SBOS547A June 2011 – August 2015 INA226
PRODUCTION DATA.
NOTE
Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Validate and test the design implementation to confirm system functionality.
The INA226 is a current shunt and power monitor with an I2C™ compatible interface. The device monitors both a shunt voltage drop and bus supply voltage. Programmable calibration value, conversion times, and averaging, combined with an internal multiplier, enable direct readouts of current in amperes and power in watts.
INA226 measures the voltage developed across a current-sensing resistor (RSHUNT) when current passes through it. The device also measures the bus supply voltage and can calculate power when calibrated. It comes with alert capability where the alert pin can be programmed to respond to a user-defined event or to a conversion ready notification. This design illustrates the ability of the alert pin to respond to a set threshold.
The Alert pin can be configured to respond to one of the five alert functions described in the Alert Pin section. The alert pin must to be pulled up to the VVS pin voltage via the pull-up resistors. The configuration register is set based on the required conversion time and averaging. The Mask/Enable Register is set to identify the required alert function and the Alert Limit Register is set to the limit value used for comparison.
Figure 28 shows the Alert pin response to a shunt voltage over-limit of 80 mV for a conversion time (tCT) of 1.1 ms and averaging set to 1. Figure 29 shows the response for the same limit but with the conversion time reduced to 140 µs.
BIT # | D15 | D14 | D13 | D12 | D11 | D10 | D9 | D8 | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
BIT NAME |
RST | — | — | — | AVG2 | AVG1 | AVG0 | VBUSCT2 | VBUSCT1 | VBUSCT0 | VSHCT2 | VSHCT1 | VSHCT0 | MODE3 | MODE2 | MODE1 |
POR VALUE | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 0 | 1 | 0 | 1 |
BIT # | D15 | D14 | D13 | D12 | D11 | D10 | D9 | D8 | D7 | D6 | D5 | D4 | D3 | D2 | D1 | D0 |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
BIT NAME |
RST | — | — | — | AVG2 | AVG1 | AVG0 | VBUSCT2 | VBUSCT1 | VBUSCT0 | VSHCT2 | VSHCT1 | VSHCT0 | MODE3 | MODE2 | MODE1 |
POR VALUE | 0 | 1 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 1 | 0 | 1 |