CS4161 Datasheet, PDF (3/4 Pages) Cherry Semiconductor Corporation – 85mA Dual H-Bridge Odometer Driver with Divide by Select and UVLO

Circuit Operation
Speed Sensor Input
SENSOR is a PNP comparator input which accepts either a sine
wave 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 the 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
Divider Select Input
The speed sensor input frequency is either divided by one or divid-
ed by two depending on the state of the SELECT input as follows:
Logic 0 = divide by 2
Logic 1 = divide by 1
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
Figure 2: Divide by 1 SELECT Mode
DIVIDE BY TWO MODE SELECT = Gnd
Figure 3: Divide by 2 SELECT Mode
Odometer Application Diagram
COIL A
COIL B
C1 - 10µF
C2 - 0.1µF
C3 - 0.01µF
R1 - 3.9½, 500mW
R2 - 100k½
R3 - 15k½
D1 - 1A, 600PIV
Z1 - 50V, 500mW
COIL A - 210 ±12½, 80mH
COIL B - 210 ±12½, 80mH
IGN
D1 _R1
Buffered Speed Signal
(Open Collector Drive)
Z1
R3
R2
COILA+ COILAÐ COILB+ COILBÐ
CS4161
SENSOR
V_CC
SELECT
Gnd
C1
C2
C3
3