CS8441

http://onsemi.com

3

Characteristic

Unit

Max

Typ

Min

Test Conditions

Short Circuit Protection

Short Circuit Threshold

I Coil A + I Coil B

–

–

275

400

mA

Short Circuit Turn–Off Delay

–

–

5.0

–

µs

PACKAGE PIN DESCRIPTION

PACKAGE PIN #

DIP–8

PIN SYMBOL

FUNCTION

1

GND

Ground connection.

2

COILA+

Output stage, when active, this pin supplies current to COIL A.

3

COILA–

Output stage, when active, this pin supplies current to COIL A.

4

SENSOR

Input signal from wheel speed or engine rpm.

5

SELECT

Selects divide by 1 or divide by 2 mode.

6

COILB–

Output stage, when active, this pin supplies current to COIL B.

7

COILB+

Output stage, when active, this pin supplies current to COIL B.

8

Supply voltage.

CIRCUIT OPERATION

SPEED SENSOR INPUT

SENSOR is a PNP comparator input which accepts a sine

wave or a square wave input. This input is protected from

as the current is limited to 1.5 mA. It has an active clamp set

to zero volts to prevent negative input voltages from

disrupting normal operation. The sensor input can withstand

max. using a series resistor of 100 k

Ω.

COIL DRIVER OUTPUTS

Simultaneously energizing the source and sink on either

leg is not permitted, i.e. Q1 & Q2 or Q3 & Q4 cannot be

energized simultaneously.

Circuit function is not affected by inductive transients due

to coil loads as specified in the Transition States section.

The transition states occur as indicated in Table 1 without

any intermediate states permitted.

Table 1. Transition States

State

Coil A

Coil B

0

+

+

1

OFF

+

2

–

+

3

–

OFF

4

–

–

5

OFF

–

6

+

–

7

+

OFF

The polarity definition for the coil driver outputs is as

follows:

Polarity

Connect Coil +

Connect Coil –

Positive (+)

GND

Negative (–)

GND

DIVIDER SELECT INPUT

The speed sensor input frequency is divided by one or

divided by two by connecting the divider select input, (Pin

5) as follows:

Logic 0 = divide by 2.

Logic 1 = divide by 1.