Datasheet

I I I II I I II I I II I I I
V
V V VV V V VV V V VV V V V
P P P P P P P P P P P P P P P P
Current Limit Detect Following
Every Shunt Voltage Conversion
Bus and Power Limit Detect
Following Every Bus Voltage Conversion
Power Average
Bus Voltage Average
Shunt Voltage Average
INA230
www.ti.com SBOS601 –FEBRUARY 2012
Although the INA230 can be read at any time, and the data from the last conversion remain available, the
Conversion Ready Flag bit (CVRF bit, Mask/Enable register) is provided to help coordinate single-shot or
triggered conversions. The CVRF bit is set after all conversions, averaging, and multiplication operations are
complete for a single cycle.
The CVRF bit clears under these conditions:
1. Writing to the Configuration register, except when configuring the MODE bits for power-down mode; or
2. Reading the Status register.
Power Calculation
The current and power are calculated after shunt voltage and bus voltage measurements, as shown in Figure 20.
The current is calculated after a shunt voltage measurement based on the value set in the Calibration register. If
there is no value loaded into the Calibration register, the current value stored is zero. Power is calculated
following the bus voltage measurement based on the previous current calculation and bus voltage measurement.
If there is no value loaded in the Calibration register, the power value stored is also zero. These calculations are
performed in the background and do not add to the overall conversion time. These current and power values are
considered intermediate results (unless the averaging is set to 1) and are stored in an internal accumulation
register, not the corresponding output registers. Following every measured sample, the newly-calculated values
for current and power are appended to this accumulation register until all of the samples have been measured
and averaged based on the number of averages set in the Configuration register.
Figure 20. Power Calculation Scheme
In addition to the current and power accumulating after every sample, the shunt and bus voltage measurements
are also collected. Once all of the samples have been measured and the corresponding current and power
calculations have been made, the accumulated average for each of these parameters is then loaded to the
corresponding output registers, where they can then be read.
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