Description

The highly integrated PWM controller, SG6846B, provides several features to enhance the performance of fly-back converters. To minimize standby power consumption, a proprietary green-mode function provides off-time modulation to continuously decrease the switching frequency under light-load conditions. Under zero-load conditions, the power supply enters burst-mode. This completely shuts off PWM output.

Features

Low Startup Current: 8µA

Low Operating Current: 3.7mA

Peak-Current Mode 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 (BLSY, BLSZ)

Two-level OCP Delay with 200ms

Programmable PWM Frequency with Frequency Hopping

OCP Threshold is 2/3 Peak Current Limit

Soft Startup Time: 5ms

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