3977

MICROSTEPPING DMOS DRIVER

WITH TRANSLATOR

www.allegromicro.com

3

Table 1. Microstep Resolution Truth Table

Resolution

L

L

Full step (2 phase)

H

L

Half step

L

H

Quarter step

H

H

Eighth step

A3977xLP

(TSSOP)

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

LOAD

SLEEP

ENABLE

PGND

STEP

RESET

SR

LOAD

HOME

DIR

PFD

AGND

REF

LOGIC

SUPPLY

÷8

REG

Dwg. PP-075

A3977xLP ......................... 28

A3977xED ........................ 32

A3977xLP ......................... 33

*

Measured on JEDEC standard “High-K” four-layer board.

† Measured on typical two-sided PCB with three square inches

50

75

100

125

150

5.0

1.0

0

AMBIENT TEMPERATURE IN

°°°°C

4.0

3.0

2.0

25

SUFFIX '–LP',

R

°C/W†

Dwg. GP-018-2A

SUFFIX '–ED', R

°C/W†

SUFFIX '–LP', R

°C/W*

SUFFIX 'K–'

SUFFIX 'S–'