LM139AD Equivalent & Substitute Parts

Part Overview

The LM139AD is a general-purpose comparator IC manufactured by Texas Instruments, featuring four independent differential comparators with open-collector and open-drain outputs in a 14-SOIC surface-mount package. This device operates across a wide supply voltage range of 2V to 30V (single supply) or ±1V to ±15V (dual supply), making it suitable for analog signal comparison applications across industrial and commercial temperature ranges (-55°C to 125°C).

The LM139AD carries a Last Time Buy product status, indicating that Texas Instruments has discontinued this part number. Finding equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support long-term production requirements.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Part Number	LM139AD
Package Type	14-SOIC (0.154", 3.90mm Width)
Number of Comparators	4
Output Type	Open-Collector, Open-Drain
Supply Voltage Range	2V ~ 30V (Single), ±1V ~ ±15V (Dual)
Input Offset Voltage (Max)	2mV @ 30V
Input Bias Current (Max)	0.1µA @ 5V
Output Current (Typ)	20mA
Quiescent Current (Max)	2mA
Operating Temperature	-55°C ~ 125°C
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant
Product Status	Last Time Buy

Substitute Part Grouping Explanation

Substitution eligibility for the LM139AD is determined by the following critical parameters:

Primary Substitution Criteria:

Package type: 14-SOIC surface-mount form factor
Number of comparators: 4 independent elements
Output configuration: Open-collector or open-drain capability
Supply voltage compatibility: Minimum 2V to 30V single supply or equivalent dual supply range
Input offset voltage: Maximum 2mV to 7mV @ 5V or 30V
Input bias current: Maximum 0.1µA to 0.25µA @ 5V
Output current capability: Minimum 16mA typical
Operating temperature range: Support for -55°C to 125°C or -40°C to 105°C

Substitution Groups:

Group 1: Direct Texas Instruments Equivalents (Same Base Product)

LM139ADR (Cut Tape packaging variant, Active status)
LM139ADT (STMicroelectronics sourced, Active status)
LM139DT (STMicroelectronics sourced, Active status)

Group 2: LM239 Series (Extended Temperature, Compatible Output)

LM239ADT (STMicroelectronics, -40°C to 105°C)
LM239DT (STMicroelectronics, -40°C to 105°C)
LM239DR2G (onsemi, -25°C to 85°C)

Group 3: LM2901 Series (Broader Supply Range, Compatible Output)

LM2901DR2G (onsemi, 3V ~ 36V supply)
LM2901DT (STMicroelectronics, 2V ~ 32V supply)
LM2901HYDT (STMicroelectronics automotive-grade, 2V ~ 36V supply)

Group 4: Alternative Manufacturer (Rohm Semiconductor)

BA2901SF-E2 (14-SOP package, 2V ~ 36V supply, -40°C to 105°C)

Parameter Comparison

Part Number	Manufacturer	Package	Supply Voltage	Input Offset (Max)	Input Bias (Max)	Output Current (Typ)	Quiescent Current (Max)	Operating Temp	Product Status
LM139AD	Texas Instruments	14-SOIC	2V~30V / ±1V~±15V	2mV @ 30V	0.1µA @ 5V	20mA	2mA	-55°C ~ 125°C	Last Time Buy
LM139ADR	Texas Instruments	14-SOIC	2V~30V / ±1V~±15V	2mV @ 30V	0.1µA @ 5V	20mA	2mA	-55°C ~ 125°C	Active
LM139ADT	STMicroelectronics	14-SOIC	2V~32V / ±1V~±16V	2mV @ 30V	0.1µA @ 5V	16mA @ 5V	2mA	-55°C ~ 125°C	Active
LM139DT	STMicroelectronics	14-SOIC	2V~32V / ±1V~±16V	5mV @ 30V	0.25µA @ 5V	16mA @ 5V	2mA	-55°C ~ 125°C	Active
LM239ADT	STMicroelectronics	14-SOIC	2V~32V / ±1V~±16V	2mV @ 30V	0.1µA @ 5V	16mA @ 5V	2mA	-40°C ~ 105°C	Active
LM239DT	STMicroelectronics	14-SOIC	2V~32V / ±1V~±16V	5mV @ 30V	0.25µA @ 5V	16mA @ 5V	2mA	-40°C ~ 105°C	Active
LM239DR2G	onsemi	14-SOIC	3V~36V / ±1.5V~±18V	5mV @ 5V	0.25µA @ 5V	16mA @ 5V	2.5mA	-25°C ~ 85°C	Active
LM2901DR2G	onsemi	14-SOIC	3V~36V / ±1.5V~±18V	7mV @ 5V	0.25µA @ 5V	16mA @ 5V	2.5mA	-40°C ~ 105°C	Active
LM2901DT	STMicroelectronics	14-SOIC	2V~32V / ±1V~±16V	7mV @ 5V	0.25µA @ 5V	16mA @ 5V	2.5mA	-40°C ~ 125°C	Active
LM2901HYDT	STMicroelectronics	14-SOIC	2V~36V / ±1V~±18V	Not specified	Not specified	Not specified	2.5mA	Not specified	Active
BA2901SF-E2	Rohm Semiconductor	14-SOIC	2V~36V / ±1V~±18V	7mV @ 5V	0.25µA @ 5V	16mA @ 5V	2mA	-40°C ~ 105°C	Active

Engineering Selection Recommendations

Tier 1 - Recommended Direct Substitutes (Highest Compatibility):

LM139ADR is the primary recommended substitute. Manufactured by Texas Instruments with identical electrical specifications to the LM139AD, this part maintains full parameter compatibility including 2mV input offset voltage, 0.1µA input bias current, and 20mA output current. The only difference is packaging format (Cut Tape & Digi-Reel versus Tube), which does not affect electrical performance. Product status is Active with 21,330 units in stock, ensuring supply continuity.

Tier 2 - Compatible Substitutes (Minor Parameter Variations):

LM139ADT and LM139DT (STMicroelectronics) are functionally equivalent with identical 14-SOIC packaging and operating temperature range (-55°C to 125°C). Both maintain the four-comparator configuration and open-collector output type. Parameter variations are minimal: input offset voltage increases to 5mV maximum on LM139DT, and output current reduces to 16mA typical. These parts are Active with substantial inventory (4,825 and 18,338 units respectively).

LM239ADT maintains the original 2mV input offset specification and 0.1µA input bias current but operates within a narrower temperature range (-40°C to 105°C). This substitution is suitable for applications not requiring the full -55°C lower temperature limit. Inventory is 15,360 units.

Tier 3 - Extended-Range Substitutes (Broader Supply Voltage):

LM2901 series parts (LM2901DR2G, LM2901DT, LM2901HYDT) and LM239DR2G support extended supply voltage ranges (up to 36V) compared to the LM139AD (30V maximum). These parts are suitable for applications requiring higher supply voltages. Input offset voltage increases to 5-7mV, and quiescent current increases to 2.5mA. LM2901HYDT includes automotive-grade qualification (AEC-Q100) for temperature-cycling and reliability-critical applications.

Tier 4 - Alternative Manufacturer:

BA2901SF-E2 (Rohm Semiconductor) provides a non-Texas Instruments alternative with compatible 14-SOIC packaging and extended supply range (2V to 36V). Operating temperature range is -40°C to 105°C. Input offset voltage is 7mV maximum. This option is suitable when Texas Instruments sourcing is unavailable and broader supply voltage support is required.

Selection Criteria by Application:

Standard industrial applications with -55°C requirement: LM139ADR or LM139ADT
Commercial temperature range (-40°C to 105°C): LM239ADT or LM239DT
Extended supply voltage (up to 36V): LM2901DR2G, LM2901DT, or BA2901SF-E2
Automotive or high-reliability applications: LM2901HYDT (AEC-Q100 qualified)

All substitute parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating, ensuring compatibility with standard manufacturing and storage practices.

Frequently Asked Questions (FAQ)

Q: Can I use LM139ADR as a direct replacement for LM139AD?

A: Yes. LM139ADR is manufactured by Texas Instruments with identical electrical specifications (2mV input offset, 0.1µA input bias, 20mA output current, -55°C to 125°C operating range). The only difference is packaging format (Cut Tape & Digi-Reel versus Tube), which does not affect circuit performance. This is the recommended substitute.

Q: What is the difference between LM139 and LM239 series?

A: Both are four-comparator ICs in 14-SOIC packages with open-collector outputs. The primary difference is operating temperature range: LM139 supports -55°C to 125°C, while LM239 typically operates -40°C to 105°C. LM239 is suitable for commercial and industrial applications not requiring the extended low-temperature specification.

Q: Why do some substitutes have higher input offset voltage (5-7mV vs. 2mV)?

A: Input offset voltage variation reflects manufacturing process differences between manufacturers and product lines. Higher offset voltage (5-7mV) remains within acceptable limits for most comparator applications but may require circuit-level compensation in precision applications. Verify offset voltage requirements against your specific application specifications before selection.

Q: Can I use LM2901 series parts instead of LM139?

A: Yes, with considerations. LM2901 parts support extended supply voltage ranges (up to 36V versus 30V for LM139) and maintain the four-comparator, open-collector output configuration. However, input offset voltage increases to 7mV, and quiescent current increases to 2.5mA. These differences are acceptable for most applications but should be verified against circuit design requirements.

Q: What is the difference between 14-SOIC and 14-SOP packages?

A: Both are 14-pin surface-mount packages with similar pin spacing (0.154" width for SOIC, 0.173" for SOP). They are mechanically and electrically compatible for most applications. BA2901SF-E2 uses 14-SOP packaging and is functionally equivalent to 14-SOIC variants. Verify PCB footprint compatibility before selection.

Q: Are all substitute parts RoHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance and MSL 1 (Unlimited) moisture sensitivity rating, ensuring compatibility with standard manufacturing processes and storage requirements.

Q: Which substitute should I choose for automotive applications?

A: LM2901HYDT is qualified to AEC-Q100 automotive standards and supports extended supply voltage (2V to 36V). This part is recommended for temperature-cycling and reliability-critical automotive applications. Verify specific automotive qualification requirements against your application specifications.

Q: Can I mix different substitute parts in the same design?

A: Yes, provided all selected parts meet the minimum electrical specifications required by your circuit design. Verify input offset voltage, input bias current, output current, supply voltage range, and operating temperature range compatibility. Document part selection rationale for manufacturing and quality control purposes.

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