BA17818T Linear Voltage Regulator - Equivalent & Substitute Parts

Part Overview

The BA17818T is a linear voltage regulator IC manufactured by Rohm Semiconductor, designed for positive fixed 18V output applications with 1A current capacity in a TO-220-3 through-hole package. This device delivers regulated 18V output from input voltages up to 33V with a typical dropout voltage of 2V at full load.

The BA17818T carries a "Not For New Designs" product status, indicating that Rohm Semiconductor has discontinued active development and support for this component. Organizations requiring this functionality for new or ongoing production must identify equivalent substitute parts that maintain electrical and mechanical compatibility while offering active manufacturer support and improved availability.

Substiute Parts

BA17818T

Rohm SemiconductorIn Stock: 951BA17818T Datasheet

Current PartRFQ

MC7818BTG

onsemiIn Stock: 17164MC7818BTG Datasheet

SimilarRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the BA17818T are identified based on the following critical parameters that determine functional and mechanical compatibility:

• Output Voltage: Fixed 18V output (primary functional requirement)
• Output Current Rating: 1A minimum capacity
• Package Type: TO-220-3 through-hole configuration (mechanical compatibility)
• Input Voltage Range: Support for input voltages up to 33V minimum
• Dropout Voltage: Maximum 2V at rated current
• Regulatory Compliance: ROHS3 compliance and REACH unaffected status

The MC7818BTG from onsemi meets all substitution criteria. This part maintains identical output voltage and current specifications, uses the same TO-220-3 package footprint, and operates within compatible input voltage and dropout voltage parameters. The MC7818BTG offers active product status with enhanced availability and manufacturer support.

Parameter Comparison

Engineering Selection Recommendations

The MC7818BTG from onsemi is the direct substitute for the BA17818T. Selection of the MC7818BTG is supported by the following engineering factors:

Regulatory Compliance: Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring compatibility with current environmental and regulatory requirements.

Product Status: The MC7818BTG carries active product status, indicating ongoing manufacturer support, continued availability, and suitability for new design implementations. The BA17818T's "Not For New Designs" status necessitates transition to an active alternative.

Electrical Compatibility: The MC7818BTG delivers identical output voltage (18V) and current (1A) specifications with matching dropout voltage performance (2V @ 1A). The higher maximum input voltage rating (35V vs. 33V) and extended operating temperature range (-40°C to 125°C vs. -40°C to 85°C) provide additional design margin without compromising functionality.

Mechanical Compatibility: Both parts use identical TO-220-3 through-hole packaging, enabling direct PCB footprint compatibility and eliminating layout redesign requirements.

Additional Features: The MC7818BTG includes integrated over-temperature and short-circuit protection, providing enhanced reliability compared to the BA17818T.

Frequently Asked Questions (FAQ)

Q: Can the MC7818BTG be used as a direct replacement for the BA17818T without PCB modifications?

A: Yes. Both parts use identical TO-220-3 through-hole packaging with the same pin configuration and spacing. Direct substitution on existing PCBs is possible without layout changes.

Q: What is the significance of the BA17818T's "Not For New Designs" status?

A: This designation indicates that Rohm Semiconductor has ended active development and support for this component. New product designs should transition to active alternatives such as the MC7818BTG to ensure long-term availability, manufacturer support, and compliance with current industry standards.

Q: Are there differences in quiescent current between the BA17818T and MC7818BTG?

A: The MC7818BTG draws 8 mA quiescent current compared to the BA17818T's 4.5 mA. This 4.6 mA difference is acceptable for most applications and does not affect core functionality. Applications with strict power consumption requirements should evaluate this parameter against specific design constraints.

Q: Does the MC7818BTG's higher maximum input voltage (35V vs. 33V) affect circuit design?

A: No. The higher input voltage rating provides additional design margin and protection against input voltage transients. Existing circuits designed for the BA17818T operate within the MC7818BTG's input voltage specification without modification.

Q: What protection features does the MC7818BTG provide that the BA17818T does not?

A: The MC7818BTG includes integrated over-temperature and short-circuit protection. These features enhance device reliability and circuit protection without requiring external components.

Q: Are both parts RoHS compliant?

A: Yes. Both the BA17818T and MC7818BTG are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements for electronic components.