BA178M08T Linear Voltage Regulator - Equivalent & Substitute Parts

Part Overview

The BA178M08T is a linear voltage regulator IC manufactured by Rohm Semiconductor, designed to deliver a fixed positive 8V output at 500mA in a TO-220-3 package. This device is classified as Not For New Designs, indicating it has been superseded in Rohm's product portfolio.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, maintenance of existing designs, or when original stock becomes unavailable.

Substiute Parts

BA178M08T

Rohm SemiconductorIn Stock: 1164BA178M08T Datasheet

Current PartRFQ

UA78M08CKCS

Texas InstrumentsIn Stock: 1157UA78M08CKCS Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the BA178M08T is determined by the following critical parameters:

• Fixed Output Voltage: 8V (non-negotiable for direct replacement)
• Output Current Rating: Minimum 500mA required
• Package Type: TO-220-3 (mechanical and thermal compatibility)
• Input Voltage Range: Must accommodate maximum 23V input
• Dropout Voltage: Should not exceed 2V at rated current
• Operating Temperature: Must support -40°C ~ 85°C range or broader
• Regulatory Compliance: ROHS3 compliance required for modern supply chains

The UA78M08CKCS from Texas Instruments meets these substitution criteria as a direct functional equivalent with compatible electrical and mechanical specifications.

Parameter Comparison

Engineering Selection Recommendations

The UA78M08CKCS is a suitable substitute for the BA178M08T based on the following factors:

• Both devices deliver 8V fixed output at 500mA in identical TO-220-3 packages
• The UA78M08CKCS accepts higher maximum input voltage (25V vs. 23V), providing greater design margin
• The UA78M08CKCS features integrated protection (Over Current, Over Temperature, Short Circuit), enhancing circuit reliability
• Both parts maintain ROHS3 compliance and REACH Unaffected status
• The UA78M08CKCS operates across a wider temperature range (0°C ~ 125°C), though the BA178M08T's -40°C ~ 85°C range may be required for specific applications

Selection should be based on application temperature requirements and whether the extended protection features of the UA78M08CKCS provide benefit to the end application.

Frequently Asked Questions (FAQ)

Q: Can the UA78M08CKCS directly replace the BA178M08T without circuit modifications?

A: Yes. Both devices are 8V fixed output regulators in TO-220-3 packages with 500mA output current ratings. Pin configuration and electrical behavior are compatible for direct substitution in existing PCB layouts.

Q: What is the difference in dropout voltage between these parts?

A: The BA178M08T specifies 2V dropout at 500mA. The UA78M08CKCS specifies 2V dropout at 350mA. At full 500mA output, the UA78M08CKCS dropout voltage may be slightly higher. Applications with tight input voltage margins should verify performance at maximum load current.

Q: Does the operating temperature range difference affect substitution?

A: The BA178M08T operates from -40°C ~ 85°C, while the UA78M08CKCS operates from 0°C ~ 125°C. If your application requires operation below 0°C, the BA178M08T is required. For standard industrial and commercial temperature ranges, the UA78M08CKCS is suitable.

Q: Are there compliance or supply chain advantages to using the UA78M08CKCS?

A: Both parts are ROHS3 compliant and REACH Unaffected. The UA78M08CKCS is from Texas Instruments, a major semiconductor manufacturer with established global distribution. The BA178M08T is marked Not For New Designs, indicating Rohm has transitioned away from this product line.

Q: What do the protection features on the UA78M08CKCS provide?

A: Over Current, Over Temperature, and Short Circuit protection are integrated into the UA78M08CKCS. These features automatically limit output current and disable the regulator if junction temperature exceeds safe limits, providing additional circuit protection compared to the BA178M08T.