NCP1606 Cost Effective Power Factor Controller The NCP1606 is an active power factor controller specifically designed for use as a preconverter in electronic ballasts, acdc adapters and other medium power off line converters (typically up to NCP1606 V CC Shutdown V OUT nPOK V CC UVP UVLO + V ESD + DD R C OUT1 BULK 300 V DDGD mV (Enable EA) V Reg DD FB Dynamic OVP E/A + I >I sink ovp ESD R OUT2 Measure uV D DD BOOST I EAsink Fault 2.5 V V DD Static OVP V EAL Enable Static OVP is triggered Clamp C COMP V CONTROL when clamp is activated. Control ESD V EAH Clamp L AC IN nPOK BOOST V DD PWM 270 A Add V Ct EAL + Offset ESD Ct Q S DRV R Q OCP + LEB CS ESD V CC V CS(limit) UVLO R SENSE Demag DRV + V S Q DD S Q 2.1 V R Q V CL(NEG) R Q + V ddGD Active Clamp Off Timer 1.6 V uV DD ZCD S Q Reset + R Shutdown ZCD R GND Q 200 mV V CL(POS) S Q POK uV DD Clamp nPOK R Q *All SR Latches are Reset Dominant *All values shown are typical only. Refer to the Electrical Characteristics for complete specifications. Figure 2. Block Diagram