This document describes the operation and features of the FAN7601. This device is a BCDMOS programmable frequency current mode PWM controller which is designed for off-line adapter applications and auxiliary power supplies. To reduce power loss at light and no load, the FAN7601 operates in burst mode and it includes a start-up switch to reduce the losses in the start-up circuit. Because of the internal start-up switch and burst mode operation, it is possible to supply an output power of 0.5W with under 1W input power when the input line voltage is 265V. On no load condition, input power is under 0.3W. The FAN7601 offers a latch protection pin for the protection of the system e.g. over voltage protection and/or thermal shutdown. The internal over voltage protection function shuts down the IC operation when the supply voltage reaches 19V. In addition, a soft start function is provided, and the soft start time can be varied.
The document provides an introduction to the Fairchild FAN7601, identifying it as a BCDMOS programmable frequency current mode PWM controller designed specifically for off-line adapter applications and auxiliary power supplies. Key features highlighted include burst mode operation to reduce power loss at light or no load conditions, an internal start-up switch, and latch protection for over-voltage and thermal shutdown.
| Reference output voltage (Vref) | 5V |
|---|---|
| Soft start current source | 12uA |
| Output drive peak current | up to 100mA |
| Typical rise time (with 1.0nF load) | 45ns |
| Typical fall time (with 1.0nF load) | 35ns |
| Burst mode entry threshold (CS/FB offset) | > 0.97V |
| Burst mode exit threshold (CS/FB offset) | < 0.9V |
The device is designed for off-line adapter applications and auxiliary power supplies.
It operates in burst mode to reduce power loss.
It provides latch protection for over-voltage protection and/or thermal shutdown.