TPS54540BDDAR Equivalent & Substitute Parts

Part Overview

The TPS54540BDDAR is an active, production-status buck switching regulator IC from Texas Instruments, designed for step-down voltage conversion applications. It delivers 5A output current with adjustable output voltage ranging from 0.8V to 41.1V, operating across a 4.5V to 42V input range. The device features Eco-Mode™ operation and is housed in an 8-PowerSOIC package with exposed pad for enhanced thermal management. Finding equivalent substitute parts is necessary when addressing supply chain constraints, lead time requirements, or specific application compatibility needs while maintaining electrical and mechanical performance standards.

Substiute Parts

TPS54540BDDAR

Texas InstrumentsIn Stock: 16841TPS54540BDDAR Datasheet

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AP64500SP-13

Diodes IncorporatedIn Stock: 67166AP64500SP-13 Datasheet

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RT6345GSP

Richtek USA Inc.In Stock: 2693RT6345GSP Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the TPS54540BDDAR are qualified based on the following critical parameters that determine functional equivalence:

• Topology & Function: Step-down buck converter with positive adjustable output
• Output Current Rating: 5A minimum
• Voltage Input Range: Minimum 4.5V, maximum 42V (or compatible overlap)
• Voltage Output Range: Adjustable from 0.8V minimum
• Package Compatibility: 8-SOIC or 8-PowerSOIC with exposed pad (0.154", 3.90mm width)
• Mounting Type: Surface mount
• Compliance: ROHS3 compliant, active product status

The identified substitutes—AP64500SP-13 (Diodes Incorporated) and RT6345GSP (Richtek USA Inc.)—meet these core electrical and mechanical requirements, enabling direct replacement in applications where the TPS54540BDDAR supply is constrained.

Parameter Comparison

Engineering Selection Recommendations

AP64500SP-13 (Diodes Incorporated): This substitute offers the lowest input voltage threshold (3.8V) and includes integrated synchronous rectification for improved efficiency. It maintains the 5A output current and adjustable 0.8V minimum output voltage. The MSL rating of 1 provides superior moisture tolerance for extended storage. All three devices share identical package dimensions and ROHS3 compliance. The AP64500SP-13 is suitable for applications where lower input voltage operation or enhanced efficiency is beneficial.

RT6345GSP (Richtek USA Inc.): This substitute matches the maximum input voltage specification (42V) and output voltage ceiling (42V) of the TPS54540BDDAR, providing the closest electrical envelope alignment. It maintains 5A output current and adjustable output voltage characteristics. Operating temperature range extends to -40°C to 125°C, which is lower than the TPS54540BDDAR's 150°C maximum. The RT6345GSP is appropriate for applications requiring maximum input/output voltage compatibility within standard industrial temperature ranges.

All three devices are active products with ROHS3 compliance and surface-mount 8-SOIC packaging with exposed pads, ensuring mechanical and regulatory compatibility.

Frequently Asked Questions (FAQ)

Q: Can AP64500SP-13 replace TPS54540BDDAR in all applications?

A: AP64500SP-13 is electrically compatible for applications operating within its specified input range (3.8V to 40V) and output voltage range (0.8V to 40V). The maximum output voltage of 40V is 1.1V lower than the TPS54540BDDAR's 41.1V specification. Applications requiring output voltages above 40V must use RT6345GSP or the original TPS54540BDDAR.

Q: What is the significance of the synchronous rectifier in AP64500SP-13?

A: The integrated synchronous rectifier in AP64500SP-13 reduces conduction losses compared to the non-synchronous designs of TPS54540BDDAR and RT6345GSP, resulting in improved efficiency and reduced thermal dissipation. This feature does not affect pin compatibility or functional operation.

Q: Are the package dimensions identical across all three devices?

A: Yes. All three devices use 8-SOIC (0.154", 3.90mm width) packages with exposed pads. The TPS54540BDDAR is designated 8-PowerSOIC, while AP64500SP-13 and RT6345GSP are designated 8-SOIC with exposed pad. These designations refer to the same physical footprint and are mechanically interchangeable.

Q: Which substitute has the best moisture sensitivity rating?

A: AP64500SP-13 has MSL rating 1 (Unlimited storage), compared to TPS54540BDDAR's MSL 2 (1 Year) and RT6345GSP's MSL 3 (168 Hours). Lower MSL ratings indicate superior moisture tolerance and longer shelf life without baking requirements.

Q: What is the maximum operating temperature difference between substitutes?

A: TPS54540BDDAR operates to 150°C (TJ), while RT6345GSP operates to 125°C (TJ). For applications requiring operation above 125°C, the TPS54540BDDAR or AP64500SP-13 (operating temperature not specified) should be selected.

Q: Are all three devices suitable for 42V input applications?

A: TPS54540BDDAR and RT6345GSP both specify 42V maximum input voltage. AP64500SP-13 specifies 40V maximum input voltage. For applications requiring 42V input operation, use TPS54540BDDAR or RT6345GSP.