CS8442 Datasheet, PDF (1/4 Pages) Cherry Semiconductor Corporation – 85mA Dual H-Bridge Odometer Driver with Buffered Speed Signal Output

CS8442
Stepper Motor Driver
with Buffered Speed Signal Output
Description
Features
The CS8442 is a stepper motor
driver that implements an H-
bridge design to drive two coils in
an eight step sequence each revo-
lution. Each H-bridge is capable of
delivering 85mA to the load.
The sequencer function insures
that the odometer is monotonic
and that cross-conduction of each
H bridges does not occur. Before
the beginning of each sequence,
both bridges are turned off. This
“dead zone” minimizes the fly
back energy generated in the
inductive loads. In addition, on
board clamp diodes across each
output protect the output drive
transistors from excessive fly back
voltages.
The CS8442 is fault protected
against reverse battery, short cir-
cuit, and over voltage conditions.
If a fault is detected, the IC shuts
down.
The buffered speed signal output
(SENSOR OUT) is an open collec-
tor NPN capable of driving a
4.7kΩ load connected to a 5V sup-
ply. The signal is a buffered,
inverted version of the speed sen-
sor input voltage (SENSOR IN).
The input voltage can be either a
sine or square wave form.
Absolute Maximum Ratings
Supply Voltage (V_CC) (continuous) -40˚C to +105˚C ..................–0.5 to 24V
(100ms pulse transient) -40˚C to +105˚C ......................–0.5 to 60V
Input Voltage (V_IN) ..............................................................–0.3 to V_CC +0.3V
Storage Temperature Range (T_STG)......................................–65°C to +150°C
Junction Temperature.............................................................–40°C to +150°C
Speed Sensor Output .....................................................................................7V
ESD (Human Body Model) .........................................................................2kV
Lead Temperature Soldering
Wave Solder (through hole styles only) ........10 sec. max, 260°C peak
Block Diagram
SENSOR
IN
Input
Comp.
Coil
Driver
A
COILA+
COILA-
s Buffered Speed Sensor
Output
s No Cross-conduction in
either H-bridge
s Guaranteed Monotonic
s On Chip Flyback Diodes
s Fault Protection
Overvoltage
Short Circuit Protection
Load Dump Protection
to 60V
Package Options
8 Lead PDIP
Gnd 1
COILA+
COILA–
SENSOR
IN
V_CC
COILB+
COILB–
SENSOR
OUT
SENSOR
OUT
December, 2001 - Rev. 2
Sequencer
Overvoltage
and Short
Circuit
Protection
Coil
Driver
B
COILB+
COILB-
1
ON Semiconductor
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885–3600 Fax: (401)885–5786
N. American Technical Support: 800-282-9855
Web Site: www.cherry–semi.com