CS8441 Datasheet, PDF (3/4 Pages) Cherry Semiconductor Corporation – 85mA Dual H-Bridge Odometer Driver with Divide by Select

Package Pin Description
PACKAGE PIN #
8L PDIP
1
2
3
4
5
6
7
8
PIN SYMBOL
FUNCTION
Gnd
COILA+
COILA-
SENSOR
SELECT
COILB-
COILB+
V_CC
Ground connection.
Output stage, when active, this pin supplies current to COIL A.
Output stage, when active, this pin supplies current to COIL A.
Input signal from wheel speed or engine rpm.
Selects divide by 1 or divide by 2 mode.
Output stage, when active, this pin supplies current to COIL B.
Output stage, when active, this pin supplies current to COIL B.
Supply Voltage.
Circuit Operation
Speed Sensor Input
SENSOR is a PNP comparator input which accepts a sine wave
input or a square wave input. This input is protected from excur-
sions above V_CC as well as any below ground, as long as the cur-
rent is limited to 1.5mA. It has an active clamp set to zero volts to
prevent negative input voltages from disrupting normal opera-
tion. The sensor input can withstand 150V_DC as long as the input
current is limited to 1.5mA max using a series resistor of 100k½.
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 Transition States section.
The transition states occur as indicated in Table 1 without any
intermediate states permitted.
Table 1: Transition States
State
0
1
2
3
4
5
6
7
Output State Table
Coil A
+
OFF
-
-
-
OFF
+
+
Coil B
+
+
+
OFF
-
-
-
OFF
The polarity definition for the coil driver outputs is as follows:
Polarity
Positive (+)
Negative (-)
Connect
Coil +
V_CC
Gnd
Connect
Coil -
Gnd
V_CC
Short
Circuit
V_CC
Sense
Q1
Q3
Resistor
Overvoltage
and
Short
Circuit
Coil Protection
Q2
Q4
Short
Circuit
Gnd
Sense
Resistor
Figure 1: Coil Driver Output
DIVIDE BY ONE MODE SELECT = VCC
Figure 2: Divide by 1 SELECT Mode
DIVIDE BY TWO MODE SELECT = 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
Figure 3: Divide by 2 SELECT Mode
3