Diodes pulse width modulation controller effectively improves efficiency

     Diodes introduces the AP3125 series of pulse Width modulation (PWM) controllers designed to increase efficiency and eliminate no-load losses. The AP3125 current mode device is optimized for use with offline AC-DC converters in portable products, consumer electronics and home appliances.

     The new controller offers three operating modes to improve performance. In normal mode, the switching frequency of the device is 65kHz or 100kHz. At moderate loads, these controllers go into green mode and perform frequency reversals to roll back frequency and increase average efficiency. Under no-load or ultra-light load, the device operates in pulse mode to minimize standby power.

     The AP3125 controller comes in a SOT26 package with a switching frequency set as low as 20kHz to minimize audible noise. Both normal and green modes have frequency jitter function to effectively reduce electromagnetic interference.

     The new controller enhances internal slope compensation to help simplify feedback loop design and achieve more stable peak current control over a wide input voltage range and load. In addition, the internal linear compensation feature of the AP3125 series ensures that the output power limit is consistent throughout the linear voltage range.

     To improve system reliability, the new product integrates a range of protection features that are more complete than similar devices, including internal overtemperature protection and rapid overcurrent protection, as well as overvoltage and overload protection. The AP3125B and AP3125HB also integrate power failure and linear overvoltage protection, which can be easily configured with several resistance dividers.