A5976 Datasheet, PDF (1/16 Pages) Allegro MicroSystems – Microstepping DMOS Driver with Translator

A5976
Microstepping DMOS Driver with Translator
FEATURES AND BENEFITS
• ±2.8 A, 40 V output rating
• Low R_DS(on) outputs, 0.22 Ω source, 0.15 Ω sink typical
• Automatic current decay mode detection/selection
• 3 to 5.5 V logic supply voltage range
• Mixed, fast, and slow current decay modes
• Fault output
• Mixed decay for both rising/falling step option
• Synchronous rectification for low power dissipation
• Internal UVLO and thermal shutdown circuitry
• Crossover-current protection
• Short-to-ground protection
• Short-to-VBB protection
• Shorted load protection
Package: 28-lead TSSOP (suffix LP) with
exposed thermal pad
Not to scale
DESCRIPTION
The A5976 is a complete microstepping motor driver with
built-in translator. It is designed to operate bipolar stepper
motors in full-, half-, quarter-, and sixteenth-step modes, with
output drive capability of 40 V and ±2.8 A. The A5976 includes
a fixed off-time current regulator that has the ability to operate in
slow-, fast-, or mixed-decay modes. This current-decay control
scheme results in reduced audible motor noise, increased step
accuracy, and reduced power dissipation.
The translator is the key to the easy implementation of the
A5976. Simply inputting one pulse on the STEP input drives the
motor one step (two logic inputs determine if it is a full-, half-,
quarter-, or sixteenth-step). There are no phase sequence tables,
high-frequency control lines, or complex interfaces to program.
The A5976 interface is an ideal fit for applications where a
complex microprocessor is unavailable or overburdened.
Internal synchronous rectification control circuitry is provided
to improve power dissipation during PWM operation. Internal
circuit protection includes thermal shutdown with hysteresis,
undervoltage lockout (UVLO), and crossover-current
protection. Special power-up sequencing is not required.
The A5976 is supplied in a thin (<1.2 mm) 28-pin TSSOP
with an exposed thermal pad (suffix LP). The package is lead
(Pb) free (suffix -T), with 100% matte-tin leadframe plating.
Logic
Supply
Microcontroller
or
Controller Logic
Typical Application
VDD
REF
PFD
FAULTn
STEP
DIR
RESETn
SLEEPn
ENABLEn
MS1
MS2
DECAY
A5976
RC1
RC2
VREG
CP1
CP2
VCP
VBB1
VBB2
OUT1A
OUT1B
SENSE1
SENSE2
OUT2A
OUT2B
GND
PGND
Load
Supply
100 µF
A5976-DS, Rev. 2