Detection and identification of IC Electronics: a method for measuring the quality of analog power chip

Date：2021-11-30 11:29:52Views：2376

Power management chip is widely used in household appliances, mobile phones and tablets, industrial control equipment and other fields. It is the power supply heart of all electronic equipment. It controls the pulse of electronic equipment - electric energy, and is responsible for the functions of electric energy conversion, distribution and detection. Once it fails, it will directly cause the electronic equipment to stop working or even damage. It is a key device in electronic equipment. If the power chip is damaged in the circuit, it will cause the electronic equipment to stop working. For the detection and identification of IC electronics, let's understand the quality measurement method of the power chip in the power circuit.

1. Offline detection:Measure the positive and negative resistance values between the pins of the IC chip and the ground, and compare them with a good IC chip to find the fault point;

2. Online detection:The detection method of DC resistance is the same as that of off-line detection. But note: disconnect the power supply on the circuit board to be tested, the internal voltage of the multimeter shall not be greater than 6V, and pay attention to the influence of the periphery during measurement;

3. AC working voltage test method:Use a universal meter with DB gear to measure the approximate value of AC voltage on the chip. If there is no DB gear, a 0.1-0.5 can be connected in series with the positive probe μ F isolated DC capacitor. This method is suitable for IC with low working frequency. However, it should be noted that these signals will be affected by natural frequency and different waveforms, so the measured data is approximate.

4. Total current measurement method:By measuring the total current of the power chip, we can judge the quality of the chip. Due to the DC coupling inside the chip, when the IC is damaged (such as PN junction breakdown or open circuit), it will cause the later stage saturation and cut-off, and change the total current. Therefore, measuring the total current can judge the quality of the chip. The current value can be calculated by measuring the voltage on the loop resistance on line.

Before testing the power chip, we need to master the purpose, internal structure principle and main electrical characteristics of the IC in the circuit, and analyze the internal electrical schematic diagram when necessary, so as to better judge and prove whether the device is damaged. Through the above detection methods, engineers can quickly judge the quality of the power chip.