U3848

The UTC U3848/A/B/C is designed to provide several special enhancements to satisfy the needs: Power-Saving mode for low standby power, Over Current Protection (OCP), Over Voltage Protection (OVP), Over Load Protection (OLP), Over Temperature Protection (OTP) etc protection features. UTC U3848/A/B/C will be shutdown when either protection arise and can auto-restart. UTC U3848/A/B/C's frequency may be defined by user through resistor RT to external ground. UVLO featuring typical start-up current 20µA, and VCC(ON) 12.6V, VCC(OFF) 8.1 . Lower typical operation current Icc 3.7mA at inactive output.

The output stage, UTC U3848/A/B/C is suitable for driving N-Channel MOSFETs, can operate to duty cycles approach 70%. The U3848/A/B/C are fully pin-to-pin compatible with UC3842. But pin RT only connected a resistor to ground to decide switch frequency, and pin FB with an 4kΩ pull up resistor to internal reference voltage. The U3848/A/B/C also have soft-start function avoiding overshoot, and controlled driver output rise edge time tR for low EMI.