Part Number: 1207A
Function: PWM Current-Mode Controller for Free Running Quasi-Resonant Operation
Package: SOIC-8 Pin Type
Manufacturer: ON Semiconductor
Images:
Description
The NCP1207A, 1207A combines a true current mode modulator and a demagnetization detector to ensure full borderline/critical Conduction Mode in any load/line conditions and minimum drain voltage switching (Quasi-Resonant operation). Due to its inherent skip cycle capability, the controller enters burst mode as soon as the power demand falls below a predetermined level. As this happens at low peak current, no audible noise can be heard. For the NCP1207A, an internal 8.0 micro s timer prevents the free-run frequency to exceed 125 kHz (therefore below the 150 kHz CISPR-22 EMI starting limit), while the skip adjustment capability lets the user select the frequency at which the burst foldback takes place. For the NCP1207B, the internal timer duration is reduced to 4.5 micro s to allow operation at higher frequencies (up to 200 kHz).
Features
1. Free-Running Borderline/Critical Mode Quasi-Resonant Operation
2. Current-Mode with Adjustable Skip-Cycle capability
3. Auto-Recovery Over Current Protection
4. 500 mA Peak Current Source/Sink Capability
5. Internal 1.0 ms SoftStart
6. Internal 8.0 µs Minimum TOFF
7. Latched Over Voltage Protection
8. Adjustable skip level
Pinout:
Applications:
1. Auxiliary power supplies
2. AC/DC adapters for notebook
3. Offline battery chargers
4. Consumer electronics (DVD player, set-top box, TV)
Other data sheets are available within the file: NCP1207A, NCP1207B, 1207B
1207A Datasheet PDF
