A3977KLP-T Equivalent & Substitute Parts

Part Overview

The A3977KLP-T is a bipolar stepper motor driver IC manufactured by Allegro MicroSystems, designed for fully integrated motor control and power stage applications. This device integrates DMOS logic technology with half-bridge output configuration, supporting step resolutions from full step to 1/8 microstepping. The A3977KLP-T is classified as obsolete, making identification of active equivalent parts essential for new designs and production continuity.

Substiute Parts

A3977KLP-T

Allegro MicroSystemsIn Stock: 777A3977KLP-T Datasheet

Current PartRFQ

A3977SLPTR-T

Allegro MicroSystemsIn Stock: 11238A3977SLPTR-T Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the A3977KLP-T is determined by strict equivalence across the following critical parameters:

• Base product number (A3977 series)
• Motor driver function and output configuration (Bipolar, Half Bridge 4)
• Electrical specifications (2.5A output current, 3V-5.5V supply, 8V-35V load voltage)
• Package type (28-TSSOP-EP)
• Technology platform (DMOS Logic)
• Step resolution capability (1, 1/2, 1/4, 1/8)

The A3977SLPTR-T meets all substitution criteria as a direct functional equivalent within the A3977 product family. Differences in product status, operating temperature range, and moisture sensitivity level do not affect electrical or mechanical compatibility.

Parameter Comparison

Engineering Selection Recommendations

The A3977SLPTR-T is the direct substitute for the obsolete A3977KLP-T. Both parts maintain identical electrical and mechanical specifications across all critical parameters including output current, supply voltage, load voltage, package configuration, and step resolution capabilities.

The A3977SLPTR-T carries active product status with established supply chain availability (11,200 pcs in stock versus 678 pcs for the obsolete variant). Both parts maintain ROHS3 compliance and REACH unaffected status, satisfying regulatory requirements for new designs.

The operating temperature range of the A3977SLPTR-T (-20°C to 150°C) is narrower than the A3977KLP-T (-40°C to 150°C) at the lower bound. Applications requiring operation below -20°C junction temperature must evaluate this specification against system requirements. The moisture sensitivity level difference (MSL 1 versus MSL 2) reflects packaging handling requirements but does not affect functional performance.

Frequently Asked Questions (FAQ)

Q: Can the A3977SLPTR-T directly replace the A3977KLP-T in existing designs?

A: Yes. Both parts share identical electrical specifications, output configuration, package type, and step resolution capabilities. No circuit modifications are required for substitution.

Q: What is the significance of the product status difference?

A: The A3977KLP-T is classified as obsolete, indicating discontinued manufacturing and limited inventory availability. The A3977SLPTR-T is active, ensuring long-term supply chain support and production continuity for new designs.

Q: Are there differences in operating temperature ranges that affect compatibility?

A: The A3977SLPTR-T operates from -20°C to 150°C junction temperature, compared to -40°C to 150°C for the A3977KLP-T. Applications requiring operation below -20°C must confirm compatibility with system thermal requirements.

Q: Do the moisture sensitivity level differences impact board assembly or storage?

A: The A3977SLPTR-T has MSL 2 (1 year floor life) versus MSL 1 (unlimited) for the A3977KLP-T. This affects moisture-controlled storage and handling procedures during manufacturing but does not impact electrical performance or long-term reliability after assembly.

Q: Are both parts compliant with current regulatory standards?

A: Yes. Both the A3977KLP-T and A3977SLPTR-T are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Q: Is the 28-TSSOP package identical between both parts?

A: Yes. Both parts use the 28-TSSOP (0.173", 4.40mm Width) Exposed Pad package with identical pinout and mechanical dimensions, ensuring direct PCB compatibility.