The SG348xG series of current mode PWM controllers combine high performance with green mode power saving. The SG348xG controllers are fully pin-to-pin compatible with bipolar UC384X devices, but they have improved features and functionality. SG384xG series controllers are compatible with BiCMOS process manufacturing process, enabling the use of low start-up current and operating current. This feature further improves power conversion efficiency. The minimum startup current has been reduced to 5uA, and the minimum operating current has been reduced to 5mA. Each SG384xG features a slew rate controlled high current totem pole output ideal for driving power MOSFETs while keeping EMI low. Typical current sensing has a propagation delay of 50ns, resulting in significantly more efficient constant supply protection. During normal operation, the SG384xG controller acts as a fixed frequency PWM controller. “The external RT and CT values ​​can be easily programmed by changing the PWM frequency. The SG384xG includes two green-mode functions that drastically reduce power usage and help the power supply comply with the latest international energy conservation guidelines. To cut power consumption under light load conditions, The green mode function of the controller will linearly reduce the PWM frequency in response to output load reduction. Under ultra light-load/zero-load conditions, the RT/CT checks that the PWM oscillator periodically shuts down and enters burst mode. This causes the IC's power supply The voltage starts to drop gradually. Just as the supply voltage drops below the UVLO threshold voltage, the PWM oscillator of the RT/CT spins back to prevent the supply voltage from falling below the UVLO voltage. The SG384xG controllers also feature over-voltage protection (OVP). This The PWM output will be turned off if the supply voltage exceeds 27 V. The SG384xG series are available in 8-pin DIP and SOP packages.