The power supply chip is the power supply heart of all electronic equipment, controls the pulse power of electronic equipment, and is responsible for the power conversion, distribution, detection and other functions. Once the failure, resulting in electronic equipment stop working or even damage, this is a very critical equipment in electronic equipment.
Power supply chip is an indispensable component of electronic equipment. If the power chip is damaged in the circuit, the electronic device will stop working. So how should we detect it? Let's learn how to measure the power chip in the power supply circuit together with The Small edition of Jiafeng Core City.
1. Offline detection: measure the positive and negative resistance values between the pins of the IC chip to the ground, so as to compare with good IC chips and find out the fault point;
2. Online detection: The detection method of DC resistance is the same as that of offline detection. However, it should be noted that the power supply on the circuit board should be disconnected, and the internal voltage of the multimeter should not be greater than 6V. Pay attention to peripheral effects when measuring;
3. Ac working voltage test method: use a multimeter with DB file to measure the ac voltage approximation of the chip. If there is no DB file, a 0.1-0.5μF isolated DC capacity can be connected in series in the positive pen. This method is suitable for IC with low operating frequency. However, it is important to note that these signals are affected by different frequencies and waveforms, so the measured data is approximate.
4. Total current measurement method: Judge the quality of the chip by measuring the total current of the power supply chip. Since most chips are DC coupled, when an integrated circuit is damaged (such as a PN junction breakdown or circuit break), post saturation and circuit break can result, changing the total current. Therefore, measuring the total current can determine the quality of the chip. The current value can be calculated by measuring the voltage across the resistance of the circuit.
Before testing the power supply chip, we need to master the application of integrated circuit in the circuit. Internal structure principle. If necessary, analyze the internal power schematic diagram to better determine and prove whether the equipment is indeed damaged. Through the method, engineers can generally quickly judge the quality of the power supply chip.