COMP is the output of the error amplifier and the input of the PWM comparator. Unlike earlier-generation devices, the error amplifier in the UCC2813-x-Q1 device family is a true low-output-impedance 2-MHz operational amplifier. As such, the COMP terminal both sources and sinks current. However, the error amplifier is internally current limited, so zero duty cycle may be commanded by externally forcing COMP to GND.
The UCC2813-x-Q1 device family features built-in full cycle soft start at power up and after fault recovery, and no external components are necessary. Soft start is implemented as a rising clamp on the COMP voltage, increasing from 0 V to 5 V in 4 ms.