ADR381ARTZ-REEL7(RevC) View Datasheet(PDF) - Analog Devices

Part Name

Description

Manufacturer

ADR381ARTZ-REEL7
(Rev.:RevC)

Precision Low Drift 2.048 V/2.500 V SOT-23 Voltage Reference

Analog Devices 

PRECISION HIGH CURRENT VOLTAGE SOURCE

In some cases, the user may want higher output current delivered

to a load and still achieve better than 0.5% accuracy from the

ADR380/ADR381. The accuracy for a reference is normally

specified on the data sheet with no load. However, the output

voltage changes with load current.

The circuit in Figure 30 provides high current without compromis-

ing the accuracy of the ADR380/ADR381. By op amp action,

VOUT follows VREF with very low drop in R1. To maintain circuit

equilibrium, the op amp also drives the N-Channel MOSFET

Q1 into saturation to maintain the current needed at different

loads. R2 is optional to prevent oscillation at Q1. In such an

approach, hundreds of milliamps of load current can be achieved,

and the current is limited by the thermal limitation of Q1. VIN =

VOUT + 300 mV.

ADR380/ADR381

VIN

R1

100kΩ

8V TO 15V

C1

0.001µF

Q1

1

VIN

2

VOUT

+V

A1

–V

AD820

2N7002

R2

100Ω

U1

ADR380/

RL

ADR381

GND

3

VOUT

Figure 30. ADR380/ADR381 for Precision High Current Voltage Source

Rev. C | Page 13 of 16

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