SG6846

SG6846 — Highly Integrated Green-Mode PWM Controller SG6846 Highly Integrated Green-Mode PWM Controller Features ƒ Low Startup Current: 8µA ƒ Low Operating Current: 3.7mA ƒ Peak-Current Mode of Operation with Cycle-by- Cycle Current Limiting ƒ PWM Frequency Continuously Decreasing with Burst Mode at Light Loads ƒ VDD Over-Voltage Protection (OVP) ƒ AC Input Brownout Protection with Hysteresis ƒ Constant Output-Power Limit (Full AC Input Range) ƒ Internal Latch Circuit for OVP, OTP, and OCP ƒ Two-level Over-Current Protection (OCP) with 96ms Delay Time ƒ Very Few External Components ƒ Programmable Over-Temperature Protection (OTP) Applications General-purpose switch-mode power supplies and flyback power converters, including: ƒ Power Adapters ƒ Open-Frame SMPS ƒ SMPS with Surge-Current Output, such as for Printers, Scanners, Motor Drivers Description The highly integrated SG6846 series of PWM controllers provides several features to enhance the performance of flyback 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. The output restarts just before the supply voltage drops below the under-voltage lockout (UVLO) lower limit. This green-mode function enables power supplies to meet international power conservation requirements easily. The...