or r
ot ive
M r
D
SLA7050M
UNIPOLAR STEPPER-MOTOR
TRANSLATOR/PWM DRIVER
Combining low-power CMOS logic with high-current, high-voltage
power FET outputs, the SLA7050M translator/driver provides complete
control and drive for a two-phase unipolar stepper motor with internal
fixed off time, pulse-width modulation (PWM) control of the output
current in a power multi-chip module (PMCM™).
The CMOS logic section provides the sequencing logic, direction,
full/half-step control, synchronous/asynchronous PWM operation, and
a “sleep” function. The minimum CLOCK input is an ideal fit for
applications where a complex µP is unavailable or overburdened. TTL
or LSTTL may require the use of appropriate pull-up resistors to ensure
a proper input-logic high. For PWM current control, the maximum
output current is determined by the user’s selection of a reference
voltage and sensing resistor. The NMOS outputs are capable of sinking
up to 1 A and withstanding 46 V in the off state. Ground-clamp and
flyback diodes provide protection against inductive transients. Special
power-up sequencing is not required.
Full-step (2 phase) and half-step operation are externally selectable.
Two-phase drive energizes two adjacent phases in each detent position
(AB-BC-CD-DA). This sequence mode offers an improved torque-
speed product, greater detent torque, and is less susceptable to motor
resonance. Half-step excitation alternates between the one-phase and
two-phase modes (A-AB-B-BC-C-CD D-DA), providing an eight-step
sequence.
The SLA7050M is supplied in an 18-pin single in-line power-tab
package with leads formed for vertical mounting (suffix LF871) or
horizontal mounting (suffix LF872). The tab is at ground potential and
needs no insulation. For high-current or high-frequency applications,
external heat sinking may be required. This device is rated for continu-
ous operation between -20°C and +85°C.
Data Sheet
28210.2
A
BSOLUTE
M
AXIMUM
R
ATINGS
Driver Supply Voltage, V
BB
................
46 V
Load Supply Voltage, V
M
..................
46 V
Output Current, I
O
..........................
1.0 A*
Logic Supply Voltage, V
DD
...............
7.0 V
Logic Input Voltage Range,
V
I
...........................
-0.3 V to V
DD
+ 0.3 V
Sense Voltage, V
S
........................
±2.0 V†
Reference Input Voltage Range,
V
REF ...................................
-0.3 V to V
DD
+ 0.3 V
Package Power Dissipation,
P
D
........................................
See Graph
Junction Temperature, T
J
.............
+150°C
Operating Temperature Range,
T
A
.................................
-20°C to +85°C
Storage Temperature Range,
T
S
...............................
-30°C to +150°C
* Output current rating may be limited by duty cycle,
ambient temperature, and heat sinking. Under any set of
conditions, do not exceed the specified current rating or
junction temperature.
† Internal filtering provides protection against transients
during the first 1 µs of the current-sense pulse.
F
EATURES
1 A Output Rating
Internal Sequencer for Full or Half-Step Operation
PWM Constant-Current Motor Drive
Cost-Effective, Multi-Chip Solution
100 V, Avalanche-Rated NMOS
Low
r
DS(on)
NMOS Outputs (700 m
Ω
typical)
Advanced, Improved Body Diodes
Half-Step and Full-Step Unipolar Drive
Inputs Compatible with 3.3 V or 5 V Control Signals
Sleep Mode
Internal Clamp Diodes
Always order by complete part number, e.g.,
SLA7050MLF871
.
Sanken Power Devices
from Allegro MicroSystems
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