A3979SLP-T Equivalent & Substitute Parts

Part Overview

The A3979SLP-T is a bipolar stepper motor driver IC manufactured by Allegro MicroSystems, designed for fully integrated motor control and power stage applications. This device operates across a 3V to 5.5V supply voltage range and supports multiple step resolutions including 1, 1/2, 1/4, and 1/16 stepping modes. The A3979SLP-T is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements.

Substiute Parts

A3979SLP-T

Allegro MicroSystemsIn Stock: 744A3979SLP-T Datasheet

Current PartRFQ

A3979SLPTR-T

Allegro MicroSystemsIn Stock: 25749A3979SLPTR-T Datasheet

MFR RecommendedRFQ

DRV8811PWP

Texas InstrumentsIn Stock: 3807DRV8811PWP Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the A3979SLP-T is determined by the following critical parameters:

Motor driver type and control architecture (bipolar stepper motor driver with fully integrated control and power stage)

Output configuration (half bridge with 4 outputs)

Supply voltage range (3V to 5.5V minimum compatibility)

Load voltage range (minimum 8V support)

Output current capability (minimum 2.5A)

Step resolution support (minimum 1, 1/2, 1/4 stepping)

Package compatibility (28-pin TSSOP form factor with exposed pad)

Surface mount technology

Two substitute parts meet these criteria: the A3979SLPTR-T (Allegro MicroSystems, active product status) and the DRV8811PWP (Texas Instruments, active product status). Both devices maintain electrical and mechanical compatibility with the A3979SLP-T within the specified parameter ranges.

Parameter Comparison

Engineering Selection Recommendations

The A3979SLPTR-T is the primary substitute for the obsolete A3979SLP-T. Both parts are manufactured by Allegro MicroSystems and share identical electrical specifications, including 2.5A output current, 3V to 5.5V supply voltage, and full step resolution support (1, 1/2, 1/4, 1/16). The A3979SLPTR-T maintains active product status and is available in higher inventory quantities. Packaging and thermal characteristics are equivalent. The primary difference is moisture sensitivity level (MSL 2 versus MSL 1), which affects storage and handling requirements but does not impact electrical performance.

The DRV8811PWP from Texas Instruments is an alternative substitute that maintains compatibility across core functional parameters. This device supports the same supply voltage range (3V to 5.5V) and output configuration (half bridge, 4 outputs). Key differences include reduced output current capability (1.9A versus 2.5A), reduced step resolution support (1, 1/2, 1/4, 1/8 versus 1, 1/2, 1/4, 1/16), and different package designation (28-PowerTSSOP versus 28-TSSOP). The DRV8811PWP offers extended operating temperature range (-40°C to 150°C) and higher load voltage support (8V to 38V). Selection of the DRV8811PWP requires confirmation that application requirements do not exceed 1.9A output current and do not require 1/16 step resolution.

Both substitute parts carry ROHS3 compliance and are suitable for new designs requiring bipolar stepper motor driver functionality.

Frequently Asked Questions (FAQ)

Q: Can the A3979SLPTR-T directly replace the A3979SLP-T in existing designs?

A: Yes. The A3979SLPTR-T is electrically and mechanically equivalent to the A3979SLP-T. Both devices share identical supply voltage (3V to 5.5V), output current (2.5A), load voltage (8V to 35V), step resolution (1, 1/2, 1/4, 1/16), and package form factor (28-TSSOP with exposed pad). The primary difference is moisture sensitivity level, which affects storage conditions but not circuit performance.

Q: What are the limitations of using the DRV8811PWP as a substitute?

A: The DRV8811PWP has two parameter restrictions compared to the A3979SLP-T. Output current is reduced to 1.9A (versus 2.5A), and step resolution support is limited to 1, 1/2, 1/4, and 1/8 (versus 1, 1/2, 1/4, 1/16). Applications requiring 1/16 step resolution or output currents above 1.9A cannot use the DRV8811PWP. The package designation differs (28-PowerTSSOP versus 28-TSSOP), requiring PCB layout verification.

Q: Are all substitute parts RoHS compliant?

A: Yes. The A3979SLPTR-T and DRV8811PWP are both ROHS3 compliant, matching the compliance status of the A3979SLP-T.

Q: What is the difference between 28-TSSOP and 28-PowerTSSOP packaging?

A: Both are 28-pin thin shrink small outline packages with 0.173" width and 4.40mm body width. The PowerTSSOP variant (used by the DRV8811PWP) is optimized for higher power dissipation applications. PCB footprint compatibility must be verified before substitution, as pin layouts may differ.

Q: How do moisture sensitivity levels affect part selection?

A: Moisture sensitivity level (MSL) determines storage and handling requirements. The A3979SLP-T (MSL 1) has unlimited shelf life. The A3979SLPTR-T (MSL 2) requires storage within 1 year of manufacture. The DRV8811PWP (MSL 3) requires storage within 168 hours of manufacture. Higher MSL ratings require more stringent moisture control during storage and assembly processes.