CN215116366U

CN215116366U - A Fixture for Verifying the Electrical Stress Tolerance of Power PWM Chips

Info

Publication number: CN215116366U
Application number: CN202120672789.0U
Authority: CN
Inventors: 陈晨
Original assignee: Taicang T&W Electronics Co Ltd
Current assignee: Taicang T&W Electronics Co Ltd
Priority date: 2021-04-01
Filing date: 2021-04-01
Publication date: 2021-12-10
Anticipated expiration: 2031-04-01

Abstract

The utility model discloses a fixture for verifying the electrical stress tolerance of a PWM chip of a power supply, comprising a PCB board. The PCB board is provided with a PWM chip pin seat, a first terminal, a second terminal and a third terminal. There are one-pin interface, two-pin interface, three-pin interface, four-pin interface, five-pin interface, six-pin interface, seven-pin interface and eight-pin interface on the seat. The rear ground, the five-pin interface and the six-pin interface are connected to the second terminal, the seven-pin interface and the eight-pin interface are grounded, and an adjustable capacitor CX and an adjustable resistance RX are connected in series between the third terminal and the second terminal. By changing the resistance and capacitance values, it is verified whether the PWM chip can work normally in different states. In this way, the parameters of the electrical stress of the PWM chip can be verified. It is easy to implement, and can verify the electrical stress of different PWM chips, and obtain which resistance and capacitance values cannot work normally. This solution is low in cost and highly cost-effective.

Description

Clamp for verifying electric stress tolerance of power supply PWM chip

Technical Field

The utility model relates to a chip test technical field especially relates to a verify anchor clamps of power PWM chip electric stress tolerance limit.

Background

In order to ensure that the PWM chip can normally work, verification under different environments is required, for example, extreme environments such as high temperature and low temperature are required, the normal verification cannot be carried out, thinking needs to be changed, differences caused under the extreme environments are replaced by a certain mode, verification is carried out by adjusting an adjustable resistor and a capacitor, and whether the PWM chip can normally work under different states can be verified through the mode.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a verify power PWM chip electric stress tolerance's anchor clamps to the not enough of above-mentioned prior art. Whether the PWM chip can normally work in different states or not is verified by changing the resistance and the capacitance, and the parameters of the electrical stress of the PWM chip can be verified by the mode.

In order to solve the above problems, the utility model adopts the following technical proposal:

the utility model provides a verify anchor clamps of power PWM chip electric stress tolerance, includes the PCB board, be equipped with PWM chip pin seat, first terminal, second terminal and third terminal on the PCB board, be equipped with a foot interface, two foot interfaces, tripod interface, four-foot interface, five foot interfaces, six foot interfaces, seven foot interfaces, eight foot interfaces on the PWM chip pin seat, a foot interface links to each other with first terminal, ground connection behind four foot interface series resistance R1, five foot interfaces and six foot interfaces link to each other with the second terminal, seven foot interfaces and eight foot interface ground connection, it has adjustable capacitance CX and adjustable resistance RX to establish ties between third terminal and the second terminal.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in: whether the PWM chip can normally work in different states or not is verified by changing the resistance and the capacitance, and the parameters of the electrical stress of the PWM chip can be verified by the mode. The method is easy to realize, can verify the electric stress of different PWM chips, and can not work normally under any resistance-capacitance value, and the scheme has low cost and high cost performance.

Drawings

Fig. 1 is a schematic sectional structure of the weather strip.

In the figure: 1. a pin interface; 2. a two-pin interface; 3. a three-pin interface; 4. a four-pin interface; 5. a five-pin interface; 6. a six-pin interface; 7. a seven-pin interface; 8. an eight-pin interface; 9. a PCB board; 10. a PWM chip pin base; 11. a first terminal; 12. a second terminal; 13. and a third terminal.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings and examples. The following examples are intended to illustrate the invention, but are not intended to limit the scope of the invention.

As shown in fig. 1, a verify anchor clamps of power PWM chip electric stress tolerance for verify that power PWM chip can normally work under the state of difference, including PCB board 9, be equipped with PWM chip pin seat 10, first terminal 11, second terminal 12 and third terminal 13 on the PCB board 9, be equipped with a foot interface 1 on the PWM chip pin seat 10, two foot interface 2, three-pin interface 3, four-pin interface 4, five-pin interface 5, six-pin interface 6, seven foot interface 7, eight-pin interface 8, a foot interface 1 links to each other with first terminal 11, ground connection behind the 4 series resistance R1 of four-pin interface, five foot interface 5 and six-pin interface 6 link to each other with second terminal 12, seven foot interface 7 and eight-pin interface 8 ground connection, it has adjustable electric capacity CX and adjustable resistance RX to establish ties between third terminal 13 and the second terminal 12.

The working principle is as follows: 1. the model of the PWM chip used in the present embodiment is OB 2535E. The high-current amplifier is characterized by comprising 8 pins in total, wherein pin 1 is VDD and is supplied by an external voltage source, pins 2 and 3 are used for compensation and feedback respectively, pin 4 is a CS pin and is used for detecting current and is grounded through a resistor R1, pins 5 and 6 are DRAIN (DRAIN stage) and are connected together for conducting through-current and switching of large current, and pin 7 and pin 8 are GND. 2. The voltage source is used as a voltage input, is connected with the first terminal 11, and is used for supplying power to pin 1 of the chip and electrifying and working the chip. 3. The PWM chip pin holder 10 is used to solder a PWM chip to be tested thereon for verification. 4. The adjustable capacitor CX and the adjustable resistor RX are variable resistors and variable capacitors and are connected in series between a third terminal 13 and a second terminal 12, the second terminal 12 is connected to the negative electrode of the external transformer, and the third terminal 13 is connected to the positive electrode of the external transformer and used for filtering reverse voltage caused by leakage inductance of the transformer, so that voltage overshoot generated on a drain of a PWM chip is reduced, and the PWM chip is prevented from being burnt.

When the clamp is used for verification, firstly, a PWM chip is welded on a PWM chip pin base 10, at the moment, a voltage source supplies power to a chip power supply pin, the PWM chip starts working, a switching action is generated on a chip drain, overshoot is caused on a chip drain voltage due to reverse voltage caused by transformer leakage inductance, at the moment, an adjustable capacitor CX and an adjustable resistor RX are required to be adjusted, the electric stress caused by the voltage overshoot is reduced to the minimum, the adjustable resistor RX is adjusted to be 100 ohms, the adjustable capacitor CX is 10uf, at the moment, the voltage overshoot can be seen by observing a voltage waveform through an oscilloscope, the electric stress is large for the PWM chip drain, the adjustable capacitor CX and the adjustable resistor RX are required to be adjusted again, the adjustable resistor RX is adjusted to be 200 ohms, the adjustable capacitor CX is 100uf, at the moment, the voltage overshoot can be seen by observing the voltage waveform, the electric stress is still a little large for the PWM chip drain, and finally, the adjustable resistor RX is adjusted to be 500 ohms, the adjustable capacitor CX is 200uf, at the moment, voltage overshoot can be seen only to be 50V by observing the voltage waveform, the electrical stress for the leakage of the PWM chip meets the requirement, and the method is safe and reliable within the limitation of the use range. The scheme is simple to realize, the cost is saved, the cost of the clamp plate is only dozens of money, and the operation is convenient.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention.

Claims

1. a clamp for verifying power supply PWM chip electrical stress tolerance, is characterized in that, comprises PCB board (9), and described PCB board (9) is provided with PWM chip pin seat (10), first terminal ( 11), the second terminal (12) and the third terminal (13), the PWM chip pin socket (10) is provided with a one-pin interface (1), a two-pin interface (2), a three-pin interface (3), Four-pin port (4), five-pin port (5), six-pin port (6), seven-pin port (7), eight-pin port (8), the one-pin port (1) and the first terminal (11) The four-pin interface (4) is connected to the ground after being connected in series with the resistor R1, the five-pin interface (5) and the six-pin interface (6) are connected with the second terminal (12), and the seven-pin interface (7) and the eight-pin interface (7) are connected to the second terminal (12). The pin interface (8) is grounded, and an adjustable capacitor CX and an adjustable resistor RX are connected in series between the third terminal (13) and the second terminal (12).