SG6846C

The highly integrated PWM controller, SG6846C 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 decreasethe switching frequency under light-load conditions. Under zero-load conditions, the power supply enters burst-mode, which 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 meet international power conservation requirements.

The SG6846C is designed for SMPS with surge-current output, incorporated with a two-level OCP function.Besides the cycle-by-cycle current limiting, if the switching current is higher than OCP threshold and lasts for 110ms,SG6846C shuts down immediately. SG6846C also integrates frequency-hopping function internally,which helps reduce EMI emission of a power supply with minimum line filters. The built-in synchronized slope compensation provides proprietary internal compensation for constantoutput power limit over a universal AC input range. The gate output is clamped at 18V to protect the external MOSFET from over-voltage damage.

Other protection functions of SG6846C include AC input brownout protection with hysteresis and V_DD over-voltage protection.For over-temperature protection, an external NTC thermistor can be applied to sense the ambient temperature.When OCP, V_DD OVP, or OTP are activated, an internal latch circuit is used to latch-off the controller.The latch resets when the V_DD supply is removed.

SG6846C is available in 8-pin SOP and DIP packages.