74HC138DB,112 Decoder/Demultiplexer Equivalent & Substitute Parts

Part Overview

The 74HC138DB,112 is a 1 x 3:8 decoder/demultiplexer logic IC manufactured by Nexperia USA Inc. in 16-SSOP surface mount packaging. This part is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The 74HC138 series represents a standard logic function across multiple manufacturers, with several active alternatives available that maintain electrical and mechanical compatibility.

Substiute Parts

74HC138DB,112

Nexperia USA Inc.In Stock: 124874HC138DB,112 Datasheet

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74HC138PW,118

Nexperia USA Inc.In Stock: 232074HC138PW,118 Datasheet

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MM74HC138MTC

Fairchild SemiconductorIn Stock: 5569MM74HC138MTC Datasheet

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MM74HC138MTCX

Fairchild SemiconductorIn Stock: 3471MM74HC138MTCX Datasheet

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SN74HC138DBR

Texas InstrumentsIn Stock: 2436SN74HC138DBR Datasheet

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SN74HC138PW

Texas InstrumentsIn Stock: 2329SN74HC138PW Datasheet

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SN74HC138PWR

Texas InstrumentsIn Stock: 2219SN74HC138PWR Datasheet

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SN74HC138PWT

Texas InstrumentsIn Stock: 3751SN74HC138PWT Datasheet

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SN74HC138QPWRQ1

Texas InstrumentsIn Stock: 8206SN74HC138QPWRQ1 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the 74HC138DB,112 is determined by the following criteria:

Electrical Compatibility Requirements:

• Identical circuit configuration: 1 x 3:8 decoder/demultiplexer
• Matching output current specifications: 5.2mA high and low
• Supply voltage range: 2V to 6V minimum
• Operating temperature range must meet or exceed -40°C to 125°C

Mechanical Compatibility Requirements:

• Surface mount technology
• Package type: 16-SSOP or 16-TSSOP (both 16-pin SSOP variants with compatible pinouts)
• Pin pitch and body dimensions must support direct PCB substitution

Compliance Requirements:

• RoHS3 compliance maintained
• REACH unaffected status
• Moisture sensitivity level 1 or 3 acceptable for standard applications

Substitutes are grouped into two package categories: 16-SSOP (direct footprint match) and 16-TSSOP (compatible with minor layout considerations). All listed substitutes maintain the 74HC138 base product number and identical functional specifications.

Parameter Comparison

Engineering Selection Recommendations

For Direct Footprint Replacement (16-SSOP Package): SN74HC138DBR from Texas Instruments is the primary active substitute maintaining the 16-SSOP package footprint. This part is RoHS3 compliant and currently in active production status with 2420 units in stock. Operating temperature range is -40°C to 85°C, which covers standard industrial applications but does not extend to the full 125°C upper limit of the original part.

For Extended Temperature Range (-40°C to 125°C): 74HC138PW,118 from Nexperia USA Inc. and SN74HC138QPWRQ1 from Texas Instruments both maintain the full -40°C to 125°C operating range. The Nexperia part uses 16-TSSOP packaging with active product status. The Texas Instruments SN74HC138QPWRQ1 includes AEC-Q100 automotive qualification and is available in 16-TSSOP packaging.

For 16-TSSOP Package Substitution: Multiple active alternatives exist in 16-TSSOP packaging: SN74HC138PWR (Texas Instruments, active status), MM74HC138MTC and MM74HC138MTCX (Fairchild Semiconductor, active status). All maintain electrical specifications with operating temperatures to 85°C minimum.

Compliance Considerations: All recommended substitutes maintain RoHS3 compliance and REACH unaffected status. Moisture sensitivity levels are either MSL 1 (unlimited) or MSL 3 (168 hours), both acceptable for standard PCB assembly processes.

Frequently Asked Questions (FAQ)

Q: Can I use a 16-TSSOP package part as a direct replacement for the 16-SSOP original? A: 16-TSSOP and 16-SSOP are both SSOP variants with compatible pinouts and similar body dimensions. The 16-TSSOP (0.173" width) is slightly narrower than 16-SSOP (0.209" width). PCB layout compatibility depends on your specific footprint design. If your PCB footprint accommodates the narrower TSSOP body, substitution is electrically and mechanically valid.

Q: What is the difference between the Nexperia and Texas Instruments versions? A: Both manufacturers produce functionally identical 74HC138 decoders with the same electrical specifications. The primary differences are packaging options, product status, and availability. Nexperia offers the part in both SSOP and TSSOP variants. Texas Instruments provides TSSOP variants and the automotive-qualified SN74HC138QPWRQ1. Selection should be based on package requirements and supply chain availability.

Q: Does the operating temperature range affect substitution compatibility? A: The original 74HC138DB,112 operates from -40°C to 125°C. Most active substitutes operate to -40°C to 85°C, which is sufficient for standard industrial and commercial applications. If your application requires the full 125°C upper limit, select 74HC138PW,118 or SN74HC138QPWRQ1.

Q: Are all listed substitutes RoHS3 compliant? A: All substitutes with specified RoHS status are ROHS3 compliant. Fairchild Semiconductor parts (MM74HC138MTC and MM74HC138MTCX) do not have RoHS status specified in available data but are standard logic components from this era.

Q: What is the significance of the AEC-Q100 qualification on the SN74HC138QPWRQ1? A: AEC-Q100 qualification indicates the part meets automotive industry reliability standards. This qualification is relevant only if your application requires automotive-grade components. For non-automotive applications, this qualification provides no functional advantage.

Q: Can I mix different manufacturers' parts in the same design? A: Yes. All listed substitutes are pin-compatible and electrically equivalent. Mixing manufacturers is acceptable from an engineering standpoint, though procurement and quality control processes may prefer single-source parts for consistency.