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●System General Corp.
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●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 UVLO lower limit. This green-mode function enables power supplies to easily meet international power conservation requirements.
●FEATURES
●■ Two-level OCP with 96mS delay time
●■ Peak-current-mode operation with cycle-by-cycle current limiting
●■ PWM frequency continuously decreasing w/ burst mode at light loads
●■ Low start-up current (8uA)
●■ Low operating current (3.7mA)
●■ VDD over-voltage protection (OVP)
●■ AC input brownout protection with hysteresis
●■ Programmable over-temperature protection (OTP)
●■ Constant power limit over universal AC input range
●■ Internal latch circuit for OTP, OVP, OCP
●■ Very few external components
●APPLICATIONS
●General-purpose switch mode power supplies and flyback power converters, including:
●■ Power adapters
●■ Open-frame SMPS
●■ Specifically fit for SMPS with surge-current output, such as for printers, scanners, motor drivers, etc.
