8905

3-PHASE BRUSHLESS DC

MOTOR CONTROLLER/DRIVER

115 Northeast Cutoff, Box 15036

Worcester, Massachusetts 01615-0036 (508) 853-5000

D0- Sleep/Run Mode; LOW = Sleep, HIGH = Run

This bit allows the device to be powered down when not in

use.

D1- Step Mode; LOW = Normal Operation, HIGH = Step Only

When in the step-only mode the back-EMF commutation

circuitry is disabled and the power outputs are commutated

by the start-up oscillator. This mode is intended for device

and system testing.

D2- Brake; LOW = Run, HIGH = Brake.

D3 and D4-These two bits set the output current limit:

D3

D4

Current Limit

0

0

Saturated

01

1 A

1

0

800 mA

1

1

600 mA

to set desired motor speed.

Bit Number

Count Number

D5

16

D6

32

D7

64

D8

128

D9

256

D10

512

D11

1 024

D12

2 048

D13

4 096

D14

8 192

D15

16 384

D16

32 768

D17

65 536

D18

131 072

SERIAL PORT BIT DEFINITIONS

D19-Speed-control mode switch;

LOW = internal once-around speed signal,

HIGH = external index data.

D20 and D21-These bits program the number of motor poles

D20

D21

Motor Poles

00

8

01

–

10

16

11

12

D22 and D23-Control the multiplexer for DATA OUT:

D22

D23

Data Out

0

0

TACH (once around or index)

0

1

Thermal Shutdown

1

0

SYNC

1

1

FCOM