REV. B

–5–

AD2S99

AD2S99/AD2S90 TYPICAL CONFIGURATION

Figure 3 shows a typical circuit configuration for the AD2S99

Oscillator and the AD2S90 Resolver-to-Digital Converter. The

maximum level of the SIN and COS input signals to the

AD2S90 should be 2 V rms

±10%. All the analog ground sig-

nals should be star connected to the AD2S90 AGND pin. If

shielded twisted pair cables are used for the resolver signals, the

shields should also be terminated at the AD2S90 AGND pin.

The SYNREF output of the AD2S99 should be connected to

the REF input pin of the AD2S90 via a 0.1

µF capacitor with a

100 k

Ω resistor to GND. This is to block out any dc offset in

the SYNREF signal. For more detailed information please refer

to the AD2S90 data sheet.

NC = NO CONNECT

NC

SIN

NC

DGND

COS

EXC

EXC

NC

AGND

NC

19

31

2

20

4

5

8

6

7

12 13

911

10

18

17

14

16

15

TOP VIEW

(Not to Scale)

AD2S99

19

3

1

2

20

4

5

8

6

7

12

13

9

11

10

18 17

14

16 15

4.7µF

4.7µF

0.1µF

0.1µF

COS

SIN

REF

S2

S4

S3

S1

R4

R2

RESOLVER

REF

COS

AGND

SIN

SIN LO

DGND

AD2S90

TOP VIEW

(Not to Scale)

0.1µF

100k

Ω

0.1µF

50k

Ω

4.7µF

0.1µF

4.7µF

SEL2 = GND

COS LO

S4

S3

S1

S2

POWER

RETURN

Figure 3. AD2S99 and AD2S90 Example Configuration