The FL7701 is a PWM peak current controller for a buck converter topology operating in Continuous Conduction Mode (CCM) with an intelligent PFC function using a digital control algorithm.
This document is an application note for the Fairchild Semiconductor FL7701, a PWM peak current controller for buck converter topologies with an intelligent Power Factor Correction (PFC) function. The IC operates in Continuous Conduction Mode (CCM) and features an internal self-biasing circuit and a digital control algorithm to adjust to AC or DC input conditions automatically.
| Topology | Buck converter |
|---|---|
| Operation Mode | Continuous Conduction Mode (CCM) |
| Input Voltage (Max.) | 305 Vac or 400 Vpc |
| Fixed Output Frequency (RT open) | 45kHz |
| Maximum Duty Cycle | 50% |
| Internal Duty Ratio Range | 2% to 50% |
| Over-Current Protection Threshold | 2.5V |
No, the FL7701 has an intelligent internal PFC function that does not require additional detection pins or other components.
Yes, it can operate from DC and AC input voltages without limitation.
The IC cannot start because it has a high-voltage power supply circuit that self-biases using a high-voltage process device.