LM5642MTC Buck Regulator Controller IC Equivalent & Substitute Parts

Part Overview

The LM5642MTC is a buck regulator positive output step-down DC-DC controller IC manufactured by Texas Instruments in a 28-TSSOP surface mount package. This device functions as a transistor driver for two-phase buck topology applications with a 200kHz switching frequency and 98.9% maximum duty cycle. The main part number LM5642MTC is currently in Last Time Buy status with 15,433 pieces in stock. Finding equivalent and substitute parts is necessary due to the Last Time Buy designation, which indicates this specific configuration will no longer be manufactured after existing inventory is depleted. Direct manufacturer equivalents and parametric alternatives are available to ensure design continuity and supply chain reliability.

Substiute Parts

LM5642MTC

Texas InstrumentsIn Stock: 15521LM5642MTC Datasheet

Current PartRFQ

LM5642MTC/NOPB

Texas InstrumentsIn Stock: 1215LM5642MTC/NOPB Datasheet

DirectRFQ

LM5642XMT/NOPB

Texas InstrumentsIn Stock: 54101LM5642XMT/NOPB Datasheet

Parametric EquivalentRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the LM5642MTC is determined by strict equivalence in the following critical parameters:

Mandatory Matching Parameters:

• Manufacturer: Texas Instruments
• Base Product Number: LM5642
• Package / Case: 28-TSSOP (0.173", 4.40mm Width)
• Output Type: Transistor Driver
• Function: Step-Down
• Output Configuration: Positive
• Topology: Buck
• Number of Outputs: 2
• Number of Phases: 2
• Voltage Supply Range: 4.5V ~ 36V
• Duty Cycle (Max): 98.9%
• Synchronous Rectifier: Yes
• Clock Sync: Yes
• Control Features: Current Limit, Enable, Soft Start
• Operating Temperature Range: -40°C ~ 125°C (TJ)
• RoHS Status: ROHS3 Compliant
• Moisture Sensitivity Level: 3 (168 Hours)

Allowable Variation:

• Switching Frequency: 200kHz (main part) to 375kHz (parametric equivalent) — higher switching frequency is acceptable for buck controller applications as it does not degrade performance in standard step-down configurations
• Product Status: Last Time Buy (main part) to Active (substitute parts) — Active status ensures continued availability
• Inventory levels: Vary based on supplier stock

Parameter Comparison

Engineering Selection Recommendations

LM5642MTC/NOPB is the direct manufacturer equivalent. This part carries the /NOPB suffix designation and maintains identical electrical and mechanical specifications to the main part number LM5642MTC. It is currently in Active product status, ensuring long-term availability and supply chain continuity. This part is the primary recommendation for direct replacement in new designs or production transitions from Last Time Buy inventory.

LM5642XMT/NOPB is a parametric equivalent with a higher switching frequency of 375kHz compared to the 200kHz of the main part. All other electrical parameters, control features, package specifications, and compliance certifications remain identical. This part is in Active status with the highest available inventory (54,037 pieces). The increased switching frequency does not compromise functionality in standard buck regulator applications and may offer benefits in applications where reduced output ripple or smaller passive component sizing is advantageous. This part is suitable for designs where the higher switching frequency is compatible with the power stage design.

Both substitute parts are ROHS3 compliant and REACH unaffected, maintaining full regulatory compliance with the original part number.

Frequently Asked Questions (FAQ)

Q: Can LM5642MTC/NOPB be used as a direct replacement for LM5642MTC?

A: Yes. LM5642MTC/NOPB is a direct manufacturer equivalent with identical electrical specifications, package configuration, and performance characteristics. The /NOPB suffix indicates lead-free and halogen-free compliance. Both parts are functionally interchangeable in all applications.

Q: What is the difference between LM5642MTC and LM5642XMT/NOPB?

A: The primary difference is switching frequency. LM5642MTC operates at 200kHz, while LM5642XMT/NOPB operates at 375kHz. All other parameters including output configuration, topology, control features, and package are identical. The higher switching frequency of the LM5642XMT/NOPB may reduce output voltage ripple and allow for smaller passive components in the power stage.

Q: Are all three parts in the same package?

A: Yes. All three parts use the 28-TSSOP surface mount package with 0.173" width and 4.40mm height. PCB layouts and footprints are identical across all three part numbers.

Q: Why is LM5642MTC designated as Last Time Buy?

A: Last Time Buy status indicates that Texas Instruments will discontinue manufacturing this specific part number configuration after existing inventory is depleted. Customers requiring this device should transition to the Active equivalent parts LM5642MTC/NOPB or LM5642XMT/NOPB to ensure continued supply availability.

Q: Are there any compliance or certification differences between these parts?

A: No. All three parts are ROHS3 compliant, REACH unaffected, and carry identical Moisture Sensitivity Level (MSL) ratings of 3 (168 Hours). Regulatory compliance is equivalent across all substitute options.

Q: Which part should I select for a new design?

A: For new designs requiring 200kHz switching frequency, select LM5642MTC/NOPB. For applications where higher switching frequency is acceptable or beneficial, LM5642XMT/NOPB offers superior inventory availability and identical core functionality.