SLVSDV8 July 2017 TPS54424
The device implements current mode control which uses the COMP pin voltage to control the turnoff of the high-side MOSFET and the turnon of the low-side MOSFET on a cycle-by-cycle basis. Each cycle the switch current and the current reference generated by the COMP pin voltage are compared, when the peak switch current intersects the current reference the high-side switch is turned off. The maximum peak switch current through the high-side MOSFET for overcurrent protection is done by limiting the current reference internally. If the peak current required to regulate the output is greater than the internal limit, the output voltage is pulled low and the error amplifier responds by driving the COMP pin high. The maximum COMP voltage is then clamped by an internal COMP clamp circuit. If the COMP voltage is clamped high for more than the hiccup wait time of 512 switching cycles, the device will shut down itself and restart after the hiccup time of 16384 cycles.