comprises a voltage stabilizing diode Z1, the negative end of the voltage stabilizing diode Z1 is connected with the positive end of the diode D1, and the positive end of the voltage stabilizing diode Z1 is grounded.

Furthermore, the switching circuit is implemented by using an NPN transistor.

Furthermore, the switching circuit comprises an NPN triode Q7, a resistor R28 and a zener diode Z3, wherein a collector of the NPN triode Q7 is connected to the second end of the power taking resistor R1, an emitter of the NPN triode Q7 is connected to the positive end of the diode D1, a base of the NPN triode Q7 is connected to the output end of the turn-off circuit, a base of the NPN triode Q7 is connected to the input end of the power taking resistor circuit through the resistor R28, the zener diode Z3 is connected between the base of the NPN triode Q7 and the ground, and a zener value of the zener diode Z3 is greater than a zener value of the zener diode Z1.

Furthermore, the turn-off circuit is realized by adopting an NMOS tube.

Furthermore, the turn-off circuit comprises an NMOS transistor Q5, a resistor R26, a resistor R30, and a zener diode Z4, wherein a first end of the resistor R26 is connected to an auxiliary power supply of the power circuit for supplying power to the power chip, a second end of the resistor R26 is connected in reverse series to the zener diode Z4 and to the gate of the NMOS transistor Q5, a drain of the NMOS transistor Q5 is connected to the base of the NPN triode Q7, a source of the NMOS transistor Q5 is grounded, and the resistor R30 is connected between the gate of the NMOS transistor Q5 and ground.

Furthermore, the turn-off circuit further includes a capacitor C30, and the capacitor C30 is connected in parallel with the resistor R30.

The utility model also discloses a power supply circuit is equipped with foretell power starting circuit.

The utility model also discloses an electron device is equipped with foretell power supply circuit.

The utility model has the advantages of:

the utility model discloses a set up switch circuit and turn-off circuit, turn-off circuit is after power supply circuit starts, and control switch circuit turn-offs gets the electrical resistance return circuit, has wide range power supply input and low power dissipation's advantage.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a circuit diagram of a conventional flyback isolated power circuit and a power starting circuit thereof;

fig. 2 is a circuit diagram of a power supply start circuit according to an embodiment of the present invention.

Detailed Description

To further illustrate the embodiments, the present invention provides the accompanying drawings. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the embodiments. With these references, one of ordinary skill in the art will appreciate other possible embodiments and advantages of the present invention. Elements in the figures are not drawn to scale and like reference numerals are generally used to indicate like elements.

The present invention will now be further described with reference to the accompanying drawings and detailed description.

As shown in fig. 2, a wide-range low-power-consumption power supply starting circuit is used for starting a power supply chip in a power supply circuit, that is, the power supply chip needs a power supply starting circuit to perform pre-starting, the specific embodiment is a power supply chip U1 for starting a flyback isolation power supply circuit, and the flyback isolation power supply circuit may be various existing flyback isolation power supply circuits, such as the flyback isolation power supply circuit shown in fig. 1, but is not limited thereto, and in some embodiments, the flyback isolation power supply circuit may also be a power supply chip that needs to perform pre-starting in starting other power supply circuits.

The power supply starting circuit comprises a power-taking resistor circuit, a switch circuit and a turn-off circuit, wherein the input end of the power-taking resistor circuit is used for being connected with a power supply, the output end of the power-taking resistor circuit is connected with the power supply end VDD of the power supply chip U1, the switch circuit is used for controlling the on-off of the power-taking resistor circuit, and the switch circuit is configured to be in a conducting state when the power supply is input to the input end of the power-taking resistor circuit; the shutdown circuit is configured to control the switching circuit to be turned off when the output voltage of the power supply circuit reaches a set value.

In this embodiment, the power-taking resistor circuit includes a power-taking resistor R1 and a diode D1, a first end of the power-taking resistor R1 is connected to an input end of the power-taking resistor circuit, a second end of the power-taking resistor R1 is connected to a positive end of the diode D1, and a negative end of the diode D1 is connected to a power supply terminal VDD of the power supply chip U1.

In this embodiment, the input terminal of the POWER-taking resistor circuit includes a first input terminal AC-POWER and a second input terminal PV +, the first input terminal AC-POWER is connected in series with a diode D4, the first input terminal AC-POWER is used for connecting to the adapter input, and the second input terminal PV + is used for connecting to the photovoltaic input, but is not limited thereto.

In this embodiment, the power-taking resistor R1 is a resistor with a small resistance (e.g., 2k Ω), so that the low-voltage input (e.g., 11V) of the adapter can be normally started, thereby realizing wide-range power supply input.

Furthermore, in this embodiment, the power-taking resistor circuit further includes a zener diode Z1, a negative terminal of the zener diode Z1 is connected to a positive terminal of the diode D1, the positive terminal of the zener diode Z1 is grounded GND, and the zener diode Z1 is configured to limit the voltage of the power supply terminal VDD input to the power supply chip U1 from being too high, so as to protect the power supply chip U1 from being burned out, and improve stability and reliability.

Preferably, in this embodiment, the switching circuit is implemented by using an NPN transistor Q7, which has a low start voltage and is easily in a saturation conducting state, and is easily started when a low voltage is input, and is easy to implement and low in cost.

Specifically, the switching circuit comprises an NPN triode Q7, a resistor R28 and a zener diode Z3, wherein a collector of the NPN triode Q7 is connected to the second end of the power taking resistor R1, an emitter of the NPN triode Q7 is connected to the positive end of the diode D1, a base of the NPN triode Q7 is connected to the output end of the turn-off circuit, a base of the NPN triode Q7 is connected to the input end of the power taking resistor circuit through the resistor R28, the zener diode Z3 is connected between the base of the NPN triode Q7 and the ground GND, a zener value of the zener diode Z3 is greater than that of the zener diode Z1, and by setting a resistance value of the resistor R28, the NPN triode Q7 can be easily in a saturated conduction state and can be easily started when low voltage is input. Of course, in some embodiments, the switching circuit may be implemented using other switching circuits.

Preferably, in this embodiment, the turn-off circuit is implemented by using an NMOS transistor Q5, so that the start voltage is high, misconduction is not likely to occur, and the reliability is high.

Specifically, the turn-off circuit includes an NMOS transistor Q5, a resistor R26, a resistor R30, and a zener diode Z4, the first end of the resistor R26 is connected to an auxiliary power VCC of the flyback isolation power supply circuit, the auxiliary power VCC is connected to a power supply terminal VDD of the power supply chip U1 to provide a working power supply for the power supply chip U1, the second end of the resistor R26 is connected in series with the zener diode Z4 in reverse direction to the gate of the NMOS transistor Q5, the drain of the NMOS transistor Q5 (the output end of the turn-off circuit) is connected to the base of the NPN triode Q7, the source of the NMOS transistor Q5 is grounded GND, and the resistor R30 is connected between the gate of the NMOS transistor Q5 and the ground GND.

Furthermore, in this embodiment, the turn-off circuit further includes a capacitor C30, the capacitor C30 is connected in parallel with the resistor R30, and by setting the capacitor C30, not only the filtering function is achieved, but also the NMOS transistor Q5 is driven after a proper time delay, so that the turn-off of the switch circuit is more reasonable and reliable.

The utility model also discloses a power supply circuit is equipped with foretell power starting circuit, and is concrete, and power supply circuit is for swashing back formula isolation power supply circuit.

The working principle is as follows:

when the first input end AC-POWER has an adapter input and/or the second input end PV + has a photovoltaic input, the NPN triode Q7 is conducted, the adapter input and/or the photovoltaic input provide a starting POWER supply for the POWER supply chip U1 through the POWER taking resistor R1, the NPN triode Q7 and the diode D1, the POWER supply chip U1 is started, the flyback isolation POWER supply circuit starts to work, the POWER taking resistor R1 can adopt a resistor with a small resistance value, so that the adapter input (such as 11V) can also be normally started, and the wide-range POWER supply input is realized; when the flyback isolation power supply circuit is in normal operation, the output voltage reaches a set value, the voltage of the auxiliary power supply VCC can break down the zener diode Z4 to charge the capacitor C30, the NMOS tube Q5 is driven to be conducted after a certain time delay, the base of the NPN triode Q7 is pulled down, the NPN triode Q7 is disconnected, and therefore the power taking resistor loop is disconnected, the power taking resistor loop has no current, the power taking resistor R1 has no power consumption, the power consumption is reduced, the power supply efficiency is improved, the power taking resistor R1 cannot generate heat seriously, and only a common resistor is adopted.

The utility model also discloses an electron device is equipped with foretell power supply circuit, and is concrete, and electron device can be energy storage product, portable power supply etc..

The utility model discloses a set up switch circuit and turn-off circuit, turn-off circuit is after power chip starts, and control switch circuit turn-offs gets the electrical resistance return circuit, has wide range power supply input, advantage that the low power dissipation.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A power supply starting circuit with wide range and low power consumption is used for starting a power supply chip in the power supply circuit, and is characterized in that: the power supply chip comprises a power taking resistor circuit, a switching circuit and a turn-off circuit, wherein the input end of the power taking resistor circuit is used for being connected with a power supply, the output end of the power taking resistor circuit is connected with the power supply end of the power supply chip, the switching circuit is used for controlling the turn-on and turn-off of the power taking resistor circuit, and the switching circuit is configured to be in a conducting state when the power supply is input into the input end of the power taking resistor circuit; the shutdown circuit is configured to control the switching circuit to be turned off when the output voltage of the power supply circuit reaches a set value.

2. The wide range low power consumption power supply start-up circuit of claim 1, wherein: the power taking resistor circuit comprises a power taking resistor R1 and a diode D1, a first end of the power taking resistor R1 is connected with an input end of the power taking resistor circuit, a second end of the power taking resistor R1 is connected with the positive end of the diode D1, and the negative end of the diode D1 is connected with a power supply end of the power supply chip.

3. The wide range low power consumption power supply start-up circuit of claim 2, characterized in that: the power-taking resistor circuit further comprises a voltage stabilizing diode Z1, the negative end of the voltage stabilizing diode Z1 is connected with the positive end of the diode D1, and the positive end of the voltage stabilizing diode Z1 is grounded.

4. The wide range low power consumption power supply start-up circuit of claim 3, wherein: the switching circuit is realized by adopting an NPN triode.

5. The wide range low power consumption power supply start-up circuit of claim 4, wherein: the switching circuit comprises an NPN triode Q7, a resistor R28 and a voltage stabilizing diode Z3, wherein a collector of the NPN triode Q7 is connected with the second end of the power taking resistor R1, an emitter of the NPN triode Q7 is connected with the positive end of the diode D1, a base of the NPN triode Q7 is connected with the output end of the turn-off circuit, a base of the NPN triode Q7 is connected with the input end of the power taking resistor circuit through the resistor R28, the voltage stabilizing diode Z3 is connected between the base of the NPN triode Q7 and the ground, and the voltage stabilizing value of the voltage stabilizing diode Z3 is larger than that of the voltage stabilizing diode Z1.

6. The wide range low power consumption power supply start-up circuit of claim 5, wherein: the turn-off circuit is realized by adopting an NMOS tube.

7. The wide range low power consumption power supply start-up circuit of claim 6, characterized in that: the turn-off circuit comprises an NMOS (N-channel metal oxide semiconductor) tube Q5, a resistor R26, a resistor R30 and a voltage stabilizing diode Z4, wherein the first end of the resistor R26 is connected with an auxiliary power supply of the power circuit for supplying power to the power chip, the second end of the resistor R26 is connected with the grid electrode of the NMOS tube Q5 in series in a reverse direction, the drain electrode of the NMOS tube Q5 is connected with the base electrode of an NPN (negative-positive-negative) triode Q7, the source electrode of the NMOS tube Q5 is grounded, and the resistor R30 is connected between the grid electrode of the NMOS tube Q5 and the ground.

8. The wide range low power consumption power supply start-up circuit of claim 7, wherein: the turn-off circuit further comprises a capacitor C30, and the capacitor C30 is connected in parallel with the resistor R30.

9. A power supply circuit, characterized by: a power supply startup circuit as claimed in any one of claims 1 to 8 is provided.

10. An electronic device, characterized in that: there is provided the power supply circuit as claimed in claim 9.