60/120

EN

F/R

QS

PWM

GND

BRK

TACH

FAULT

SQFP-48

1

2

3

4

5

6

7

8

9

10

11

12

46 45 44 43 42 41 40 39 38 37

15 16 17 18 19 20 21 22 23 24

36

35

34

33

32

31

30

29

28

27

26

Top View

48 47

13 14

25

Si9979

Vishay Siliconix

www.vishay.com

4

Document Number: 70012

S-41209—Rev. E, 21-Jun-04

PIN CONFIGURATION AND ORDERING INFORMATION

ORDERING INFORMATION

Standard

Part Number

Lead (Pb)-Free

Part Number

Temperature

Range

Package

Si9979CS

Si9979CS—E3

0 to 70_C

SQFP-48

Si9979DS

Si9979DS—E3

−40 to 85_C

SQFP-48

NOTE: Si9979CS and Si9979DS are supplied in trays.

PIN DESCRIPTION

intended to be driven by open collector Hall effect switches.

eliminates the need for external pull up resistors.

Pin 4: 60/120

The 60/120 input allows the use of the Si9979 with either a 60_

or 120_ commutation sensor spacing. An internal pull up

spacing. 120_ spacing is selected by pulling this input to

ground.

Pin 5: EN (Enable)

A logic “1” on this input allows commutation of the motor. This

is the default condition as this pin is pulled up internally. When

this pin is pulled to ground, all gate drive outputs are turned off.

Pin 6: F/R (Forward/Reverse)

A logic “1” on this input selects commutation for motor rotation

in the “forward” direction. This is the default condition as this

pin is pulled up internally. When this pin is pulled to ground, the

commutation sensor logic levels are inverted internally,

causing reverse rotation.

Pin 7: QS (Quadrature Select)

This input determines whether the bottom MOSFETs or both

bottom and top MOSFETs switch in response to the PWM

signal. A logic “1” on this input enables only the bottom

MOSFETs. This is the default condition as this pin is pulled up

internally. When this pin is pulled to ground, both the bottom

and top MOSFETs are enabled.

Pin 8: PWM

An open collector (drain) or TTL compatible signal is applied

to this input to control the motor speed. The QS input

determines which MOSFETs are switched in response to the

PWM signal. If no PWM signal is being used, this input is left

open. It is pulled up internally, which allows the MOSFETs to

follow the commutation sequence.