3

Figure 2: Divide by 1 SELECT Mode

SENSOR is a PNP comparator input which accepts a sine wave

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

rent is limited to 1.5mA. It has an active clamp set to zero volts to

prevent negative input voltages from disrupting normal opera-

current is limited to 1.5mA max using a series resistor of 100k½.

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 Transition States section.

The transition states occur as indicated in Table 1 without any

intermediate states permitted.

Table 1: Transition States

The polarity definition for the coil driver outputs is as follows:

Connect

Connect

Polarity

Coil +

Coil -

Positive (+)

Gnd

Negative (-)

Gnd

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

Circuit Operation

Speed Sensor Input

Coil Driver Outputs

Divider Select Input

Short

Circuit

Sense

Resistor

Coil

Short

Circuit

Sense

Resistor

Gnd

Q3

Q4

Q1

Q2

Overvoltage

and

Short

Circuit

Protection

Package Pin Description

PACKAGE PIN #

PIN SYMBOL

FUNCTION

Figure 1: Coil Driver Output

Figure 3: Divide by 2 SELECT Mode

Output State Table

State

Coil A

Coil B

0+

+

1

OFF

+

2-

+

3

-

OFF

4-

-

5

OFF

-

6+

-

7

+

OFF

DIVIDE BY ONE MODE SELECT = V

CC

DIVIDE BY TWO MODE SELECT = Gnd

8L PDIP

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.

Supply Voltage.