REF102

7

SBVS022B

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OPTIONAL NOISE REDUCTION

The high-frequency noise of the REF102 is dominated by the

zener diode noise. This noise can be greatly reduced by

connecting a capacitor between the Noise Reduction pin and

the figure on page 1) and attenuates the high-frequency

noise generated by the zener. Figure 5 shows the effect of a

1

µF noise reduction capacitor on the high-frequency noise of

frequency of about 22Hz. The result is a reduction in noise

from about 800

µV

reduction is required, use the circuit in Figure 14.

APPLICATIONS INFORMATION

High accuracy, extremely low drift, outstanding stability, and

low cost make the REF102 an ideal choice for all instrumen-

tation and system reference applications. Figures 6 through

14 show a variety of useful application circuits.

6

b) Precision –10V Reference.

a) Resistor Biased –10V Reference

R

S

I

L

4

REF102

2

−10V Out

See SBVA008 for more detail.

V+ (1.4V to 26V)

1.4mA <

< 5.4mA

(5V

−I

R

S

2

6

4

10V

OPA227

R

1

2k

Ω

C

1000pF

1

−10V Out

−15V

REF102

V+ (1.4V to 26V)

FIGURE 6. –10V Reference Using a) Resistor or b) OPA227.

NO C

N

C

FIGURE 5. Effect of 1

µF Noise Reduction Capacitor on