AD534

Rev. C | Page 16 of 20

AD534

SF

OUT

+15V

500Ω

39kΩ

2kΩ

82kΩ

2.2kΩ

–15V

CONTROL INPUT,

+

–

(= R)

ADJ

1kHz

0.01

(= C)

ADJ 8kHz

3pF to 30pF

2

3

7

AD211

+15V

OUTPUT

±15V APPROX.

PINS 5, 6, 8 TO +15V

PINS 1, 4 TO –15V

f =

×

40

1

CR = 1kHz PER VOLT

WITH VALUES SHOWN

CALIBRATION PROCEDURE:

WILL TYPICALLY BE WITHIN ±0.1% OF FS FORANY OTHER INPUT.

DUE TO DELAYS IN THE COMPARATOR, THIS TECHNIQUE IS NOT SUITABLE

FOR MAXIMUM FREQUENCIES ABOVE 10kHz. FOR FREQUENCIES ABOVE

10kHz THE AD537 VOLTAGE-TO-FREQUENCY CONVERTER IS RECOMMENDED.

A TRIANGLE-WAVE OF ±5V PK APPEARS ACROSS THE 0.01µF CAPACITOR: IF

USED AS AN OUTPUT, A VOLTAGE-FOLLOWER SHOULD BE INTERPOSED.

Figure 26. Differential Input Voltage-to-Frequency Converter

AD534

AD741J

SF

OUT

+15V

+15V

10kΩ

10kΩ

10kΩ

20kΩ

10kΩ

10kΩ

ZERO

ADJ

10MΩ

–15V

10µF

NONPOLAR

10µF SOLID Ta

20kΩ

AD741K

5kΩ

+

RMS + DC

MODE

AC RMS

INPUT

5V RMS FS

±10V PEAK

OUTPUT

0V TO 5V

MATCHED TO 0.025%

CALIBRATION PROCEDURE:

WITH MODE SWITCH IN ‘RMS + DC’ POSITION, APPLY AN INPUT OF +1.00V DC.

ADJUST ZERO UNTIL OUTPUT READS SAME AS INPUT. CHECK FOR INPUTS

OF ±10V; OUTPUT SHOULD BE WITHIN ±0.05% (5mV).

ACCURACY IS MAINTAINED FROM 60Hz TO 100kHz, AND IS TYPICALLY HIGH

PROVIDED THAT THE PEAK INPUT IS NOT EXCEEDED, CREST FACTORS UP

TO AT LEAST 10 HAVE NO APPRECIABLE EFFECT ON ACCURACY.

INPUT IMPEDANCE IS ABOUT 10kΩ; FOR HIGH (10MΩ) IMPEDANCE, REMOVE

MODE SWITCH AND INPUT COUPLING COMPONENTS.

FOR GUARANTEED SPECIFICATIONS THE AD536A AND AD636 ARE OFFERED

AS A SINGLE PACKAGE RMS-TO-DC CONVERTER.

Figure 27. Wideband, High-Crest Factor, RMS-to-DC Converter