SLYS023A December 2020 – May 2022 INA229
The INA229 device supports two input ranges for the shunt voltage measurement. The supported full scale differential input across the IN+ and IN– pins can be either ±163.84 mV or ±40.96 mV depending on the ADCRANGE bit in CONFIG register. The range for the bus voltage measurement is from 0 V to 85 V. The internal die temperature sensor range extends from –256 °C to +256 °C but is limited by the package to –40 °C to 125 °C.
Table 8-1 provides a description of full scale voltage on shunt, bus, and temperature measurements, along with their associated step size.
|PARAMETER||FULL SCALE VALUE||RESOLUTION|
|Shunt voltage||±163.84 mV (ADCRANGE = 0)||312.5 nV/LSB|
|±40.96 mV (ADCRANGE = 1)||78.125 nV/LSB|
|Bus voltage||0 V to 85 V||195.3125 µV/LSB|
|Temperature||–40 °C to +125 °C||7.8125 m°C/LSB|
The device shunt voltage measurements, bus voltage, and temperature measurements can be read through the VSHUNT, VBUS, and DIETEMP registers, respectively. The digital output in VSHUNT and VBUS registers is 20-bits. The shunt voltage measurement can be positive or negative due to bidirectional currents in the system; therefore the data value in VSHUNT can be positive or negative. The VBUS data value is always positive. The output data can be directly converted into voltage by multiplying the digital value by its respective resolution size. The digital output in the DIETEMP register is 16-bit and can be directly converted to °C by multiplying by the above resolution size. This output value can also be positive or negative.
Furthermore, the device provides the flexibility to report calculated current in Amperes, power in Watts, charge in Coulombs and energy in Joules as described in Section 8.1.2.