BU4081B Equivalent & Substitute Parts

Part Overview

The BU4081B is a 4-channel AND gate logic IC manufactured by Rohm Semiconductor in 14-DIP packaging. This device implements four independent 2-input AND gates on a single integrated circuit, operating across a supply voltage range of 3V to 16V. The BU4081B is classified as obsolete, making equivalent substitute parts necessary for new designs and ongoing production requirements. The CD4081BE from Texas Instruments serves as the primary functional equivalent for this application.

Substiute Parts

BU4081B

Rohm SemiconductorIn Stock: 2399BU4081B Datasheet

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CD4081BE

Texas InstrumentsIn Stock: 1470CD4081BE Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the BU4081B with the CD4081BE is based on the following critical parameters:

• Logic Function: Both devices implement identical 4-channel 2-input AND gate logic
• Circuit Count & Input Configuration: Both contain 4 circuits with 2 inputs per circuit
• Package Type: Both use 14-DIP (0.300", 7.62mm) through-hole packaging, ensuring mechanical and electrical pin compatibility
• Supply Voltage Overlap: The CD4081BE operates at 3V ~ 18V, which encompasses the BU4081B operating range of 3V ~ 16V
• Input Logic Levels: Both devices share identical input logic level thresholds (Low: 1.5V ~ 4V, High: 4.6V ~ 11V)
• Compliance Standards: Both are ROHS3 compliant and REACH unaffected

The CD4081BE is suitable as a direct replacement where the BU4081B is no longer available.

Parameter Comparison

Engineering Selection Recommendations

The CD4081BE is the appropriate substitute for the BU4081B based on the following factors:

• Functional Equivalence: Both devices implement identical AND gate logic with matching pin configurations and circuit counts
• Package Compatibility: Identical 14-DIP through-hole packaging ensures direct board-level replacement without layout modifications
• Supply Voltage Coverage: The CD4081BE's extended supply range (3V ~ 18V) fully encompasses the BU4081B operating window
• Active Product Status: The CD4081BE is actively manufactured by Texas Instruments, ensuring long-term availability and supply chain reliability
• Regulatory Compliance: Both devices meet ROHS3 and REACH requirements, maintaining compliance in regulated applications
• Extended Temperature Range: The CD4081BE supports -55°C ~ 125°C operation, providing broader environmental capability than the BU4081B

The CD4081BE is available in active production with 1360 pieces in stock, providing immediate availability for design transitions.

Frequently Asked Questions (FAQ)

Q: Can the CD4081BE directly replace the BU4081B without circuit modifications?

A: Yes. Both devices share identical pin configurations, logic function, and 14-DIP packaging. No circuit modifications are required for direct substitution.

Q: What are the differences in propagation delay between these devices?

A: The BU4081B specifies 50ns maximum propagation delay at 15V with 50pF load, while the CD4081BE specifies 90ns under identical conditions. Applications with strict timing requirements should verify that the CD4081BE delay specification meets system performance criteria.

Q: Are there differences in output current capability?

A: Yes. The BU4081B provides 1.2mA high and 3mA low output current, while the CD4081BE provides 3.4mA for both high and low outputs. The CD4081BE offers higher and more balanced output drive capability.

Q: Does the CD4081BE support the same supply voltage range as the BU4081B?

A: The CD4081BE supports 3V ~ 18V, which fully encompasses the BU4081B range of 3V ~ 16V. The extended upper limit provides additional design margin.

Q: What is the quiescent current difference?

A: The BU4081B specifies 4 µA maximum quiescent current, while the CD4081BE specifies 1 µA. The CD4081BE offers superior power efficiency in standby conditions.

Q: Are both devices RoHS compliant?

A: Yes. Both the BU4081B and CD4081BE are ROHS3 compliant and REACH unaffected, meeting current regulatory requirements for electronic components.

Q: Why is the BU4081B listed as obsolete?

A: The BU4081B is no longer in active production by Rohm Semiconductor. The CD4081BE from Texas Instruments provides equivalent functionality and is actively manufactured, making it the recommended solution for new designs and production continuity.