SM3470BB

SEIKO NPC CORPORATION - 7

FUNCTIONAL DESCRIPTION

Adjustment Circuit

The adjustment circuit block accepts displacement detection 2-phase analog signals from the encoder (A-phase and B-phase) and the

zero-point detection analog signal (Z-phase) and perform offset adjustment.

The offset adjustment is set according to register data. For details, see “AnalogAdjustment BitAssignment.”

(monitoring IO1, IO2, IO3), then adjust the offsets (FAN, FBN, FZN) for the non-inverting output amplifier (monitoring DA, DB, DZ).

mode.

AMP

AMP

A(cos)

AN(-cos)

Offset

adjustment

data

FA[7:0]

FAN[4:0]

AMP

AMP

B(sin)

BN(-sin)

FB[7:0]

FBN[4:0]

AMP

AMP

Z

ZN

FZ[5:0]

FZN[2:0]

ANsig(-cos)

Asig(cos)

BNsig(-sin)

Bsig(sin)

ZNsig

Zsig

×(-1)

×(-1)

×(-1)

Offset

adjustment

data

Offset

adjustment

data

Offset

adjustment

data

Offset

adjustment

data

Offset

adjustment

data

1800

2000

2200

2400

2600

2800

3000

3200

0

32

64

96

128 160 192 224 256

Offset voltage adjustment data FA,(FB)

A(B)phase inverting out put

1800

2000

2200

2400

2600

2800

3000

3200

0

8

16

24

32

40

48

56

64

Offset voltage adjustment data FZ

Z phase inverting output

2450

2460

2470

2480

2490

2500

2510

2520

2530

2540

2550

0

4

8

12

1620

242832

Offset voltage adjustment data FAN,FBN

A(B)phase non-inverting output

2470

2475

2480

2485

2490

2495

2500

2505

2510

2515

2520

2525

01

23

45

67

8

Offset voltage adjustment data FZN

Z phase non-inverting output