AD8206

Data Sheet

Rev. B | Page 10 of 16

OUTPUT OFFSET ADJUSTMENT

The output of the AD8206 can be adjusted for unidirectional or

bidirectional operation.

UNIDIRECTIONAL OPERATION

Unidirectional operation allows the AD8206 to measure

currents through a resistive shunt in one direction. The basic

modes for unidirectional operation are ground referenced

output mode and V+ referenced output mode.

For unidirectional operation, the output can be set at the

negative rail (near ground) or at the positive rail (near V+)

when the differential input is 0 V. The output moves to the

opposite rail when a correct polarity differential input voltage is

applied. In this case, full scale is approximately 250 mV. The

required polarity of the differential input depends on the output

voltage setting. If the output is set at the positive rail, the input

polarity needs to be negative to move the output down. If the

output is set at ground, the polarity is positive to move the

output up.

GROUND REFERENCED OUTPUT

When using the AD8206 in this mode, both referenced inputs are

tied to ground, which causes the output to sit at the negative rail

when there are zero differential volts at the input (see Figure 17).

AD8206

+IN

–IN

NC

NC = NO CONNECT

GND

V+

OUT

Figure 17. Ground Referenced Output

Table 4. V+ = 5 V

0 V

0.08 V

250 mV

4.7 V

V+ REFERENCED OUTPUT

This mode is set when both reference pins are tied to the

positive supply. It is typically used when the diagnostic scheme

requires detection of the amplifier and the wiring before power

is applied to the load (see Figure 18).

AD8206

+IN

–IN

NC

NC = NO CONNECT

GND

V+

OUT

Figure 18. V+ Referenced Output

Table 5. V+ = 5 V

0 V

4.7 V

−250 mV

0.08 V

BIDIRECTIONAL OPERATION

Bidirectional operation allows the AD8206 to measure currents

through a resistive shunt in two directions.

In this case, the output is set anywhere within the output range.

Typically, it is set at half-scale for equal range in both directions.

In some cases, however, it is set at a voltage other than half-scale

when the bidirectional current is nonsymmetrical.

+100 mV

4.5 V

−100 mV

0.5 V

Adjusting the output is accomplished by applying voltage(s) to

the referenced inputs.

internal offset node. There is no operational difference between

the pins.