SG6846G

A highly integrated PWM controller, SG6846G 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, which completely shuts off PWM output. 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 SG6846G 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, SG6846G shuts down immediately. SG6846G also integrates a 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 constant output 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 SG6846G 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 latches off the controller. The latch resets when V_DD supply is removed.

SG6846G is available in an 8-pin SOP package.