Cherry Semiconductor CS3717AGNF16 Datasheet
1
Features
■
Full/Half /Quarter Step
Operation
■
Output Current Up to 1 A
■
Motor Supply Voltage 10V
to 46V
■ Integrated Bootstrap
Lowers Saturation Voltage
■ Built In Protection Diodes
■ Externally Selectable
Current Level
■ Digital or Analog Control
of Output Current Level
■ Thermal Overload
Protection
■ Minimum External
Components
Package Options
CS3717A
1A H-Bridge Stepper Motor Driver
CS3717A
Description
The CS3717A controls and drives
one phase of a bipolar stepper
motor with chopper control of the
phase current. Current levels may
be selected in three steps by means
of two logic inputs which select one
of three current comparators. When
both of these inputs are high the
device is disabled. A separate logic
input controls the direction of current flow. A monostable, programmed by an external RC network, sets the current decay time.
The power section is a full H-bridge
driver with four internal clamp
diodes for current recirculation. An
external connection to the lower
emitters is available for the insertion of a sensing resistor. Two
CS3717AÕs and several external
components form a complete stepper motor drive subsystem.
The recommended operating ambient temperature range is from 0 to
70¡C.
The CS3717A is supplied in a 16
lead PDIP.
Block Diagram
16L PDIP
(Internally Fused Leads)
1
OUTB
Pulse
V
DD
B
Gnd
V
CC
IN1
DIRECTION
Sense
OUTA
V
DD
A
Gnd
Gnd
V
REF
Comp In
IN0
Gnd
Power Supply Voltage (V
DDA
, V
DDB
)............................................................50V
Logic Supply Voltage (VCC)..............................................................................7V
Logic Input Voltage (IN0, IN1, DIRECTION)................................................6V
Comparator Input............................................................................................V
CC
Reference Input Voltage..................................................................................15V
Output Current (DC Operation)...................................................................1.2A
Storage Temperature .................................................................Ð55¡C to +150¡C
Operating Junction Temperature.............................................Ð40¡C to +150¡C
Lead Temperature Soldering
Wave Solder(through hole styles only) ............10 sec. max, 260¡C peak
Absolute Maximum Ratings
Cherry Semiconductor Corporation
2000 South County Trail, East Greenwich, RI 02818
Tel: (401)885-3600 Fax: (401)885-5786
Email: info@cherry-semi.com
Web Site: www.cherry-semi.com
A Company
¨
Rev. 4/29/99
IN0
DIRECTIONIN1
V
DD
OUTA
A
OUTB
V
DD
B
V
CC
V
REF
Gnd
6KW
223W
223W
105W
00 01 10 11
+
-
+
-
+
-
THERMAL
SHUTDOWN
MONO-
STABLE
PulseComp In Sense
2
Electrical Characteristics: Refer to the test circuit VDD= 36V, VCC= 5V, TA= 25¡C; unless otherwise specified.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
CS3717A
Supply Voltage 10 46 V
Logic Supply Voltage 4.75 5.25 V
Logic Supply Current 7 15 mA
Reference Input Current V
REF
= 5V 0.75 1.00 mA
■ Logic Inputs
Input Low Voltage 0.8 V
Input High Voltage 2 V
Low Voltage Input Current V
IN
= 0.4V (DIRECTION) -100 µA
(IN0, IN1) -400 µA
High Voltage Input Current VIN= 2.4V 10 µA
■ Comparators
Comparator Low V
REF
= 5V IN0 = Low 66 80 94 mV
Threshold Voltage IN1 = High
Comparator Medium V
REF
= 5V IN0 = High 236 251 266 mV
Threshold Voltage IN1 = Low
Comparator High V
REF
= 5V IN0 = Low 396 416 436 mV
Threshold Voltage IN1 = Low
Comparator Input Current ±20 µA
Cutoff Time R
T
= 56k½ CT= 820pF 27 37 µs
Turn Off Delay 2µs
Output Leakage Current IN0 =IN1 = High 100 µA
■ Source Diode-Transistor Pair
Saturation Voltage I
MOTOR
= -0.5A conduction period 1.7 2.1 V
recirculation period 1.10 1.35 V
Saturation Voltage I
MOTOR
= -1A conduction period 2.1 2.8 V
recirculation period 1.7 2.5 V
Leakage Current V
S
= 46V 300 µA
Diode Forward Voltage I
MOTOR
= -0.5A 1.00 1.25 V
I
MOTOR
= -1A 1.3 1.7 V
■ Sink Diode-Transistor Pair
Saturation Voltage I
MOTOR
= 0.5A 1.20 1.45 V
I
MOTOR
= 1A 1.75 2.30 V
Leakage Current V
S
= 46V 300 µA
Diode Forward Voltage I
MOTOR
= 0.5A 1.1 1.5 V
I
MOTOR
= 1A 1.4 2.0 V
3
Package Pin Description
PACKAGE PIN # PIN SYMBOL FUNCTION
CS3717A
Truth Table
IN0 IN1 Output Current
H H No Current
L H Low Current
H L Medium Current
L L High Current
16L
(Internally Fused Leads)
1 OUT B Output connection with OUTA. The output stage is a ÒHÓ bridge
formed by four transistors and four diodes suitable for switching
applications.
2 Pulse A parallel RC network connected to this pin sets the OFF time of
the lower power transistors. The pulse generator is a monostable
triggered by the rising edge of the output of the comparators
(t
OFF
= 0.69 RTCT).
3V
DDB
Supply voltage input for half output stage.
4, 5, 12, 13 Gnd Ground connection. Also conducts heat from die to printed
circuit copper.
6V
CC
Supply voltage input for logic circuitry.
7 IN1 This pin and IN0 are logic inputs which select the outputs of the
three comparators to set the current level. Current also depends on
the sensing resistor and reference voltage. See truth table.
8 DIRECTION This TTL-compatible logic input sets the direction of current
flow through the load. A high level causes current to flow from
OUTA (source) to OUTB (sink). A Schmitt trigger on this input
provides good noise immunity and a delay circuit prevents output stage short circuits during switching.
9 IN0 See IN1.
10
Comp In
Input connected to the three comparators. The voltage across the
sense resistor is fed back to this input through the low pass filter
RCCC. The lower power transistors are disabled when the sense
voltage exceeds the reference voltage of the selected comparator.
When this occurs the current decays for a time set by RTCT,
t
OFF
= 0.69 RTCT.
11 V
REF
A voltage applied to this pin sets the reference voltage of the
three comparators, thus determining the output current (also
dependent on R
Sense
and the two inputs IN 0 and IN 1).
14 V
DDA
Supply voltage input for half output stage.
15 OUT A See OUTB.
16 Sense Connection to lower emitters of output stage for insertion of
current sense resistor.
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