Reliability Of Power Adapter Products

improve the reliability of power adapter design

In our daily life we sometimes encounter power adapters with some minor problems, such as cell phone chargers, PC power supplies and some small appliances with damaged power adapters. So how can we design a safe, reliable and more durable products? Today Eahunt shares its experience with you.

1, voltage stress

Power supply voltage stress is an important indicator to ensure the reliability of the power supply. There are many devices in the power supply have provisions for the maximum withstand voltage value, such as: field effect tube Vds and Vgs, diode reverse withstand voltage, IC's maximum VCC voltage as well as the input and output capacitors of the maximum withstand voltage. So when we design, we must take into account the maximum voltage that the device has to withstand. Then according to the voltage to select the appropriate device, and finally the actual test to verify. But in the test we must test the power supply voltage stress of all operating conditions to ensure that the worst operating conditions can also leave a safety margin of about 10%.

2、Current Stress

Power supply current stress is often closely related to thermal stress, such as diode SK54 maximum average current of 5A, but it is in the premise of meeting the thermal stress derating limit parameters. So when we choose the device must also meet the device current stress and thermal stress; under the premise of meeting the thermal stress of the device, select the appropriate rated current value of the device to ensure the reliability of the power supply requirements.

3. Protection circuit

Protection circuits include input under-voltage protection, input over-voltage protection, output over-current protection, output short-circuit protection and output over-voltage protection. In order to avoid the phenomenon of abnormal operation of the power supply when the input voltage is too low, the power supply needs to add input undervoltage protection; in order to avoid the input voltage is too high, so that the voltage stress during the period of exceeding the standard, the power supply needs to add input overvoltage protection; in order to avoid the output overcurrent and short-circuit, thus leading to device overheating, magnetic saturation and other phenomena, the power supply needs to add overcurrent protection and short-circuit protection; in order to avoid the power supply to output voltage is too high, resulting in damage to the power supply load terminal, the power supply needs to add output overvoltage protection. In order to avoid high output voltage causing damage to the load side of the power supply, the power supply needs to add output over-voltage protection.

There are many factors affecting the reliability of power adapters, such as EMC, safety regulations and thermal protection are key factors affecting the reliability of power supplies. Designing a power supply may not be too difficult, but to design a stable and reliable power supply will never be too easy. Fortunately, Eahunt has experience and a strong R & D team to help us produce high quality, stable power supply products.