BA178M05T Linear Voltage Regulator - Equivalent & Substitute Parts

Part Overview

The BA178M05T is a linear voltage regulator IC manufactured by Rohm Semiconductor, designed to provide a fixed positive 5V output at 500mA. This is a through-hole component in TO-220-3 packaging intended for power management applications requiring stable DC voltage regulation.

The BA178M05T carries a "Not For New Designs" product status, indicating that Rohm Semiconductor has discontinued active development and support for this component. This status necessitates identifying functionally equivalent substitute parts for ongoing production, maintenance, and new system implementations where 5V linear regulation is required.

Substiute Parts

BA178M05T

Rohm SemiconductorIn Stock: 9991BA178M05T Datasheet

Current PartRFQ

UA78M05IKCS

Texas InstrumentsIn Stock: 9026UA78M05IKCS Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BA178M05T is determined by the following critical electrical and mechanical parameters:

• Fixed output voltage of 5V
• Minimum output current capability of 500mA
• Maximum input voltage rating of 25V or higher
• TO-220-3 through-hole package compatibility
• ROHS3 compliance for regulatory alignment
• Operating temperature range support (minimum -40°C to 85°C)

The UA78M05IKCS from Texas Instruments meets all substitution criteria. Both devices are positive fixed linear voltage regulators with identical output voltage and current specifications, compatible package types, and equivalent regulatory compliance. The substitute maintains electrical performance within acceptable engineering tolerances for this component category.

Parameter Comparison

Engineering Selection Recommendations

The UA78M05IKCS is a direct functional substitute for the BA178M05T based on electrical equivalence and regulatory compliance. Both components are ROHS3 compliant and rated for the same input voltage and output specifications.

The UA78M05IKCS offers extended operating temperature range (-40°C to 125°C versus -40°C to 85°C) and integrated protection features (over current, over temperature, short circuit) not specified in the BA178M05T datasheet. These additional capabilities provide enhanced reliability in thermal stress conditions and fault scenarios.

Both components carry obsolete or discontinued product status, indicating limited long-term availability. For applications requiring active manufacturer support and extended component lifecycle, evaluation of current-generation linear regulators or switching power management solutions should be considered as part of long-term design strategy.

Frequently Asked Questions (FAQ)

Q: Can the UA78M05IKCS directly replace the BA178M05T in existing designs?

A: Yes. Both devices are positive fixed 5V linear regulators in TO-220-3 packaging with 500mA output current capability. Pin configuration and electrical performance are compatible for direct board-level substitution.

Q: What is the significance of the voltage dropout specification difference?

A: The BA178M05T specifies 2V dropout at 500mA, while the UA78M05IKCS specifies 2V dropout at 350mA. At full 500mA load, the UA78M05IKCS may exhibit higher dropout voltage. Applications operating near the maximum input voltage limit should verify adequate headroom for regulation.

Q: Why does the UA78M05IKCS have a wider operating temperature range?

A: The extended range (-40°C to 125°C) reflects Texas Instruments' component qualification and thermal design. Applications limited to -40°C to 85°C operation will function within both specifications. Applications requiring operation above 85°C benefit from the wider range of the substitute.

Q: Are there packaging differences between these components?

A: Both use TO-220-3 through-hole packaging. The BA178M05T is supplied in bulk packaging, while the UA78M05IKCS is supplied in tube packaging. This affects handling and storage but does not impact electrical performance or board-level compatibility.

Q: What protection features does the UA78M05IKCS provide?

A: The UA78M05IKCS includes over current, over temperature, and short circuit protection. The BA178M05T datasheet does not specify these protections. The substitute provides enhanced fault tolerance in applications subject to load transients or thermal stress.

Q: Are both components compliant with current regulatory standards?

A: Yes. Both the BA178M05T and UA78M05IKCS are ROHS3 compliant and REACH unaffected, meeting current environmental and hazardous substance regulations for electronic components.