ZHCSL81A May 2020 – June 2021 INA229-Q1
PRODUCTION DATA
Parametric values are calculated by multiplying the returned value by the LSB value. Table 8-4 below shows the returned values for this application example assuming the design requirements shown in Table 8-3.
PARAMETER | Returned Value | LSB Value | Calculated Value |
---|---|---|---|
Shunt voltage (V) | 311040d | 312.5 nV/LSB | 0.0972 V |
Current (A) | 314572d | 10 A/ 219 = 19.073486 µA/LSB | 6 A |
Bus voltage (V) | 245760d | 195.3125 µV/LSB | 48 V |
Power (W) | 4718604d | Current LSB x 3.2 = 61.035156 µW/LSB | 288 W |
Energy (J) | 1061683200d | Power LSB x 16 = 976.5625 µJ/LSB | 1036800 J |
Charge (C) | 1132462080d | Current LSB = 19.073486 µC/LSB | 21600 C |
Temperature (°C) | 3200d | 7.8125 m°C/LSB | 25°C |
Shunt Voltage, Current, Bus Voltage (positive only), Charge, and Temperature return values in two's complement format. In two's complement format a negative value in binary is represented by having a 1 in the most significant bit of the returned value. These values can be converted to decimal by first inverting all the bits and adding 1 to obtain the unsigned binary value. This value should then be converted to decimal with the negative sign applied. For example, assume a shunt voltage reading returns 1011 0100 0001 0000 0000. This is a negative value due to the MSB having a value of one. Inverting the bits and adding one results in 0100 1011 1111 0000 0000 (311040d) which from the shunt voltage example in Table 8-4 correlates to a voltage of 97.2 mV. Since the returned value was negative the measured shunt voltage value is -97.2 mV.