A4973_16 Datasheet, PDF (1/11 Pages) Allegro MicroSystems – Full-Bridge PWM Motor Driver

A4973
Full-Bridge PWM Motor Driver
Features and Benefits
▪ ±1.5 A continuous output current
▪ 50 V output voltage rating
▪ 3 V to 5.5 V logic supply voltage
▪ Internal PWM current control
▪ Fast and slow current-decay modes
▪ Sleep (low current consumption) mode
▪ Internal transient-suppression diodes
▪ Internal thermal shutdown circuitry
▪ Crossover current and UVLO protection
Packages:
Package B, 16-pin DIP
with exposed tabs
Package LB, 16-pin SOIC
with internally fused pins
Not to scale
Description
Designed for bidirectional pulse width modulated (PWM)
current control of inductive loads, the A4973 is capable of
continuous output currents to ±1.5 A and operating voltages
to 50 V. Internal fixed off-time PWM current-control circuitry
can be used to regulate the maximum load current to a desired
value. The peak load current limit is set by the user’s selection
of an input reference voltage and external sensing resistor. The
fixed off-time pulse duration is set by a user- selected external
RC timing network. Internal circuit protection includes thermal
shutdown with hysteresis, transient-suppression diodes, and
crossover current protection. Special power-up sequencing is
not required.
With the ENABLE input held low, the PHASE input controls
load current polarity by selecting the appropriate source and
sink driver pair. The MODE input determines whether the
PWM current-control circuitry operates in a slow current-decay
mode (only the selected source driver switching) or in a fast
current-decay mode (selected source and sink switching). A
user-selectable blanking window prevents false triggering of
the PWM current-control circuitry. With the ENABLE input
held high, all output drivers are disabled. A sleep mode is
provided to reduce power consumption.
Continued on the next page…
Functional Block Diagram
LOGIC
SUPPLY
6 V CC
MODE 14
PHASE 7
ENABLE 8
BRAKE ¹
GROUND
4
5
SLEEP &
STANDBY MODES
UVLO
& TSD
9
10 15
16
V BB
BLANKING
V _CC
PWM LATCH
R
Q
S
RC
3
CT
RT
+–
V _TH
2
2
REF
11
SENSE
RS
12
13
GROUND
4973DS, Rev. 1