REF01/REF02/REF03

Rev. K | Page 16 of 20

APPLICATIONS INFORMATION

BASIC REFERENCE APPLICATION

Figure 38 shows the basic configuration for any REF0x device.

Input and output capacitance values can be tailored for

performance, provided they follow the guidelines described

in the Input and Output Capacitors section.

U1

REF01/

REF02/

REF03

C2

0.1µF

C1

0.1µF

TEMP TRIM

GND

Figure 38. Basic Reference Application

LOW COST CURRENT SOURCE

Unlike most references, the quiescent current of the REF0x

series remains constant with respect to the load current (refer to

Figure 22)

. As a result, a simple, low cost current source can be

constructed by configuring the reference as shown in Figure 39.

REF01/

REF02/

REF03

GND

Figure 39. Simple Current Source

this circuit should be limited to low precision, general-purpose

applications.

PRECISION CURRENT SOURCE WITH ADJUSTABLE

OUTPUT

A higher-precision current source can be implemented with the

circuit shown in Figure 40.

U2

+12V

–12V

W

B

A

U1

REF02

TEMP TRIM

GND

V–

V+

OP1177

AD5201

+12V

1k

Ω

1k

Ω

100k

Ω

Figure 40. Programmable 0 mA to 5 mA Current Source

By adding a mechanical or digital potentiometer, this circuit

becomes an adjustable current source. If a digital potentiometer

is used, the load current is simply the voltage across terminal B

to terminal W of the digital potentiometer divided by the value

[]

A

SET

REF

L

R

D

V

I

×

=

where

D is the decimal equivalent of the digital potentiometer

input code.

A dual-supply op amp should be used since the ground

potentiometer is swung from zero-scale to full-scale.

PRECISION BOOSTED OUTPUT REGULATOR

The output current sourcing capability of the REF0x series can

be boosted by using an external op amp and MOSFET, as shown

in Figure 41.

U2

15V

N1

200

Ω

U1

REF01/

REF02/

REF03

TEMP TRIM

GND

V–

V+

OP1177

2N7002

1µF

1000pF

100

Ω

100

Ω

Figure 41. Precision Boosted Output Regulator

through N1, thereby sourcing the load current directly from the

shown, this circuit can source up to 50 mA with an input volt-

age of 15.0 V. The circuit’s current sourcing capability can be

further increased by replacing N1 with a higher-power MOSFET.