A3940KLPTR Motor Driver IC - Equivalent & Substitute Parts

Part Overview

The A3940KLPTR is a motor driver IC from Allegro MicroSystems designed for brushed DC motor control applications. It functions as a pre-driver with half-bridge output configuration, supporting parallel interface control with power MOSFET technology. The device operates across a 7V to 40V supply voltage range and is rated for automotive-grade applications with an operating temperature range of -40°C to 135°C.

The A3940KLPTR is classified as obsolete. Identifying suitable substitute parts is necessary to maintain design continuity, ensure component availability, and support ongoing production requirements for systems utilizing this motor driver architecture.

Substiute Parts

A3940KLPTR

Allegro MicroSystemsIn Stock: 1080A3940KLPTR Datasheet

Current PartRFQ

A3941KLPTR-T

Allegro MicroSystemsIn Stock: 25535A3941KLPTR-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the A3940KLPTR is determined by the following critical parameters:

Mechanical Compatibility:

• Package type: 28-TSSOP with exposed pad (identical footprint required)
• Mounting type: Surface mount
• Physical dimensions: 0.173" width, 4.40mm width specification

Functional Compatibility:

• Motor driver application for brushed DC motors
• Pre-driver half-bridge output configuration (2 channels)
• Power MOSFET technology
• Automotive-grade qualification

Electrical Operating Range:

• Supply voltage overlap within specified ranges
• Operating temperature range coverage
• Interface compatibility (parallel or PWM control)

The A3941KLPTR-T qualifies as a substitute based on identical package geometry, matching functional architecture, automotive-grade certification, and overlapping electrical operating parameters. The substitute extends the supply voltage range to 5.5V–50V and improves the maximum operating temperature to 150°C, providing enhanced capability within the same physical footprint.

Parameter Comparison

Engineering Selection Recommendations

Product Status Consideration: The A3940KLPTR is obsolete, making the A3941KLPTR-T the appropriate selection for new designs and ongoing production support. The substitute maintains active product status with established supply chain availability.

Compliance and Certification: The A3941KLPTR-T provides ROHS3 compliance, addressing regulatory requirements that the non-compliant A3940KLPTR does not meet. Both devices maintain automotive-grade qualification and REACH unaffected status, supporting automotive application requirements.

Electrical Performance: The A3941KLPTR-T extends the supply voltage operating range from 7V–40V to 5.5V–50V and increases the maximum operating temperature from 135°C to 150°C. These enhancements provide greater design flexibility and thermal margin without compromising the original 7V–40V operating window.

Interface Compatibility: The A3940KLPTR uses parallel interface control, while the A3941KLPTR-T implements PWM interface control. Design integration requires verification that the control architecture supports PWM signaling or that interface adaptation is implemented.

Package and Mechanical Compatibility: Both devices use identical 28-TSSOP packaging with exposed pad configuration, ensuring direct footprint compatibility on existing PCB layouts without redesign.

Frequently Asked Questions (FAQ)

Q: Can the A3941KLPTR-T be used as a direct replacement for the A3940KLPTR?

A: The A3941KLPTR-T is mechanically and functionally compatible, sharing the same 28-TSSOP package footprint and half-bridge pre-driver architecture. However, the interface differs: the A3940KLPTR uses parallel control while the A3941KLPTR-T uses PWM control. Verify that your control circuit supports PWM signaling before substitution.

Q: What are the key differences between these two parts?

A: The primary differences are: (1) Product status—A3940KLPTR is obsolete; A3941KLPTR-T is active; (2) Interface—parallel versus PWM; (3) Supply voltage range—7V–40V versus 5.5V–50V; (4) Maximum operating temperature—135°C versus 150°C; (5) RoHS compliance—non-compliant versus ROHS3 compliant.

Q: Are the packages identical?

A: Yes. Both devices use 28-TSSOP packaging with exposed pad (28-TSSOP-EP), with identical physical dimensions of 0.173" width and 4.40mm width specification. PCB footprints are directly compatible.

Q: Does the A3941KLPTR-T support the same motor control functions?

A: Yes. Both devices provide commutation and direction management functions for brushed DC motors with identical pre-driver half-bridge output configuration (2 channels) and power MOSFET technology.

Q: What is the impact of the interface change from parallel to PWM?

A: The control signal format differs. Parallel interface uses discrete logic signals for each control function, while PWM interface uses pulse-width modulation. Your control circuit must be capable of generating PWM signals, or interface adaptation circuitry must be implemented.

Q: Is the A3941KLPTR-T suitable for automotive applications?

A: Yes. The A3941KLPTR-T maintains automotive-grade qualification, identical to the A3940KLPTR, and adds ROHS3 compliance for enhanced regulatory alignment.

Q: What is the moisture sensitivity difference?

A: The A3940KLPTR has MSL 1 (unlimited shelf life), while the A3941KLPTR-T has MSL 2 (1-year shelf life). MSL 2 requires controlled storage conditions and has a defined floor life after moisture exposure.