The LMZM23600 devices features two current limits inside the IC. A coarse high side or peak current limit is provided to protect against faults. The high-side current limit limits the duration of the on-period of the high-side power MOSFET during a given clock cycle. A precision cycle-by-cycle valley current limit prevents excessive average output current. A new switching cycle is not initiated until the inductor current drops below the valley current limit.

Figure 8-1 Current Limit Operation During Output Short Circuit

Figure 8-1 shows the response of the LMZM23600 device to a short circuit on the output: The peak current limit prevents excessive peak current while the valley current limit prevents excessive average inductor current. After a small number of cycles, hiccup mode is activated.