A4940KLPTR-T Equivalent & Substitute Parts

Part Overview

The A4940KLPTR-T is a brushed DC motor driver IC manufactured by Allegro MicroSystems, designed for power management applications requiring motor commutation and direction control. This device operates across a 5.5V to 50V supply range and is housed in a 24-TSSOP package with exposed pad. The part is classified as Obsolete, making identification of functionally equivalent alternatives essential for ongoing production and design continuity.

Substiute Parts

A4940KLPTR-T

Allegro MicroSystemsIn Stock: 18559A4940KLPTR-T Datasheet

Current PartRFQ

A3941KLPTR-T

Allegro MicroSystemsIn Stock: 25535A3941KLPTR-T Datasheet

MFR RecommendedRFQ

A5947KLPTR-T

Allegro MicroSystemsIn Stock: 5868A5947KLPTR-T Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the A4940KLPTR-T is determined by the following critical parameters:

• Motor Type: Brushed DC motor control capability
• Output Configuration: Pre-Driver Half Bridge topology (2-channel)
• Voltage Supply Range: 5.5V ~ 50V operation
• Interface Type: Control signal methodology (On/Off, PWM, or Analog)
• Package Compatibility: Surface mount TSSOP with exposed pad
• Automotive Grade: AEC-Q100 qualification or equivalent automotive compliance
• RoHS Compliance: ROHS3 Compliant status

Two substitute parts meet the core functional requirements for brushed DC motor control with half-bridge pre-driver output and automotive-grade qualification. However, each introduces specific trade-offs in interface capability and package pin count.

Parameter Comparison

Engineering Selection Recommendations

A3941KLPTR-T is the primary recommended substitute for the A4940KLPTR-T. Both devices maintain identical brushed DC motor control functionality with half-bridge pre-driver output, matching voltage supply range (5.5V ~ 50V), and automotive-grade qualification. The A3941KLPTR-T is currently in Active product status, ensuring long-term availability. The primary difference is the interface upgrade from On/Off to PWM control and a package increase from 24-pin to 28-pin TSSOP. This substitution requires PCB layout modification to accommodate the additional pins but provides enhanced control flexibility.

A5947KLPTR-T is not recommended as a direct substitute. Although it shares Allegro MicroSystems manufacturing and automotive-grade qualification, it is designed for brushless DC (BLDC) motor applications rather than brushed DC control. The device is classified as Not For New Designs, indicating limited future availability. Additionally, the operating temperature range is reduced to -40°C ~ 125°C (TA), which is below the A4940KLPTR-T specification. This part is suitable only if application requirements can be modified to accommodate BLDC motor control.

Frequently Asked Questions (FAQ)

Q: Can the A3941KLPTR-T directly replace the A4940KLPTR-T without circuit modification?

A: The A3941KLPTR-T requires PCB layout changes due to the package increase from 24-TSSOP to 28-TSSOP. Pin assignments differ, and the additional pins must be properly routed. Schematic review is necessary to confirm interface compatibility between On/Off (A4940KLPTR-T) and PWM (A3941KLPTR-T) control signals.

Q: What is the impact of the interface change from On/Off to PWM?

A: The A3941KLPTR-T PWM interface provides variable speed control capability, whereas the A4940KLPTR-T On/Off interface provides only binary motor control. If the application requires fixed-speed operation, PWM control can be configured to operate at fixed duty cycle. If variable speed is required, PWM control offers superior performance.

Q: Why is the A5947KLPTR-T not suitable as a substitute?

A: The A5947KLPTR-T is designed for brushless DC (BLDC) motor control, which requires three-phase commutation and field-oriented control (FOC). The A4940KLPTR-T is designed for brushed DC motors, which require two-phase half-bridge commutation. These are fundamentally different motor types and control architectures. Additionally, the A5947KLPTR-T is classified as Not For New Designs.

Q: Are all three parts automotive-grade qualified?

A: Yes. The A4940KLPTR-T and A3941KLPTR-T are automotive-grade. The A5947KLPTR-T carries AEC-Q100 qualification. All three meet automotive reliability standards.

Q: What are the package footprint differences?

A: The A4940KLPTR-T uses 24-TSSOP, the A3941KLPTR-T uses 28-TSSOP, and the A5947KLPTR-T uses 20-TSSOP. All maintain the same 0.173" width and 4.40mm body width. Pin pitch and exposed pad dimensions differ. PCB layout must be redesigned for any package change.