A3918 Datasheet, PDF (1/8 Pages) Allegro MicroSystems – Low Voltage DC Motor Driver

A3918
Low Voltage DC Motor Driver
Features and Benefits
▪ 2.5 to 9 V operation
▪ Internal PWM current control
▪ Synchronous rectification for reduced power dissipation
▪ Peak current output flag
▪ Undervoltage lockout
▪ Low R_DS(on) outputs
▪ Small package
▪ Brake mode for DC motor
▪ Sleep function
▪ Crossover-current protection
▪ Thermal shutdown
Package: 16-contact QFN (suffix ES)
3 × 3 mm
0.75 mm overall height
Approximate size
Description
Designed for pulse width modulated (PWM) control of a low
voltage DC motor, the A3918 is capable of output currents up
to 1.5 A and operating voltages from 2.5 to 9 V.
The A3918 has an internal fixed off-time PWM timer that
sets a peak current based on the selection of a current sense
resistor. An overcurrent output flag is provided that notifies
the user when the current in the motor winding reaches the
peak current determined by the sense resistor. The fault output
does not affect driver operation.
TheA3918 is provided in a 16-contact, 3 mm × 3 mm, 0.75 mm
nominal overall height QFN, with exposed pad for enhanced
thermal dissipation. It is lead (Pb) free, with 100% matte tin
leadframe plating.
Applications include the following:
▪ Digital still cameras (DSC)
▪ Cell phone cameras
▪ USB powered devices
▪ Battery powered devices
A3918-DS
Functional Block Diagram
0.1 μF
0.1 μF
0.1 μF
+5 V
10 μF
10 V
VBB
SLEEP
FL
IN1
IN2
Regulator
Sense
Charge
Pump
PWM Latch
and
Blanking
Comparator
Bridge
VCP
VBB
Control Logic
GND
PAD
GND
Sense
GND
OUTA
OUTB
SENSE
RSENSE