A3940KLP Equivalent & Substitute Parts

Part Overview

The A3940KLP is a motor driver IC from Allegro MicroSystems designed for brushed DC motor control applications. It integrates power MOSFET technology with commutation and direction management functions in a 28-TSSOP package with exposed pad. 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 A3940KLP is classified as obsolete. Identifying suitable substitute parts is necessary to maintain design continuity, ensure component availability, and support long-term production requirements for systems currently using this motor driver.

Substiute Parts

A3940KLP

Allegro MicroSystemsIn Stock: 2299A3940KLP Datasheet

Current PartRFQ

A3941KLPTR-T

Allegro MicroSystemsIn Stock: 25535A3941KLPTR-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the A3940KLP is determined by the following critical parameters:

• Package Compatibility: Both main and substitute parts must use the 28-TSSOP (0.173", 4.40mm Width) Exposed Pad package to ensure PCB layout and thermal management compatibility.
• Motor Control Function: The substitute must provide brushed DC motor control with commutation and direction management capabilities.
• Output Configuration: Half-bridge pre-driver topology with two output stages must be maintained.
• Technology Platform: Power MOSFET-based architecture is required.
• Voltage Supply Range: The substitute supply voltage range must encompass or exceed the original 7V to 40V specification to support existing system designs.
• Operating Temperature Range: The substitute must support the automotive temperature range of -40°C to 135°C minimum.
• Automotive Grade: Automotive-grade qualification is required for equivalent substitution.

The A3941KLPTR-T meets all substitution criteria and is classified as the manufacturer-recommended substitute.

Parameter Comparison

Engineering Selection Recommendations

The A3941KLPTR-T is the manufacturer-recommended substitute for the obsolete A3940KLP. Selection of this substitute is supported by the following engineering factors:

Product Availability and Support: The A3941KLPTR-T is classified as active product status with 25,510 units in stock, ensuring reliable long-term availability compared to the obsolete A3940KLP with limited remaining inventory.

Regulatory Compliance: The A3941KLPTR-T achieves ROHS3 compliance, meeting current environmental and regulatory requirements. The original A3940KLP is RoHS non-compliant, making the substitute necessary for new designs and regulatory adherence.

Electrical Performance: The A3941KLPTR-T supply voltage range of 5.5V to 50V encompasses the original 7V to 40V specification, providing backward compatibility with existing system designs. The extended upper temperature rating of -40°C to 150°C exceeds the original -40°C to 135°C specification, supporting broader thermal operating conditions.

Package and Pinout Compatibility: Both devices use identical 28-TSSOP packaging with exposed pad, ensuring direct PCB layout compatibility and thermal management equivalence.

Interface Consideration: The A3940KLP uses parallel interface control, while the A3941KLPTR-T uses PWM interface control. System designs must verify that the control signal architecture can accommodate PWM-based commutation and direction management before implementation.

Frequently Asked Questions (FAQ)

Q: Can the A3941KLPTR-T be used as a direct drop-in replacement for the A3940KLP?

A: The A3941KLPTR-T is pin-compatible and package-compatible with the A3940KLP, enabling direct PCB placement. However, the interface difference (parallel vs. PWM) requires verification that the system control circuitry can generate PWM signals for motor commutation and direction control. If the original design uses parallel control signals, firmware or control logic modifications may be necessary.

Q: What is the key difference between the A3940KLP and A3941KLPTR-T?

A: The primary differences are: (1) Interface type—A3940KLP uses parallel control while A3941KLPTR-T uses PWM control; (2) Supply voltage range—A3941KLPTR-T extends from 5.5V to 50V versus 7V to 40V; (3) Operating temperature—A3941KLPTR-T supports up to 150°C versus 135°C; (4) Product status—A3941KLPTR-T is active with full manufacturer support while A3940KLP is obsolete; (5) Regulatory compliance—A3941KLPTR-T is ROHS3 compliant.

Q: Are there any thermal or power dissipation differences between these devices?

A: Both devices use identical power MOSFET technology in the same 28-TSSOP package with exposed pad. Thermal performance and power dissipation characteristics are equivalent. The exposed pad design in both packages provides identical thermal management capability for PCB integration.

Q: What packaging options are available for the A3941KLPTR-T?

A: The A3941KLPTR-T is supplied in Cut Tape (CT) and Digi-Reel packaging formats. The device maintains the same 28-TSSOP (0.173", 4.40mm Width) Exposed Pad package specification as the original A3940KLP.

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

A: Yes. The A3941KLPTR-T carries automotive-grade qualification identical to the A3940KLP, meeting automotive industry standards and temperature requirements. The device is suitable for automotive motor control applications requiring brushed DC motor commutation and direction management.

Q: What is the moisture sensitivity level (MSL) for the A3941KLPTR-T?

A: The A3941KLPTR-T has an MSL rating of 2 (1 Year), indicating a one-year floor life from the date of manufacture under controlled storage conditions. This is more stringent than the A3940KLP (MSL 1, Unlimited), requiring adherence to proper storage and handling protocols.