SG6742中文資料仙童半導(dǎo)體數(shù)據(jù)手冊(cè)PDF規(guī)格書

DESCRIPTION

The highly integrated SG6742 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 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 start-up circuitry, the power loss due

to bleeding resistors is eliminated. To further reduce power consumption, SG6742 is manufactured using the BiCMOS process, which allows an operating current of 4mA.

FEATURES

? High-voltage start-up

? Low operating current (4mA)

? Linearly decreasing PWM frequency to 22KHz

? Frequency jittering to reduce EMI emission

? Fixed PWM frequency (65KHz)

? Peak-current-mode control

? Cycle-by-cycle current limiting

? Leading-edge blanking

? Synchronized slope compensation

? Internal open-loop protection

? GATE output maximum voltage clamp (18V)

? VDDunder-voltage lockout (UVLO)

? VDDover voltage protection (OVP)

? Programmable over-temperature protection (RT)

? Internal latch circuit (OVP, RT)

? Constant power limit (full AC input range)

? Internal OTP sensor with hysteresis

APPLICATIONS

General-purpose switch-mode power supplies and flyback power converters, including:

? Power Adapters

? Open-Frame SMPS