A4988SETTR-T

Microstepping Motor Driver

The A4988SETTR-T is a microstepping motor driver from Allegro MicroSystems. View the full A4988SETTR-T datasheet below including key specifications, electrical characteristics, absolute maximum ratings.

Official A4988SETTR-T datasheet (PDF) — the source this page was extracted from.

Manufacturer

Allegro MicroSystems

A4988SETTR-T Key Specifications

Parameter	Value
Output Current	±2A
Microstep Modes	Full, 1/2, 1/4, 1/8, 1/16
Package Dimensions	5mm x 5mm x 0.90mm
Communication Interface	Step/Direction, Microstep Select (MSx)
Output On Resistance Typ	320 mΩ
Load Supply Voltage Range	8V to 35V
Logic Supply Voltage Range	3V to 5.5V
Operating Temperature Range	-20°C to 85°C
Sleep Mode Current Consumption	10 µA (max)

A4988SETTR-T Overview

Part: A4988SETTR-T — Allegro MicroSystems

Type: DMOS Microstepping Bipolar Stepper Motor Driver

Description: Microstepping driver with built-in translator, 8–35 V motor supply, up to ±2 A output, and five step modes (full to 1/16), packaged in a 5 mm × 5 mm 28-contact QFN.

Operating Conditions:

Load supply voltage (VBB): 8–35 V (0–35 V during sleep mode)
Logic supply voltage (VDD): 3–5.5 V
Operating ambient temperature: -20 to 85 °C
Reference input voltage (VREF): 0–4 V

Absolute Maximum Ratings:

Max load supply voltage (VBB): 35 V
Max output current (IOUT): ±2 A
Motor output voltage: -2.0 to 37 V
Logic input voltage: -0.3 to 5.5 V
Max junction temperature: 150 °C
Storage temperature: -55 to 150 °C

Key Specs:

Output on-resistance (source or sink, IOUT = ±1.5 A): 320 mΩ typ, 430 mΩ max
Body diode forward voltage (IF = 1.5 A): 1.2 V max
Motor supply current IBB: 4 mA max (fPWM < 50 kHz); 10 μA max in sleep mode
Logic supply current IDD: 8 mA max (fPWM < 50 kHz); 10 μA max in sleep mode
Fixed off-time: 30 μs typ (OSC = VDD or GND)
Blank time: 1 μs typ
Crossover dead time: 475 ns typ (100–800 ns)
Overcurrent protection threshold: 2.1 A min
Thermal shutdown: 165 °C typ, 15 °C hysteresis
VDD UVLO: 2.8 V typ (rising), 90 mV hysteresis
Thermal resistance RθJA: 32 °C/W (four-layer PCB, JEDEC)

Features:

Low Rds(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 V and 5 V compatible logic supply
Thermal shutdown circuitry
Short-to-ground protection
Shorted load protection
Five selectable step modes: full, 1/2, 1/4, 1/8, 1/16

Applications:

Bipolar stepper motor drive where a complex microprocessor is unavailable or overburdened

Package:

28-contact QFN with exposed thermal pad, 5 mm × 5 mm × 0.90 mm (ET package), lead (Pb) free, 1500 pieces per 7-in. reel

A4988SETTR-T Features

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
Thermal shutdown circuitry
Short-to-ground protection
Shorted load protection
Five selectable step modes: full, 1 / 2 , 1 / 4 , 1 / 8 , and 1 / 16

A4988SETTR-T Electrical Characteristics

Characteristics	Symbol	Test Conditions	Min.	Typ. [2]	Max.	Units
OUTPUT DRIVERS
Load Supply Voltage Range	V BB	Operating	8	-	35	V
		During Sleep Mode	0	-	35	V
Logic Supply Voltage Range	V DD	Operating	3	-	5.5	V
Output On-Resistance	R ds(on)	Source driver, I OUT = -1.5 A	-	320	430	mΩ
		Sink driver, I OUT = 1.5 A	-	320	430	mΩ
Body Diode Forward Voltage	V	Source diode, I F = -1.5 A	-	-	1.2	V
	F	Sink diode, I F = 1.5 A	-	-	1.2	V
Motor Supply Current	I BB	f PWM < 50 kHz	-	-	4	mA
		Operating, outputs disabled	-	-	2	mA
		Sleep Mode	-	-	10	μA
Logic Supply Current	I DD	f PWM < 50 kHz	-	-	8	mA
Logic Supply Current		Outputs off	-	-	5	mA
Logic Supply Current		Sleep Mode	-	-	10	μA
CONTROL LOGIC
Logic Input Voltage	V IN(1)		V DD × 0.7	-	-	V
	V IN(0)		-	-	V DD × 0.3	V
Logic Input Current	I IN(1)	V IN = V DD × 0.7	-20	<1.0	20	μA
	I IN(0)	V IN = V DD × 0.3	-20	<1.0	20	μA
	R MS1	MS1 pin	-	100	-	kΩ
Microstep Select	R MS2	MS2 pin	-	50	-	kΩ
	R MS3	MS3 pin	-	100	-	kΩ
Logic Input Hysteresis	V HYS(IN)	As a %of V DD	5	11	19	%
Blank Time	t BLANK		0.7	1	1.3	μs
Fixed Off-Time		OSC = VDD or GND	20	30	40	μs
	t OFF	R OSC = 25 kΩ	23	30	37	μs
Reference Input Voltage Range	V REF		0	-	4	V
Reference Input Current	I REF		-3	0	3	μA
Current Trip-Level Error [3]		V REF = 2 V, %I TripMAX = 38.27%	-	-	±15	%
	err I	V REF = 2 V, %I TripMAX = 70.71%	-	-	±5	%
		V REF = 2 V, %I TripMAX = 100.00%	-	-	±5	%
Crossover Dead Time	t DT		100	475	800	ns
PROTECTION
Overcurrent Protection Threshold [4]	I OCPST		2.1	-	-	A
Thermal Shutdown Temperature	T TSD		-	165	-	°C
Thermal Shutdown Hysteresis	T TSDHYS		-	15	-	°C
VDD Undervoltage Lockout	V DDUVLO	V DD rising	2.7	2.8	2.9	V
VDD Undervoltage Hysteresis	V DDUVLOHYS		-	90	-	mV

A4988SETTR-T Absolute Maximum Ratings

Characteristic	Symbol	Rating	Units
Load Supply Voltage	V BB	35	V
Output Current	I OUT	±2	A
Logic Input Voltage	V IN	-0.3 to 5.5	V
Logic Supply Voltage	V DD	-0.3 to 5.5	V
Motor Outputs Voltage		-2.0 to 37	V
Sense Voltage	V SENSE	-0.5 to 0.5	V
Reference Voltage	V REF	5.5	V
Operating Ambient Temperature	T A	-20 to 85	°C
Maximum Junction	T J (max)	150	°C
Storage Temperature	T stg	-55 to 150	°C

The A4988 is supplied in a surface-mount QFN package (ET), 5 mm × 5 mm, with a nominal overall package height of 0.90 mm and an exposed pad for enhanced thermal dissipation. It is lead (Pb) free (suffix -T), with 100% matte-tin-plated leadframes.

A4988SETTR-T Thermal Information

Characteristic	Symbol	Test Conditions*	Value	Units
Package Thermal Resistance	R θJA	Four-layer PCB, based on JEDEC standard	32	°C/W

Figure 1: Logic Interface Timing Diagram

Time Duration	Symbol	Typ.	Unit
STEP minimum, HIGH pulse width	t A	1	μs
STEP minimum, LOW pulse width	t B	1	μs
Setup time, input change to STEP	t C	200	ns
Hold time, input change to STEP	t D	200	ns

Table 1: Microstepping Resolution Truth Table

MS1	MS2	MS3	Microstep Resolution	Excitation Mode
L	L	L	Full Step	2 Phase
H	L	L	Half Step	1-2 Phase
L	H	L	Quarter Step	W1-2 Phase
H	H	L	Eighth Step	2W1-2 Phase
H	H	H	Sixteenth Step	4W1-2 Phase

Table 1: Microstepping Resolution Truth Table

A4988SETTR-T Typical Application

Variants on the same datasheet

These parts have exact links to the same datasheet. They are candidates to compare, not verified drop-in replacements; check package, pinout and electrical limits.

Part Number	Manufacturer	Package
A4988	Allegro MicroSystems	QFN-28 5x5mm

More datasheets

All Allegro MicroSystems datasheets (14)

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