CN215072163U

CN215072163U - Novel compensation intermittent working circuit based on bridge topology

Info

Publication number: CN215072163U
Application number: CN202121222317.1U
Authority: CN
Inventors: 张鹏; 何永明
Original assignee: Hunan Megmit Electric Technology Co ltd
Current assignee: Hunan Megmit Electric Technology Co ltd
Priority date: 2021-06-02
Filing date: 2021-06-02
Publication date: 2021-12-07
Anticipated expiration: 2031-06-02

Abstract

The utility model discloses a novel compensation intermittent type work circuit based on bridge topology, including half-bridge circuit and chip, the voltage and the LLC-COM feedback voltage of the sampling point of half-bridge circuit add and with the SKIP/DISABLE foot switch-on of chip, the sampling point of half-bridge circuit is located between upper portion transistor Q1 and lower part transistor Q2. The utility model discloses a based on novel compensation intermittent type work circuit of bridge type topology has simple structure, convenient to use, sends out advantages such as ripples improvement circuit reliability and extension parts life through the symmetry.

Description

Novel compensation intermittent working circuit based on bridge topology

Technical Field

The utility model relates to a compensation circuit technical field especially relates to a novel compensation intermittent type work circuit based on bridge type topology.

Background

As shown in FIG. 1, a typical half-bridge LLC topology compensation intermittent operation circuit is provided, and under normal operation, the DRVL drive square wave level of a lower transistor Q4 of a half bridge is superposed to an SKIP/DISABLE pin through a transistor D2 and a resistor R23 with an LLC-COM level from feedback; and the filter is filtered by using a capacitor C9, and the voltage of the resistor R18 is divided and adjusted. The LLC-COM feedback level is variable according to load and is highest when no load exists. When the level of the SKIP/DISABLE pin exceeds an amplitude value, the drive is switched off, and when the level is reduced to an amplitude value, the drive is switched on, namely, the intermittent operation is carried out.

The DRVL lower tube is introduced to drive a square wave level, namely a feedback level is introduced, the load condition is reflected, and the adjusting resistor R23 reduces the number of switches in a period, so that no-load loss is reduced. However, only the DRVL down tube driving condition is introduced, and the test result is shown in fig. 2, in a period, the wave generation of the upper and lower tubes is asymmetric (the upper tube Q3 is a gray line, and the lower tube Q4 is a black line), so that the output ripple is irregular, the main circuit working condition cannot be actually reflected, the module no-load ripple is difficult to adjust to a value meeting the specification requirement, and the transformer is magnetically biased to be saturated when abnormal large currents such as short circuit and the like are output, and the switching MOS tube is damaged.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to overcome prior art not enough, provide a simple structure, convenient to use, send out ripples improvement circuit reliability and extension parts life's novel compensation intermittent type work circuit based on bridge type topology through the symmetry.

In order to solve the technical problem, the utility model provides a technical scheme does:

a novel compensation intermittent working circuit based on a bridge topology comprises a half-bridge circuit and a chip, wherein voltage of a sampling point of the half-bridge circuit is superposed with LLC-COM feedback voltage and is connected with an SKIP/DISABLE pin of the chip, and the sampling point of the half-bridge circuit is located between an upper transistor Q1 and a lower transistor Q2.

As a further improvement of the above technical solution:

and a plurality of sampling resistors are connected to the sampling points.

And a first filtering module is arranged between the sampling point and a superposition point communicated with the LLC-COM, the first filtering module comprises a resistor R14 and a capacitor C5 which are connected in parallel, one end of the first filtering module is grounded, and the other end of the first filtering module is connected between the sampling point and the superposition point.

The first filtering module further comprises a diode D1 connected in parallel with the resistor R14 and the capacitor C5, and the anode of the diode D1 is grounded.

And a voltage division resistor R12 is arranged between the first filtering module and the superposition point.

A second filtering module is arranged between the superposition point and the SKIP/DISABLE pin and comprises a resistor R8 and a capacitor C3 which are connected in parallel, one end of the second filtering module is grounded, and the other end of the second filtering module is connected between the superposition point and the SKIP/DISABLE pin.

And a voltage division resistor R9 is arranged between the second filtering module and the superposition point.

Compared with the prior art, the utility model has the advantages of:

the utility model discloses a based on novel compensation intermittent type work circuit of bridge topology, including half-bridge circuit and chip, the voltage and LLC-COM feedback voltage of the sampling point of half-bridge circuit add and with the SKIP/DISABLE foot switch-on of chip, the sampling point of half-bridge circuit is located between upper portion transistor Q1 and lower part transistor Q2. The utility model discloses compensate in half-bridge circuit's midpoint sampling, owing to gather from half-bridge circuit's midpoint, the actual condition of upper and lower pipe work is truly reflected, and the upper and lower pipe drive has all been gathered that is to say, so let upper portion transistor Q1 and lower part transistor Q2 realize the symmetry through this compensation level and send out the ripples, the intermittent time is fixed, and the unloaded ripple of output main power reaches a more relatively stable even value, increases the reliability of circuit, and compared with the mode that current conventional compensation circuit only introduced the lower pipe compensation, the utility model discloses can realize regular output ripple through adjusting the compensation level, low no-load power consumption can solve the high ripple noise when some customer ends use the power, the problem that no-load power consumption exceeds standard; the problem that a switch MOS tube is damaged due to bias saturation of a transformer when abnormal large current such as short circuit of power output is avoided, the service life of components is prolonged, and the power supply can stably work under the limit condition. The circuit can be well applied to industrial products such as textile machine power supplies and the like and products such as communication products and the like.

Drawings

FIG. 1 is a schematic diagram of a typical half-bridge LLC topology compensated intermittent operation circuit;

FIG. 2 is a graph of test results for the circuit of FIG. 1;

fig. 3 is a schematic structural diagram of the novel compensation intermittent operating circuit based on the bridge topology;

FIG. 4 is a graph of test results for the circuit shown in FIG. 3;

fig. 5 is a graph of the output ripple of the circuit shown in fig. 3.

Illustration of the drawings: 1. a half-bridge circuit; 11. sampling points; 2. a chip; 3. overlapping points; 4. a first filtering module; 5. and a second filtering module.

Detailed Description

In order to facilitate understanding of the present invention, the present invention will be described more fully and specifically with reference to the accompanying drawings and preferred embodiments, but the scope of the present invention is not limited to the following specific embodiments.

Example (b):

as shown in fig. 3, the novel compensation intermittent operation circuit based on bridge topology of this embodiment includes a half-bridge circuit 1 and a chip 2, wherein the voltage at sampling point 11 of the half-bridge circuit 1 is superimposed with the LLC-COM feedback voltage and is connected to SKIP/DISABLE pin of the chip 2, and the sampling point 11 of the half-bridge circuit 1 is located between an upper transistor Q1 and a lower transistor Q2.

That is, the present embodiment compensates for the midpoint sampling of the half-bridge circuit 1, since the midpoint sampling is collected from the half-bridge circuit 1, the actual situation of the upper and lower tubes is reflected, that is, the upper and lower tube drives are collected, therefore, the compensation level enables the upper transistor Q1 and the lower transistor Q2 to realize symmetrical wave generation, the intermittent time is fixed, the output main power no-load ripple wave reaches a relatively stable and uniform value, the reliability of the circuit is increased, as shown in fig. 4, the test result shows that the upper transistor Q1 is a gray line, and the lower transistor Q2 is a black line, compared to the conventional compensation circuit that only introduces the lower tube compensation, this embodiment can achieve regular output ripple, low idle power consumption, the problems of high ripple noise and excessive no-load power consumption when some clients use power supplies can be solved, as shown in fig. 5; the problem that a switch MOS tube is damaged due to bias saturation of a transformer when abnormal large current such as short circuit of power output is avoided, the service life of components is prolonged, and the power supply can stably work under the limit condition. The circuit can be well applied to industrial products such as textile machine power supplies and the like and products such as communication products and the like, similar bridge circuits can achieve excellent compensation effects by applying the circuit, and meanwhile, the circuit is utilized to achieve loop stability and main circuit reliability improvement.

The circuit of the embodiment is simple, redundant circuits are not required to be added, the cost is economic, the reliability is high, and the power supply module is particularly suitable for power supply modules with high power ripples, relatively high requirements for relative ratio and output short circuits without constant current.

In this embodiment, as shown in fig. 3, a sampling resistor R3, a sampling resistor R4, a sampling resistor R5, and a sampling resistor R6 are connected in series at the sampling point 11 in order to obtain a compensation level.

In this embodiment, a first filtering module 4 is disposed between the sampling point 11 and the superposition point 3 connected to the LLC-COM, the first filtering module 4 includes a resistor R14 and a capacitor C5 connected in parallel, one end of the first filtering module 4 is grounded, and the other end is connected to a connection line between the sampling point 11 and the superposition point 3. The compensation level taken from the sampling point 11 is divided by a resistor R14 and then first order filtered by a resistor R14 and a capacitor C5 to filter out circuit noise and smooth the voltage.

In this embodiment, the first filter module 4 further includes a diode D1 connected in parallel with the resistor R14 and the capacitor C5, the anode of the diode D1 is grounded, and the diode D1 disposed at this position can play a role of clamping, so as to prevent the chip 2 from being damaged by the negative voltage generated by the circuit.

In this embodiment, a voltage dividing resistor R12 is disposed at a connection line between the first filtering module 4 and the superposition point 3, a second filtering module 5 is disposed between the superposition point 3 and the SKIP/DISABLE pin, the second filtering module 5 includes a resistor R8 and a capacitor C3 connected in parallel, one end of the second filtering module 5 is grounded, and the other end is connected to the connection line between the superposition point 3 and the SKIP/DISABLE pin. A voltage dividing resistor R9 is arranged at a connection between the second filtering module 5 and the superposition point 3. The voltage filtered by the first filtering module 4 passes through a voltage dividing resistor R12, is superposed with LLC-COM feedback voltage passing through a voltage dividing resistor R9, is divided by a resistor R8, is filtered by a resistor R8 and a capacitor C3, and finally reaches a SKIP/DISABLE pin, so that a stable compensation level is provided for the SKIP/DISABLE pin.

The above description is only the preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, the modifications and changes obtained without departing from the technical idea of the present invention should be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a novel compensation intermittent type work circuit based on bridge topology, includes half-bridge circuit (1) and chip (2), the voltage and the LLC-COM feedback voltage superposition of the sampling point (11) of half-bridge circuit (1) and with the SKIP/DISABLE foot switch-on of chip (2), its characterized in that: the sampling point (11) of the half bridge circuit (1) is located between the upper transistor Q1 and the lower transistor Q2.

2. The bridge topology based novel compensated intermittent operation circuit of claim 1, wherein: and a plurality of sampling resistors are connected to the sampling points (11).

3. The bridge topology based novel compensated intermittent operation circuit of claim 1, wherein: a first filtering module (4) is arranged between the sampling point (11) and the superposition point (3) communicated with the LLC-COM, the first filtering module (4) comprises a resistor R14 and a capacitor C5 which are connected in parallel, one end of the first filtering module (4) is grounded, and the other end of the first filtering module is connected between the sampling point (11) and the superposition point (3).

4. The bridge topology based novel compensated intermittent operation circuit of claim 3, wherein: the first filtering module (4) further comprises a diode D1 connected in parallel with the resistor R14 and the capacitor C5, and the anode of the diode D1 is grounded.

5. The bridge topology based novel compensated intermittent operation circuit of claim 3, wherein: a voltage division resistor R12 is arranged between the first filtering module (4) and the superposition point (3).

6. The bridge topology based novel compensated intermittent operation circuit of claim 3, wherein: a second filtering module (5) is arranged between the superposition point (3) and the SKIP/DISABLE pin, the second filtering module (5) comprises a resistor R8 and a capacitor C3 which are connected in parallel, one end of the second filtering module (5) is grounded, and the other end of the second filtering module is connected between the superposition point (3) and the SKIP/DISABLE pin.

7. The bridge topology based novel compensated intermittent operation circuit of claim 6, wherein: a voltage division resistor R9 is arranged between the second filtering module (5) and the superposition point (3).