A3974SED Allegro Microsystems Inc, A3974SED Datasheet - Page 2

• Manufacturer Part Number: A3974SED
• Description: IC MOTOR DRVR PWM DUAL 44-PLCC
• Manufacturer: Allegro Microsystems Inc

Specifications of A3974SED

• Applications: DC Motor Driver
• Number Of Outputs: 2
• Current - Output: ±1.5A
• Voltage - Load: 15 V ~ 50 V
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 44-LCC (J-Lead)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Features and Benefits
▪ ±1.5 A, 50 V continuous output rating
▪ Low r
▪ Programmable slow, fast, and mixed current-decay modes
▪ Serial-interface controls chip functions
▪ Synchronous rectification for low power dissipation
▪ Internal UVLO and thermal shutdown circuitry
▪ Crossover-current protection
▪ Sleep and idle modes
Package: 44-pin PLCC with internally
fused pins (suffix ED)
29319.35C
DS(on)
Not to scale
DMOS output drivers
DMOS Dual Full-Bridge PWM Motor Driver
STROBE
SUPPLY
CLOCK
LOGIC
DATA
REF
REF
GND
GND
GND
NC
NC
1
2
10
11
12
13
15
14
16
17
7
8
9
V
DD
Pin-out Diagram
PWM TIMER
PROGRAM
PWM TIMER
PROGRAM
Description
Designed for pulse width modulated (PWM) current control
of two DC motors, the A3974 is capable of output currents to
±1.5 A and operating voltages to 50 V. Internal fixed off-time
PWM current-control timing circuitry can be programmed via
a serial interface to operate in slow, fast, and mixed current-
decay modes.
Independent ENABLE input terminals are provided for use
in controlling the speed and torque of each DC motor with
externally applied PWM control signals.
Synchronous rectification circuitry allows the load current
to flow through the low
during the current decay. This feature will eliminate the need
for external clamp diodes in most applications, saving cost
and external component count, while minimizing power
dissipation.
Internal circuit protection includes thermal shutdown with
hysteresis, undervoltage monitoring of V
pump, and crossover-current protection. Special power-up
sequencing is not required.
The A3974 is supplied in a 44-pin plastic PLCC with 3 internally
fused pins on each side, for maximum heat dissipation. The fused
pins are at ground potential and need no electrical isolation.
V
V
BB2
BB1
LOGIC
LOGIC
Dwg. PP-073
39
38
37
36
35
34
33
32
31
30
29
NC
CP2
CP1
CP
GND
GND
GND
OSC
SLEEP
V
NC
REG
r
DS(on)
of the DMOS output driver
DD
and the charge
A3974