SNVSAT4A September 2017 – June 2021 LP873220-Q1
The buck load current can be monitored through I2C registers. The monitored buck converter is selected with the LOAD_CURRENT_BUCK_SELECT bit in the SEL_I_LOAD register. A write to this selection register starts a current measurement sequence. The regulator is automatically forced to the PWM mode for the measurement period. The measurement sequence is 50 µs long, maximum.
The LP873220-Q1 device can be configured to give out an interrupt (the I_MEAS_INT bit in the INT_TOP_1 register) after the load current measurement sequence is finished. The load current measurement interrupt can be masked with the I_MEAS_MASK bit (TOP_MASK_1 register). The measurement result can be read from the registers I_LOAD_1 and I_LOAD_2. The register I_LOAD_1 bits BUCK_LOAD_CURRENT[7:0] gives out the LSB bits, and the register I_LOAD_2 bit BUCK_LOAD_CURRENT gives out the MSB bit. The measurement result BUCK_LOAD_CURRENT[8:0] LSB is 20 mA, and the maximum code value of the measurement corresponds to 10.22 A.