A4979
Microstepping Programmable Stepper Motor Driver
With Stall Detect and Short Circuit Protection
Functional Block Diagram
3.3V
VDD
REF
STEP
DIR
MS1
MS0
RESETn
ENABLE
SDI
SDO
SCK
STRn
DIAG
OSC
VREG
CP1 CP2
DAC REF
Oscillator
6-bit
DAC
SENSA
+-
Regulator
Charge
Pump
DMOS Full Bridge
PWM
Control
System
Control
and
Registers
Bridge
Control
Logic
Gate
Drive
DMOS Full Bridge
PWM
Control
REF
6-bit
DAC
+-
SENSB
VCP
VBB
VBBA
OAP
OAM
SENSA
VBB
VBBB
OBP
OBM
SENSB
Undervoltage, Cold Warning,
Hot Warning, Overtemperature
Short Detect, Open Load Detect
Stall Detect
AGND
PAD
PGND
Allegro MicroSystems, LLC
3
115 Northeast Cutoff
Worcester, Massachusetts 01615-0036 U.S.A.
1.508.853.5000; www.allegromicro.com