Datasheet Summary
PWM Current- Mode Controller for Free- Running Quasi- Resonant Operation
The NCP1378 bines 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. An internal 8.0 ms timer prevents the free- run frequency to exceed 100 kHz (therefore below the 150 kHz CISPR- 22 EMI starting limit), while the skip adjustment capability lets the...