ADR130

Rev. 0 | Page 14 of 16

NEGATIVE PRECISION REFERENCE WITHOUT

PRECISION RESISTORS

A negative reference is easily generated by adding an op amp,

ground and, therefore, the negative reference can be taken

directly from the output of the op amp. The op amp must be

dual-supply, low offset, and rail-to-rail if the negative supply

voltage is close to the reference output.

1

2

3

6

5

4

NC

GND

SET

NC

U2

ADR130

0.1µF

V+

V–

A1

OP291

1kΩ

PRECISION CURRENT SOURCE

In low power applications, the need can arise for a precision

current source that can operate on low supply voltages. The

ADR130 can be configured as a precision current source (see

Figure 37). The circuit configuration shown is a floating current

source with a grounded load. The reference output voltage is

load. With this configuration, circuit precision is maintained for

load currents ranging from the reference supply current,

typically 85 μA, to approximately 4 mA.

1

2

3

6

5

4

NC

GND

SET

NC

ADR130

P1

Figure 37. ADR130 as a Precision Current Source