8.3.1.5 Buck Converter Load-Current Measurement

Buck load current can be monitored via I²C registers. The monitored buck converter is selected with the LOAD_CURRENT_BUCK_SELECT[1:0] bits in SEL_I_LOAD register. A write to this selection register starts a current measurement sequence. The regulator is forced to PWM mode during the measurement. The measurement sequence is 50 µs long, maximum. The LP8756x-Q1 device can be configured to give out an interrupt (I_LOAD_READY bit in INT_TOP1 register) after the load current measurement sequence is finished. Load current measurement interrupt can be masked with I_LOAD_READY_MASK bit (TOP_MASK1 register). The measurement result can be read from registers I_LOAD_1 and I_LOAD_2. Register I_LOAD_1 bits BUCK_LOAD_CURRENT[7:0] give out the LSB bits and register I_LOAD_2 bits BUCK_LOAD_CURRENT[9:8] the MSB bits. The measurement result BUCK_LOAD_CURRENT[9:0] LSB is 20 mA, and maximum value of the measurement corresponds to 20.46 A. If the selected buck regulator is a master phase, the measured current is the total value of the master and slave phases. If the selected buck regulator is single-phase or slave phase, the measured current is the output current of the selected phase.