Features

 Green-Mode PWM Controller

 Low Startup Current: 5 μA

 Low Operating Current: 3 mA

 Programmable PWM Frequency

 Peak-Current-Mode Operation

 Leading-Edge Blanking

 Built-in Synchronized Slope Compensation

 Cycle-by-Cycle Current Limiting

 Constant Output Power Limit

 Gate Output Voltage Clamped at 15 V

 Small SSOT-6 Package

Applications

General-purpose switched-mode power supplies

(SMPS) and flyback power converters, such as:

 Battery chargers for cellular phones, cordless phones,

PDAs, digital cameras, and power tools

 Power adapters for ink jet printers, video game

consoles, and portable audio players

 Open-frame SMPS for TV/DVD standby and auxiliary

supplies, home appliances, and consumer electronics

 Replacements for linear transformers and RCC SMPS

 PC 5 V Standby Power

Description

This highly integrated PWM controller provides several enhancements to meet the low standby-power needs of low-power SMPS. To minimize standby power consumption, the proprietary Green Mode provides off-

time modulation to continuously decrease PWM frequency under light-load conditions. Green Mode

enables the power supply to meet even strict power conservation requirements.

The BiCMOS fabrication process enables reducing the startup current to 5 μA and the operating current to 3 mA. As a result, a large startup resistance can be used. Built-in synchronized slope compensation ensures the stability of peak-current-mode control. Proprietary internal compensation provides a constant output power limit over a universal AC input range (90 VAC to

264 VAC). Cycle-by-cycle current limiting ensures safe operation during short-circuits.

To protect the external power MOSFET from damage by supply over voltage, the SG6848X1 output driver is clamped at 15 V. The SG6848X1 controllers can be used to improve the performance and reduce the production cost of power supplies. The SG6848X1 can replace linear and RCC power supplies. It is available in DIP-8 and SSOT-6 packages.