LB1945H-MPB-E Equivalent & Substitute Parts

Part Overview

The LB1945H-MPB-E is a bipolar motor driver IC manufactured by onsemi, designed for fully integrated control and power stage applications in stepper motor systems. This device operates within a 4.75V to 5.25V supply voltage range and delivers 800mA output current across four half-bridge configurations. The product is classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

LB1945H-MPB-E

onsemiIn Stock: 1005LB1945H-MPB-E Datasheet

Current PartRFQ

A3966SLBTR-T

Allegro MicroSystemsIn Stock: 18503A3966SLBTR-T Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the LB1945H-MPB-E is determined by the following critical parameters:

• Motor Driver Type: Bipolar stepper motor driver with fully integrated control and power stage
• Output Configuration: Four half-bridge outputs for bipolar motor phase control
• Interface Type: Parallel control interface
• Supply Voltage Range: Minimum 4.75V compatibility required
• Output Current Capability: Minimum 650mA acceptable for reduced-current applications
• Load Voltage Range: Overlap within 10V ~ 28V operating window
• Mounting Technology: Surface mount packages only
• Thermal Operating Range: Minimum -20°C lower bound; upper bound flexibility acceptable

The A3966SLBTR-T qualifies as a functional substitute based on matching motor driver topology, output configuration, interface protocol, and overlapping electrical specifications within the defined parameter constraints.

Parameter Comparison

Engineering Selection Recommendations

The A3966SLBTR-T is an active, functionally equivalent substitute for the obsolete LB1945H-MPB-E. Selection of this alternative is based on the following engineering criteria:

Product Status: The LB1945H-MPB-E is obsolete with no ongoing manufacturing support. The A3966SLBTR-T is actively produced by Allegro MicroSystems, ensuring long-term availability and supply chain continuity.

Functional Equivalence: Both devices implement identical bipolar stepper motor driver architecture with four half-bridge outputs, parallel control interface, and fully integrated control and power stages.

Electrical Compatibility: The A3966SLBTR-T operates within the LB1945H-MPB-E supply voltage range (4.75V ~ 5.25V overlap) and supports the required load voltage window (10V ~ 28V). Output current rating of 650mA is suitable for applications not requiring the full 800mA capability of the original device.

Compliance and Certifications: Both devices carry identical Moisture Sensitivity Level (MSL) ratings of 3 (168 Hours), REACH Unaffected status, and EAR99 ECCN classification, ensuring equivalent handling, storage, and regulatory compliance requirements.

Design Consideration: Package footprint differs between devices (28-SOP versus 16-PowerSOIC), requiring PCB layout modification for implementation.

Frequently Asked Questions (FAQ)

Q: Can the A3966SLBTR-T directly replace the LB1945H-MPB-E without PCB modifications?

A: No. The A3966SLBTR-T uses a 16-PowerSOIC package (0.295" width) while the LB1945H-MPB-E uses a 28-SOP package (0.311" width). PCB footprint redesign is required. Pin configuration and signal assignments must be verified against device datasheets before implementation.

Q: What is the impact of the 650mA output current rating on the A3966SLBTR-T compared to the 800mA rating of the LB1945H-MPB-E?

A: The 150mA reduction in output current capability affects maximum motor phase current. Applications operating stepper motors at or near 800mA per phase will require current limiting adjustments or motor selection changes. Applications operating below 650mA per phase are unaffected.

Q: Are the supply voltage ranges compatible between these two devices?

A: Yes, within the specified operating window. Both devices accept 4.75V to 5.25V supply voltage. The A3966SLBTR-T extends the upper limit to 5.5V, providing additional design margin but not requiring it for LB1945H-MPB-E replacement applications.

Q: What load voltage range must be observed when substituting the A3966SLBTR-T?

A: The LB1945H-MPB-E specifies a minimum load voltage of 10V. Although the A3966SLBTR-T supports load voltages as low as 4.75V, system designs must maintain the 10V minimum to ensure compatibility with the original specification. Maximum load voltage of 28V is supported by both devices.

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

A: The A3966SLBTR-T supports -20°C to 150°C (junction temperature), extending the upper operating limit by 60°C compared to the LB1945H-MPB-E (-20°C to 90°C ambient). Applications operating within the original -20°C to 90°C range are fully compatible. Systems requiring extended high-temperature operation benefit from the A3966SLBTR-T's wider range.

Q: Do both devices have identical moisture sensitivity requirements?

A: Yes. Both the LB1945H-MPB-E and A3966SLBTR-T carry MSL 3 (168 Hours) ratings, requiring identical handling, storage, and reflow soldering procedures.