Time (500 µs/div)

Output

Ground

0 V

2

2

Total Error (%) =

Total Gain Error (%) + Total Offset Error (%)

22

INA180, INA2180

SBOS741A – APRIL 2017 – REVISED AUGUST 2017

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One method of calculating the total error is to add the gain error to the percentage contribution of the offset error.

However, in this case, the gain error and the offset error do not have an influence or correlation to each other. A

more statistically accurate method of calculating the total error is to use the RMS sum of the errors, as shown in

Equation 7.

(7)

After applying Equation 7, the total current sense error at maximum current is calculated to be 1.25%, and that is

less than the design example requirement of 1.5%.

The gain-of-200 device also has a bandwidth of 105 kHz that meets the small-signal bandwidth requirement of

80 kHz. If higher bandwidth is required, lower-gain devices can be used at the expense of either reduced output

9.2.3 Application Curve

An example output response of a unidirectional configuration is shown in Figure 42. The device output swing is

limited by ground; therefore, the output is biased to this zero output level. The output rises above ground for

positive differential input signals, but cannot fall below ground for negative differential input signals.

Figure 42. Output Response