8.3.5.1.1 Output Current Limit

The buck regulators have programmable output peak current limits. The limits are individually programmed for all buck regulators with BUCKx_CTRL2.ILIMx[2:0] bits. The current limit settings of master and slave regulators used for the same output voltage rail must be identical. If the load current is increased so that the current limit is triggered, the regulator continues to regulate to the limit current level (current peak regulation). The voltage may decrease if the load current is higher than limit current. If the current regulation continues for 20 µs, the LP8758 device sets the INT_BUCKx.BUCKx_ILIM_INT bit and pulls the nINT pin low. The host processor can read BUCKx_STAT.BUCKx_ILIM_STAT bits to see if the regulator is still in peak current regulation mode.

If the load is so high that the output voltage decreases below a 350-mV level, the LP8758 device disables the regulator and sets the INT_BUCK_0_1.BUCK0_SC_INT bit. In addition the BUCK_0_1_STAT.BUCK0_STAT bit is set to 0. The interrupt is cleared when the host processor writes 1 to INT_BUCK_0_1.BUCK0_SC_INT bit. The overload situation is shown in Figure 13.

Figure 13. Overload Situation