When the CSP-CSN voltage exceeds the 60-mV cycle-by-cycle current limit threshold (V_CLTH), the current limit comparator immediately terminates the LO output. The device provides an constant peak current limit whose peak inductor current limit is constant over the input and output voltage. For the case where the inductor current can overshoot, such as inductor saturation, the current limit comparator skips pulses until the current has decayed below the current limit threshold.

Figure 9-16 Current Limit Comparator

Cycle-by-cycle peak current limit is calculated as follows:

Equation 11.

Figure 9-17 Current Limit Comparator Input

Boost converters have a natural pass-through path from the supply to the load through the high-side MOSFET body diode. Due to this path, boost converters cannot provide the peak current limit protection when the output voltage is close to or less than the input supply voltage, especially the peak current limit protection that does not work during the minimum on time (t_ON-MIN).