You can refer to below attached:
For shunt resistor current in registers MEASE_ISENSEx (signed 19-bit value):
I = ((MEAS_ISENSE1[14..0]<< 4 + MEAS_ISENSE2[3..0])) * V2RES)/Rshunt (in μV)
where Rshunt is the current shunt resistor value in Ohm.
Pseudo-code:
ReadRegister(MEAS_ISENSE1)
ReadRegister(MEAS_ISENSE2)
// combine upper 15 bits with lower 4 bits → 19 bit signed
value
rawCurrent = ((MEAS_ISENSE1&0x7FFF)<<4) |
(MEAS_ISENSE2&0x000F)<<0)
// sign extend s19 to s32
if(rawCurrent & BIT(18)) {
rawCurrent |= 0xFFF80000;
}else{
// nothing to do
}
// calculate/scale current in amps
current = rawCurrent * V2RES / Rshunt
Example: with V2RES = 0.6 μV/LSB, MEAS_ISENSE1[15..0] = 0x8257,
MEAS_ISENSE2[15..0] = 0x8200 A and Rshunt = 100 μΩ:
then MEAS_ISENSE1 [14..0] << 4 = 0x0257 << 4 = 0x2570 = 9584
then I = (9584 + 0) * 0.6 μv/100 μΩ = 57504000 μA = 57.504 A
