A3992
DMOS Dual Full-Bridge Microstepping PWM Motor Driver
Features and Benefits
Description
▪ ±1.5 A, 50 V continuous output rating
▪ Low RDS(on) DMOS output drivers
Designed for pulse width modulated (PWM) current control of
bipolar microstepped stepper motors, the A3992 is capable of
continuous output currents to ±1.5 A and operating voltages to
50 V. Internalfixedoff-timePWMcurrentcontroltimingcircuitry
can be programmed via the serial interface to operate in slow, fast,
or mixed decay modes.
▪ Short-to-ground protection
▪ Shorted load protection
▪ Optimized microstepping via six bit linear DACs
▪ Programmable mixed, fast, and slow current decay modes
▪ 4 MHz internal oscillator for digital timing
▪ Serial interface controls chip functions
▪ Synchronous rectification for low power dissipation
▪ Internal UVLO and thermal shutdown circuitry
▪ Crossover-current protection
The desired load current level is set via the serial port with two
six bit linear DACs in conjunction with a reference voltage. The
six bits of control allow maximum flexibility in torque control for
a variety of step methods, from microstepping to full step drive.
Load current is set in 1.56% increments of the maximum value.
▪ Inputs compatible with 5 or 3.3 V control signals
▪ Sleep and Idle modes
Synchronousrectificationcircuitryallowstheloadcurrenttoflow
through the low RDS(on) of the DMOS output driver during current
decay. This feature eliminates the need for external clamp diodes
in most applications, saving cost and external component count,
while minimizing power dissipation.
Packages
24 pin batwing DIP (suffix B) and 24 pin TSSOP with
exposed thermal pad (suffix LP)
Internal circuit protection includes short-to-ground, shorted load,
thermalshutdownwithhysteresis,andcrossovercurrentprotection.
Special power up sequencing is not required.
TheA3992 is supplied in a thin profile (1.2 mm maximum height)
24 pin TSSOP (suffix LP) with exposed thermal pad and a 24 pin
plasticDIPwithdualcopper batwingtabs(suffixB).Theexposed
thermalpadontheLPisatgroundpotentialandneedsnoelectrical
isolation. Both packages are lead (Pb) free with 100% matte tin
leadframe plating.
LP package approximate scale
Typical Application
0.22 μF
VREG
VDD
0.22 μF
CP1
CP2
VCP
0.22 μF
10 μF
5 kΩ
VBB1
VBB2
ROSC
Microcontroller or
Controller Logic
A3992
100 μF
0.1 μF
CLOCK
DATA
OUT1A
OUT1B
SENSE1
STROBE
REF
OUT2A
OUT2B
SLEEP
SENSE2
0.1 μF
3992DS