Tips for improving the safety and reliability of power adapter design

In our daily life, we sometimes encounter some minor problems with the power adapter. Commonly used mobile phone chargers, PC power supplies, and power adapters of some small appliances are damaged. So how can we design safe, reliable and durable products?

1. Voltage stress

The power supply voltage stress is an important indicator to ensure the reliability of the power supply. There are many devices in the power supply that have a specified maximum withstand voltage, such as the reverse withstand voltage of the diode, the maximum voltage of the IC, and the maximum withstand voltage of the input and output capacitors. Therefore, we must consider the maximum voltage that the device must withstand when designing. Then select the appropriate device according to the voltage, and finally perform actual tests to verify it.

2. Current stress

The power supply current stress is often closely related to the thermal stress. For example, the diode current is 5A, but it is the limit parameter under the premise of satisfying the thermal stress derating. Therefore, when we select a device, we must meet the current stress and thermal stress of the device at the same time; on the premise of meeting the thermal stress of the device, selecting a device with a suitable rated current value can ensure the reliability of the power supply.

3. Protection circuit

The protection circuit specifically includes input undervoltage protection, input overvoltage protection, output overcurrent protection, output short circuit protection, and output overvoltage protection. In order to avoid abnormal operation of the power supply when the input voltage is too low, the power supply needs to add input undervoltage protection; to avoid the input voltage is too high, and the voltage stress during the period exceeds the standard, the power supply needs to add input overvoltage protection; to avoid output overcurrent and Short-circuit causes the device to overheat, magnetic saturation and other phenomena. The power supply needs to add over-current protection and short-circuit protection; in order to avoid the power supply's output voltage from being too high and causing damage to the power load end, the power supply needs to add output over-voltage protection.

And EMC, safety regulations and overheating protection are all key factors affecting the reliability of the power supply. Shenzhen Senshuqiang's 20 years of research and exploration experience and a strong R&D team have helped us produce high-quality and stable power products of various specifications.