A3959SLPTR Datasheet, PDF (1/11 Pages) Allegro MicroSystems – DMOS Full-Bridge PWM Motor Driver

A3959
DMOS Full-Bridge PWM Motor Driver
Features and Benefits
▪ ±3 A, 50 V Output Rating
▪ Low r_DS(on) Outputs (270 mΩ, Typical)
▪ Mixed, Fast, and Slow Current-Decay Modes
▪ Synchronous Rectification for Low Power Dissipation
▪ Internal UVLO and Thermal-Shutdown Circuitry
▪ Crossover-Current Protection
▪ Internal Oscillator for Digital PWM Timing
Packages:
Package B, 24-pin DIP
with exposed tabs
Package LB, 24-pin SOIC
with internally fused pins
Package LP, 28-pin TSSOP
with exposed thermal pad
Not to scale
Description
Designed for pulse width modulated (PWM) current control of
DC motors, the A3959 is capable of output currents to ±3 A and
operating voltages to 50 V. Internal fixed off-time PWM current-
control timing circuitry can be adjusted via control inputs 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. Internal synchronous
rectification control circuitry is provided to reduce power
dissipation during PWM operation.
Internal circuit protection includes thermal shutdown with
hysteresis, undervoltage monitoring of supply and charge
pump, and crossover-current protection. Special power-up
sequencing is not required.
The A3959 provides a choice of three power packages, a 24-pin
DIP with batwing tabs (package suffix ‘B’), a 24-lead SOIC
with four internally-fused pins (package suffix ‘LB’), and a
thin (<1.2 mm) 28-pin TSSOP with an exposed thermal pad
(suffix ‘LP’). In all cases, the power pins and tabs are at ground
potential and need no electrical isolation. Each package is lead
(Pb) free, with 100% matte tin leadframes.
Functional Block Diagram
VDD
LOGIC
SUPPLY
VBB
+
LOAD
SUPPLY
TO VDD
CHARGE PUMP
BANDGAP
VDD
CREG
TSD
UNDER-
VOLTAGE &
FAULT DETECT
CHARGE
PUMP
BANDGAP
REGULATOR
VREG
SLEEP
EXT MODE
PHASE
ENABLE
TO VDD
BLANK
PFD1
PFD2
ROSC
29319.37K
CONTROL LOGIC
PWM
TIMER
OSC
ZERO
CURRENT
DETECT
CURRENT
SENSE
REFERENCE
BUFFER &
w10
OUTA
OUTB
SENSE
CS
RS
REF
VREF
Dwg. FP-048-2A