[System General Corporation]
DESCRIPTION
This high-integrated PWM controller provides several special enhancements to satisfy the needs for low power standby and protection features. In standby mode, PWM frequency reduction is used to lower the power consumption and support a stable output voltage. Due to Bi-CMOS process, the SG6840 reduces start up and operation current to achieve a higher efficiency power conversion. Start-up current has been reduced to 30uA typical and operating current has been shrunk to 3mA. The SG6840 is a fixed frequency PWM controller in normal operation; its patented green-mode function will decrease the PWM frequency in response to the decrease of the load.
FEATURES OVERVIEW
âGreen-mode PWM to support “Blue Angle”Norm
âLow start up current 30uA
âLow operation current 3mA
âLeading-edge blanking
âBuilt-in synchronized slope compensation
âTotem pole output includes soft driving
âConstant output power
âCurrent mode operation
âCycle-by-cycle current limiting
âUnder voltage lockout (UVLO)
âShort circuit protection
âProgrammable over-temperature protection
âFew external components & low cost solution
APPLICATIONS
General-purpose switching mode power supplies and flyback power converters, and
âPower Adapter
âOpen-frame SMPS
âBattery Charger Adapter
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