Advanced pre-biased PWM control IC – What is the UCC28250 pin function?

(2) VREF (20/7): This terminal output is 3.3V.

(3) EN (18/5): The following conditions must be met before the controller is started: 1) The voltage at the VDD terminal rises above the threshold of 4.3V.2) The 3.3V reference is above 2.4V.3) The junction temperature is lower than l30.4) RT (15/2): The UCC28250 oscillator frequency setting is connected between the RT terminal and GND with the same external Resistors. The selection of the switching frequency is based on the compromise between the component size and the frequency.Each output (OUTA, OUTB, SRA, SRB) is half the oscillation frequency.The value of Ps is determined by Figure l0.7.

(7) RAMP/CS (16/3): The UCC28250 can be controlled either by voltage or current.(8) REF/EA (1/8): is the non-inverting input of the UCC28250 internal error amplifier.

(9) FB/EA one (2/9): FB/EA one is the inverting input of the UCC28250 internal error amplifier.

12) SS (13/20): The soft start circuit gradually increases the output voltage of the converter until it reaches the steady state, reducing the surge of starting stress and current.

(13) ILIM (17/4): Cycle-by-cycle current limiting, it is recommended to use the ILIM terminal (whether current or voltage).The VP/OTP terminal provides multiple fault protection functions. If the 0VP/OTP terminal voltage exceeds 0.7v, a fault shutdown occurs. All outputs stop the switch and stop at this state, and the SS terminal level is pulled to GND.

16) OUTA and OUTB: This is the primary side two switch control signals with 0.2A peak current capability.