
Fairchild Semiconductor
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 peak
current threshold for 1700ms, over-current protection is activated such that the SG6846A is latched off.
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
VDDOver-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