A3958SB Allegro Microsystems Inc, A3958SB Datasheet - Page 2

• Manufacturer Part Number: A3958SB
• Description: IC MOTOR DRIVER PWM FULL 24-DIP
• Manufacturer: Allegro Microsystems Inc

Specifications of A3958SB

• Applications: PWM Motor Driver
• Number Of Outputs: 1
• Current - Output: ±2A
• Voltage - Load: 20 V ~ 50 V
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Through Hole
• Package / Case: 24-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Features and Benefits
▪ ±2 A, 50 V continuous output rating
▪ Low r
▪ Programmable mixed, fast, and slow current-decay modes
▪ Serial interface controls chip functions
▪ Synchronous rectification for low power dissipation
▪ Internal UVLO and thermal-shutdown circuitry
▪ Crossover-current protection
Packages:
29319.31F
Package B, 24-pin DIP
with exposed tabs
DS(on)
STROBE
ENABLE
RANGE
CLOCK
PHASE
MODE
outputs (270 mΩ, typical)
DATA
OSC
SUPPLY
Not to scale
LOGIC
PROGRAMMABLE
PWM TIMER
V
CHARGE PUMP
DD
BANDGAP
C
V
REG
TSD
DD
Package LB, 24-pin SOIC
with internally fused pins
FIXED OFF
CONTROL LOGIC
BLANK
DECAY
SERIAL
FAULT DETECT
PORT
VOLTAGE &
UNDER-
Functional Block Diagram
DMOS Full-Bridge PWM Motor Driver
SLEEP
MODE
CHARGE
PUMP
Description
Designed for pulse width modulated (PWM) current control of
DC motors, the A3958 is capable of continuous output currents
to ±2 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.
PHASE and ENABLE input terminals are provided for use
in controlling the speed and direction of a DC motor with
externally applied PWM-control signals. The ENABLE input
can be programmed via the serial port to PWM the bridge in
fast or slow current decay. Internal synchronous rectification
control circuitry is provided to reduce power dissipation during
PWM operation.
Internal circuit protection includes thermal shutdown with
hysteresis, and crossover-current protection. Special power-up
sequencing is not required.
The A3958 is supplied in a choice of two power packages, a
24-pin plastic DIP with exposed thermal tabs (package suffix
‘B’), and a 24-pin SOIC with internally fused pins (package
suffix ‘LB’). In both cases, the power pins are at ground potential
and need no electrical isolation. Each package type is lead (Pb)
free, with 100% matte tin leadframe.
CURRENT
SENSE
CURRENT
DETECT
RANGE
ZERO
LOAD
SUPPLY
V
REFERENCE
BB
BUFFER &
DIVIDER
+
REGULATOR
BANDGAP
V
REF
OUT
OUT
SENSE
REG
A
B
R
S
Dwg. FP-048
C
S
V
REF
A3958