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INA4180-4181EVM Schematic and PCB Layout
7 SBOU189 – November 2017
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INA4180-INA4181 Evaluation Module User's Guide
The INA4181A1-A4 are able to measure bidirectional currents. The ability to measure this current flowing
in both directions is enabled by applying a voltage to the REF1 pin. The voltage applied to REF1 sets the
output state that corresponds to the zero-input level state. The output then responds by increasing above
REF1 for positive differential signals (relative to the IN–1 pin) and responds by decreasing below REF1 for
negative differential signals. This reference voltage applied to the REF1 pin can be set anywhere from 0 V
to VS. For bidirectional applications, REF1 is typically set at mid-scale for equal signal range in both
current directions. In some cases, however, REF1 is set at a voltage other than mid-scale when it is
unnecessary that the bidirectional current and corresponding output signal be symmetrical.
5 INA4180-4181EVM Schematic and PCB Layout
NOTE: Board layouts are not to scale. These figures are intended to show how the board is laid out.
The figures are not intended to be used for manufacturing INA4180-181EVM PCBs.
5.1 Schematics
Figure 1 shows the schematic for the INA4180Ax section of the INA4180-4181EVM PCB, and Figure 2
shows the schematic for the INA4181Ax section of the INA4180-4181EVM PCB.
Figure 1. INA4180Ax Schematic