BA17805T Linear Voltage Regulator - Equivalent & Substitute Parts

Part Overview

The BA17805T is a linear voltage regulator IC manufactured by Rohm Semiconductor, designed to provide a fixed 5V output at 1A current capacity in a TO-220-3 package. This device is classified as a positive fixed output regulator within the Power Management (PMIC) category and is currently marked as Not For New Designs, indicating it has been superseded in Rohm's product portfolio. Finding equivalent substitute parts is necessary for applications requiring continued supply, design flexibility, or when the primary part becomes unavailable.

Substiute Parts

BA17805T

Rohm SemiconductorIn Stock: 8150BA17805T Datasheet

Current PartRFQ

LM2940CT-5.0/NOPB

Texas InstrumentsIn Stock: 20937LM2940CT-5.0/NOPB Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BA17805T is determined by strict alignment of the following electrical and mechanical parameters:

• Output Voltage: Must be fixed at 5V
• Output Current Capacity: Minimum 1A
• Package Type: TO-220-3 (Through Hole, 3-pin configuration)
• Input Voltage Range: Must accommodate up to 25V minimum
• Output Configuration: Positive fixed output
• Mounting Type: Through Hole

The LM2940CT-5.0/NOPB from Texas Instruments meets all substitution criteria. Both devices share identical output voltage and current specifications, compatible package geometry, and equivalent electrical performance within the specified operating parameters.

Parameter Comparison

Engineering Selection Recommendations

The LM2940CT-5.0/NOPB is a direct functional substitute for the BA17805T. Both devices are ROHS3 compliant and REACH unaffected, meeting equivalent regulatory requirements. The LM2940CT-5.0/NOPB carries Active product status, ensuring continued availability and support from Texas Instruments, whereas the BA17805T is marked Not For New Designs.

The LM2940CT-5.0/NOPB demonstrates superior performance in dropout voltage (1V versus 2V), which may provide operational advantages in applications with marginal input voltage headroom. The extended operating temperature range (0°C ~ 125°C versus -40°C ~ 85°C) of the LM2940CT-5.0/NOPB accommodates broader environmental conditions. The BA17805T exhibits lower quiescent current (4.5 mA versus 15 mA) and higher PSRR (78dB versus 72dB), which may be relevant for power-sensitive or noise-critical applications.

Selection should be based on specific application requirements regarding temperature range, quiescent current constraints, and dropout voltage tolerance.

Frequently Asked Questions (FAQ)

Q: Can the LM2940CT-5.0/NOPB directly replace the BA17805T in existing designs?

A: Yes. Both devices provide identical 5V fixed output at 1A in TO-220-3 packages. Pin configuration and electrical output specifications are compatible. Verify that the application can tolerate the differences in quiescent current and dropout voltage listed in the parameter comparison table.

Q: What is the primary difference between these two regulators?

A: The LM2940CT-5.0/NOPB offers lower dropout voltage (1V versus 2V) and extended operating temperature range (0°C ~ 125°C versus -40°C ~ 85°C). The BA17805T has lower quiescent current (4.5 mA versus 15 mA) and higher PSRR (78dB versus 72dB).

Q: Are both parts RoHS compliant?

A: Yes. Both the BA17805T and LM2940CT-5.0/NOPB are ROHS3 compliant and REACH unaffected.

Q: Why is the BA17805T marked as Not For New Designs?

A: This designation indicates that Rohm Semiconductor has discontinued active development and promotion of this part. The LM2940CT-5.0/NOPB, with Active status, is the recommended choice for new applications requiring a 5V 1A linear regulator in TO-220-3 packaging.

Q: Are there any package differences between these parts?

A: No. Both devices use the TO-220-3 package with identical pin configuration and mechanical dimensions, enabling direct board-level substitution.

Q: What is the impact of the quiescent current difference on system design?

A: The BA17805T draws 4.5 mA quiescent current versus 15 mA for the LM2940CT-5.0/NOPB. In applications where the regulator operates continuously with minimal load current, this 10.5 mA difference may impact overall system power consumption. Evaluate based on duty cycle and load profile.