CN217721019U

CN217721019U - Multi-stage heavy-current transistor with built-in resistor and control chip power supply system

Info

Publication number: CN217721019U
Application number: CN202221318301.5U
Authority: CN
Inventors: 许如柏; 彭里; 黄冲; 黄裕泉
Original assignee: Huimang Microelectronics Shenzhen Co ltd
Current assignee: Huimang Microelectronics Shenzhen Co ltd
Priority date: 2022-05-27
Filing date: 2022-05-27
Publication date: 2022-11-01
Anticipated expiration: 2032-05-27

Abstract

A multi-stage high-current transistor with built-in resistor and control chip power supply system, the high-current transistor includes built-in resistor and cascaded transistors, and also provides the following terminals as connection terminals with external circuit: a plurality of base connection ends, a collector connection end and an emitter connection end, the number of which is consistent with that of the triodes; the first end of the built-in resistor is connected with the base electrode of a first triode, the base electrode of each triode is used as a base electrode connecting end, the emitting electrode of the former triode is connected with the base electrode of the latter triode, the emitting electrode of the last triode is used as the emitting electrode connecting end, and the collector electrodes of all the triodes and the second end of the built-in resistor are connected together to be used as the collector electrode connecting end; the utility model can realize the fast switching-off of the transistor; when the chip power supply system is applied, the VCC starting charging function of the chip can be realized by using the built-in resistor instead of the starting resistor.

Description

Multi-stage heavy-current transistor with built-in resistor and control chip power supply system

Technical Field

The utility model relates to an electronic circuit technical field especially relates to a multistage type heavy current transistor and control chip power supply system of built-in resistance.

Background

The large-current transistor is mainly applied to power driving, can be flexibly applied to the field of high-power management by matching the technology with a control chip, greatly saves the BOM cost of a system, and has wide applicability. Referring to fig. 1, a control chip power supply system in the prior art is composed of a start resistor Rst, a VCC capacitor, an Equivalent Series Resistance (ESR) R1 of the VCC capacitor, and the like. The working principle is that when a power supply system is started, a VCC capacitor is charged through a starting resistor Rst, at the moment, a chip is in a shutdown state, and when the voltage of Vcc rises to a certain voltage set in a controller, the chip is controlled to start working.

One form of the large current transistor is a two-stage structure, as shown in fig. 2, (a) and (b) in the figure respectively show a multi-stage large current transistor composed of two NPN-type and two PNP-type transistors, and the multi-stage large current transistor includes a front-stage transistor and a rear-stage transistor, an emitter of the front-stage transistor is connected to a base of the rear-stage transistor, and a collector of the front-stage transistor is connected to a collector of the rear-stage transistor. The existing multistage type heavy current transistor only has 3 pins, as shown in C, B and E in the figure, a drive circuit turns off the multistage type heavy current transistor, only a first stage triode can be turned off, because the triode has the characteristic of time delay of turn-off storage time, the turn-off of a second stage is very slow, the current caused by turn-off time delay is too large during high-voltage heavy current, risks such as accidents are easy to occur, and the longer the turn-off time delay, the worse the efficiency, the higher the risk. For this reason, it is common in the prior art to have a resistor between the base and emitter of each of the two transistors, and by increasing this resistor, the switching speed of the latter transistor can be slightly increased, but it still does not achieve a good effect.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model lies in, slow, the supply circuit need dispose special starting resistance's defect to prior art's above-mentioned switch response speed, provide a multistage type heavy current transistor and control chip power supply system of built-in resistance, it not only can realize very fast switch response speed, can utilize built-in resistance wherein to replace starting resistance to realize VCC start-up charging function when using in the control chip power supply system moreover.

The utility model provides a technical scheme that its technical problem adopted is:

in one aspect, a multi-stage high-current transistor with a built-in resistor is constructed, which includes a built-in resistor and a plurality of cascaded transistors, and the following terminals are also provided as connection terminals with an external circuit: a plurality of base connection ends, a collector connection end and an emitter connection end, the number of which is consistent with that of the triodes;

the first end of the built-in resistor is connected with the base of the first triode, the base of each triode is used as the base connecting end, the emitting electrode of the former triode is connected with the base of the latter triode, the emitting electrode of the last triode is used as the emitting electrode connecting end, and the collecting electrodes of all the triodes and the second end of the built-in resistor are connected together to be used as the collecting electrode connecting end.

In the multi-stage high-current transistor with the built-in resistor of the present invention, the built-in resistor is a diffusion resistor or a polysilicon resistor.

In the multi-stage heavy-current transistor with the built-in resistor, the plurality of triodes are all NPN-type triodes or PNP-type triodes.

The multistage type heavy current transistor of built-in resistance in, still include the diode, the positive pole of diode is connected with the projecting pole of last triode, the negative pole of diode is connected with the collecting electrode of last triode.

In a second aspect, a control chip power supply system is constructed, which includes a VCC capacitor, a primary winding, and the aforementioned multi-stage high-current transistor;

the control chip comprises a VCC pin and at least one transistor control pin, wherein one transistor control pin is used as a transistor main control pin, the transistor main control pin is connected to the anode of a middle diode, the cathode of the middle diode is connected to the VCC pin, the first base connecting end of the multistage high-current transistor is connected with the transistor main control pin, one end of a primary winding is connected to an external input power supply, the other end of the primary winding is connected with the collector connecting end of the multistage high-current transistor, the emitter connecting end of the multistage high-current transistor is grounded, a VCC capacitor is connected between the VCC pin and the ground, and the VCC capacitor is used for charging through the built-in resistor when a power supply system is started.

The utility model discloses a multistage type heavy current transistor and control chip power supply system of built-in resistance has following beneficial effect: the transistor amplification factor of the utility model is equal to multiplication of all levels, high current output can be obtained at the last level, the first level driving current can be controlled to be very small, each triode can lead out a base connecting end, several base connecting ends can be flexibly selected according to actual application requirements for control, the control main core matched with multi-level drive can realize full coverage of application of different current outputs, and can realize quick turn-off of the transistor, thereby solving the problem of slow response speed of a switch; when the circuit is applied to a control chip power supply system, the VCC starting charging function of the chip can be realized by using the built-in resistor instead of the starting resistor, so that a peripheral starting resistor is omitted.

Drawings

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

FIG. 1 is a schematic diagram of a high current transistor applied to a power supply system of a control chip;

FIG. 2 is a schematic diagram of a conventional two-stage high current transistor;

fig. 3 is a schematic structural diagram of a first embodiment of the multistage high-current transistor of the present invention;

fig. 4 is a schematic structural diagram of a second embodiment of the multi-stage high-current transistor of the present invention;

fig. 5 is a schematic structural diagram of the control chip power supply system of the present invention.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully hereinafter with reference to the accompanying drawings. Exemplary embodiments of the present invention are shown in the drawings. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete. It should be understood that the embodiments and specific features in the embodiments of the present invention are detailed description of the technical solutions of the present invention, and are not limited to the technical solutions of the present invention, and the technical features in the embodiments and the embodiments of the present invention may be combined with each other without conflict.

Example one

Referring to fig. 3, the multi-stage high-current transistor with a built-in resistor of the present embodiment includes a built-in resistor Rcb and a plurality of cascaded transistors, as shown in the figure, a total of n transistors T1 to Tn, where n is an integer greater than 1, such as 2, 3, and 4. The high-current transistor also provides the following terminals as connection terminals with an external circuit: a plurality of base connection terminals B1-Bn, a collector connection terminal C and an emitter connection terminal E, the number of which is consistent with that of the triodes.

The first end of the built-in resistor Rcb is connected with the base electrode of the first triode T1, the base electrode of each triode is used as the base electrode connecting end, the emitting electrode of the former triode is connected with the base electrode of the latter triode, the emitting electrode of the last triode Tn is used as the emitting electrode connecting end E, and the collector electrodes of all the triodes T1-Tn and the second end of the built-in resistor Rcb are connected together to be used as the collector electrode connecting end C.

Preferably, a diode D may be further provided according to circumstances, wherein an anode of the diode D is connected to an emitter of the last transistor Tn, and a cathode of the diode D is connected to a collector of the last transistor Tn.

Specifically, the built-in resistor Rcb is a diffusion resistor or a polysilicon resistor.

In this embodiment, all of the transistors T1 to Tn are NPN transistors, so that the finally formed multi-stage heavy-current transistor is equivalent to an NPN transistor.

The structure of the embodiment can be compatibly integrated by any triode process (processes such as npn/pnp/vertical structure transistor/transverse structure transistor/high voltage/low voltage and the like), different design requirements are realized by a layout design method, any change in the process is not needed, the research and development period is shortened, and the production difficulty is reduced.

The amplification factor of the large-current transistor of the embodiment is equal to the multiplication of the amplification factors of the triodes T1-Tn at each stage. The n-level NPN triodes T1-Tn are cascaded, so that the output of a large current is ensured while high withstand voltage is met, and the driving current is smaller. The base electrode of each stage of NPN triode is connected to provide a base electrode connecting end, the base electrode connecting ends led out by certain NPN triodes are flexibly selected according to practical application, and the multistage driving control main core is matched to realize full coverage of different current output applications. The extraction of the base connection ends also solves the problem of low turn-off delay response speed inherent in the conventional two-stage transistor, greatly reduces turn-off delay and improves system efficiency; has higher reliability. The advantages of this embodiment are more apparent as the number of stages, i.e., n, is larger.

Moreover, the embodiment adds a built-in resistor Rcb between C and B1, and the resistor Rcb can replace a peripheral resistor device, so that the cost of the scheme is saved. As shown in fig. 5, the control chip power supply system applied in this embodiment includes a VCC capacitor C1, a freewheeling diode D1, a primary winding of a transformer, an auxiliary winding of the transformer, and the aforementioned multi-stage high-current transistor, where R1 represents an Equivalent Series Resistance (ESR) of the VCC capacitor C1.

The control chip comprises a VCC pin and at least one transistor control pin, wherein one transistor control pin is used as a transistor main control pin, the transistor main control pin is connected to the anode of a middle diode, the cathode of the middle diode is connected to the VCC pin, the first base connecting end of the multistage high-current transistor is connected with the transistor main control pin, one end of a primary winding is connected to an external input power source Vin, the other end of the primary winding is connected with a collector connecting end C of the multistage high-current transistor, an emitter connecting end E of the multistage high-current transistor is grounded, one end of an auxiliary winding is grounded, the other end of the auxiliary winding is connected with the anode of a freewheeling diode D1, the cathode of the freewheeling diode D1 is connected with the VCC pin, and a VCC capacitor C1 is connected between the VCC pin and the ground.

The VCC capacitor C1 is used for charging through the built-in resistor Rcb when a power supply system is started, and the chip is in a shutdown state at the moment; when the voltage of Vcc rises to a certain voltage set in the chip, the chip starts to work and starts to drive the multistage type heavy-current transistor, and the power supply during working is realized by an auxiliary winding. Thus, the built-in resistor Rcb of the embodiment can replace the conventional peripheral starting resistor Rst to realize the VCC starting charging function of the chip, so that the peripheral starting resistor Rst is omitted.

Example two

Referring to fig. 4, the difference from the first embodiment is that all the transistors in the first embodiment are PNP transistors, so that the finally formed multi-stage high-current transistor is equivalent to a PNP transistor.

To sum up, the utility model discloses a multistage type heavy current transistor and control chip power supply system of built-in resistance has following beneficial effect: the transistor amplification factor of the utility model is equal to multiplication of all levels, high current output can be obtained at the last level, the first level driving current can be controlled to be very small, each triode can lead out a base connecting end, several base connecting ends can be flexibly selected according to actual application requirements for control, the control main core matched with multi-level drive can realize full coverage of application of different current outputs, and can realize quick turn-off of the transistor, thereby solving the problem of slow response speed of a switch; when the power supply system is applied to a control chip power supply system, the VCC starting charging function of the chip can be realized by using the built-in resistor to replace a starting resistor, so that a peripheral starting resistor is omitted.

It is noted that the term "coupled" or "connected" as used herein includes not only the direct coupling of two entities, but also the indirect coupling via other entities with beneficial and improved effects. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The terms "first", "second", and the like, including ordinal numbers, used in the present specification may be used to describe various components, but the components are not limited by the terms. These terms are used only for the purpose of distinguishing one constituent element from other constituent elements. For example, a first component may be termed a second component, and, similarly, a second component may be termed a first component, without departing from the scope of the present invention.

The embodiments of the present invention have been described with reference to the accompanying drawings, but the present invention is not limited to the above embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the scope of the present invention, and these forms are all within the protection scope of the present invention.

Claims

1. A multi-stage high-current transistor with a built-in resistor is characterized by comprising the built-in resistor and a plurality of cascaded triodes, and the following terminals are also provided as connecting ends with an external circuit: a plurality of base connection ends, a collector connection end and an emitter connection end, the number of which is consistent with that of the triodes;

2. The multi-stage high-current transistor with built-in resistor of claim 1, wherein the built-in resistor is a diffused resistor or a polysilicon resistor.

3. The multi-stage high-current transistor with built-in resistor of claim 1, wherein all of the plurality of transistors are NPN transistors or all of the plurality of transistors are PNP transistors.

4. The multi-stage high-current transistor with built-in resistor of claim 1, further comprising a diode, wherein the anode of the diode is connected to the emitter of the last transistor, and the cathode of the diode is connected to the collector of the last transistor.

5. A control chip power supply system is characterized by comprising a VCC capacitor, a primary winding of a transformer and a multi-stage high-current transistor according to any one of claims 1-4;