A4983 Datasheet, PDF (1/16 Pages) Allegro MicroSystems – DMOS Microstepping Driver with Translator

A4983
DMOS Microstepping Driver with Translator
Features and Benefits
▪ Low R_DS(ON) outputs
▪ Automatic current decay mode detection/selection
▪ Mixed and Slow current decay modes
▪ Synchronous rectification for low power dissipation
▪ Internal UVLO
▪ Crossover-current protection
▪ 3.3 and 5 V compatible logic supply
▪ Very thin profile QFN package
▪ Thermal shutdown circuitry
Package: 28-pin QFN (suffix ET)
Description
The A4983 is a complete microstepping motor driver with
built-in translator for easy operation. It is designed to operate
bipolar stepper motors in full-, half-, quarter-, eighth, and
sixteenth-step modes, with an output drive capacity of up to
35 V and ±2 A. The A4983 includes a fixed off-time current
regulator which has the ability to operate in Slow or Mixed
decay modes.
The translator is the key to the easy implementation of the
A4983. Simply inputting one pulse on the STEP input drives
the motor one microstep. There are no phase sequence tables,
high frequency control lines, or complex interfaces to program.
The A4983 interface is an ideal fit for applications where a
complex microprocessor is unavailable or is overburdened.
The chopping control in the A4983 automatically selects the
current decay mode (Slow or Mixed). When a signal occurs at
the STEP input pin, the A4983 determines if that step results
in a higher or lower current in each of the motor phases. If
the change is to a higher current, then the decay mode is set
to Slow decay. If the change is to a lower current, then the
current decay is set to Mixed (set initially to a fast decay for
a period amounting to 31.25% of the fixed off-time, then to a
Approximate size
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Typical Application Diagram
V_DD
Microcontroller or
Controller Logic
0.22 μF
0.1 μF
0.1 μF
VREG VCP CP1 CP2 _VBB
V_BB
VDD
VBB
OUT1A
MS1
MS2
OUT1B
MS3
A4983
RS1
SLEEP
STEP
DIR
RESET
ENABLE
OUT2A
OUT2B
RS2
REF
ROSC
4983DS