Description
The highly integrated SG6742HL/HR PWM controller 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 linearly decrease the switching frequency at light-load conditions. To avoid acoustic-noise problems, the minimum PWM frequency is set above 22KHz. This green-mode function enables the power supply to meet international power conservation requirements. With the internal high-voltage startup  circuitry, the power loss due to bleeding resistors is eliminated. To further reduce power consumption, SG6742HL/HR is manufactured using the BiCMOS process, which allows an operating current of 2.7mA.

FEATUREs
ƒ  High-Voltage Startup
ƒ  Low Operating Current: 2.7mA
ƒ  Linearly Decreasing PWM Frequency to 22KHz
ƒ  Frequency Hopping to Reduce EMI Emission
ƒ  Fixed PWM Frequency: 100KHz
ƒ  Peak-Current-Mode Control
ƒ  Cycle-by-Cycle Current Limiting
ƒ  Leading-Edge Blanking (LEB)
ƒ  Synchronized Slope Compensation
ƒ  Internal Open-Loop Protection
ƒ  GATE Output Maximum Voltage Clamp: 18V
ƒ  VDDUnder-Voltage Lockout (UVLO)
ƒ  VDDOver-Voltage Protection (OVP)
ƒ  Programmable Over-Temperature Protection (OTP)
ƒ  Internal Latch Circuit (OVP, OTP)
ƒ  Internal-Sense, Short-Circuit Protection
ƒ  Built-in 6ms Soft-Start Function
ƒ  Constant Power Limit (Full AC Input Range)
ƒ  Internal OTP Sensor with Hysteresis

APPLICATIONs
General-purpose switch-mode power supplies and flyback power converters, including:
ƒ  Power Adapters
ƒ  Open-Frame SMPS