SG6846A

SG6846A — Highly Integrated Green-Mode PWM Controller SG6846A Highly Integrated Green-Mode PWM Controller Features  Low Startup Current: 8µA  Low Operating Current: 3.7mA  Peak-Current Mode of Operation with Cycle-by- Cycle Current Limiting  PWM Frequency Continuously Decreasing with Burst Mode at Light Loads  VDD Over-Voltage Protection (OVP)  AC Input Brownout Protection with Hysteresis  Constant Output Power Limit (Full AC Input Range)  Internal Latch Circuit for OVP, OTP, and OCP  Two-level OCP Delay: 1600ms  Output Short-Circuited Delay Time: 100ms  Programmable PWM Frequency with Frequency Hopping  OCP Threshold is Half Peak Current Limit  Feedback Open-loop Protection with 1700ms Delay  Built-in Soft-Start Applications General-purpose switch-mode power supplies and flyback power converters, including:  Power Adapters  Open-frame SMPS  SMPS with Surge-current Output, such as for Printers, Scanners, Motor Drivers Description The SG6846A is especially designed for SMPS with surge-current output, incorporated with a two-level OCP function. Besides the cycle-by-cycle current limiting, if the switching current is higher than two thirds the peakcurrent threshold for 1700ms, over-current protection is activated such that the SG6846A is latched off. If the switching current is higher than two thirds of the peak-current threshold for 100ms, and the voltage on the VDD is still higher than VDD-OFF + 1V, the PWM pulses are latched off immediately once the VDD vo...