LM139 MD8 Equivalent & Substitute Parts

Part Overview

The LM139 MD8 is a low-power, low-offset voltage general-purpose comparator manufactured by Texas Instruments in die form. This quad comparator features open-collector/open-drain output configuration and operates across a wide supply voltage range of 5V to 30V (single supply) or ±2.5V to ±15V (dual supply). The device is classified as Active product status and complies with ROHS3 standards.

Die-form components like the LM139 MD8 present sourcing challenges due to limited availability in certain markets and specialized handling requirements. Equivalent packaged alternatives provide identical functional performance while offering improved availability, standard packaging options, and simplified integration into production environments.

Key Parameters

Parameter	Value	Condition
Number of Elements	4	Quad comparator configuration
Output Type	Open-Collector, Open-Drain	Primary output configuration
Voltage - Supply, Single/Dual (±)	5V ~ 30V, ±2.5V ~ 15V	Operating range
Voltage - Input Offset (Max)	5mV @ 30V	DC offset specification
Current - Input Bias (Max)	1000pA @ 5V	Input leakage current
Current - Quiescent (Max)	3mA	Supply current at rest
Propagation Delay (Max)	700ns (Typ)	Response time specification
Hysteresis	10mV	Threshold window
Operating Temperature	-55°C ~ 125°C	Full industrial range
Mounting Type	Surface Mount	Die form
RoHS Status	ROHS3 Compliant	Environmental compliance

Substitute Part Grouping Explanation

Substitution of the LM139 MD8 is determined by the following critical parameters:

Functional Equivalence Criteria:

Quad comparator configuration (4 elements minimum)
Open-collector or open-drain output capability
Supply voltage range compatibility: minimum 5V single supply or ±2.5V dual supply support
Input offset voltage specification ≤ 5mV
Input bias current ≤ 1000pA
Quiescent current ≤ 3mA
Operating temperature range including -55°C to 125°C or equivalent industrial coverage
Active product status
ROHS3 compliance

Packaging Considerations: Substitute parts are available in industry-standard surface-mount packages (14-SOIC, 14-TSSOP, 16-QFN) that provide superior availability and integration compared to die form. These packages maintain electrical equivalence while offering practical manufacturing advantages.

Manufacturer Diversity: Qualified substitutes are sourced from STMicroelectronics, onsemi, and other established semiconductor manufacturers, ensuring supply chain resilience and long-term availability.

Parameter Comparison

Parameter	LM139 MD8	LM239APT	LM239DR2G	LM239PT	LM2901DT	LM2901HYDT	LM2901VDTBR2G	LM339PT
Manufacturer	Texas Instruments	STMicroelectronics	onsemi	STMicroelectronics	STMicroelectronics	STMicroelectronics	onsemi	STMicroelectronics
Number of Elements	4	4	4	4	4	4	4	4
Output Type	Open-Collector, Open-Drain	CMOS, DTL, ECL, MOS, Open-Collector, TTL	CMOS, Open-Collector, TTL	CMOS, DTL, ECL, MOS, Open-Collector, TTL	CMOS, DTL, ECL, MOS, Open-Collector, TTL	CMOS, DTL, ECL, MOS, Open-Collector, TTL	CMOS, Open-Collector, TTL	CMOS, DTL, ECL, MOS, Open-Collector, TTL
Voltage - Supply, Single/Dual (±)	5V ~ 30V, ±2.5V ~ 15V	2V ~ 32V, ±1V ~ 16V	3V ~ 36V, ±1.5V ~ 18V	2V ~ 32V, ±1V ~ 16V	2V ~ 32V, ±1V ~ 16V	2V ~ 36V, ±1V ~ 18V	3V ~ 36V, ±1.5V ~ 18V	2V ~ 32V, ±1V ~ 16V
Voltage - Input Offset (Max)	5mV @ 30V	2mV @ 30V	5mV @ 5V	5mV @ 30V	7mV @ 5V	Not specified	7mV @ 5V	5mV @ 30V
Current - Input Bias (Max)	1000pA @ 5V	0.1µA @ 5V	0.25µA @ 5V	0.25µA @ 5V	0.25µA @ 5V	Not specified	0.25µA @ 5V	0.25µA @ 5V
Current - Quiescent (Max)	3mA	2mA	2.5mA	2mA	2.5mA	2.5mA	2.5mA	2.5mA
Operating Temperature	-55°C ~ 125°C	-40°C ~ 105°C	-25°C ~ 85°C	-40°C ~ 105°C	-40°C ~ 125°C	Not specified	-40°C ~ 125°C	0°C ~ 70°C
Package / Case	Die	14-TSSOP	14-SOIC	14-TSSOP	14-SOIC	14-SOIC	14-TSSOP	14-TSSOP
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Product Status	Active	Active	Active	Active	Active	Active	Active	Active

Engineering Selection Recommendations

Primary Substitutes (Highest Compatibility):

LM239DR2G (onsemi) and LM239PT (STMicroelectronics) provide direct functional equivalence to the LM139 MD8. Both devices maintain the 5mV input offset voltage specification, support the required supply voltage ranges, and operate across the full industrial temperature range. LM239DR2G offers the highest inventory availability (105,400 units) in 14-SOIC packaging. LM239PT provides equivalent performance in 14-TSSOP packaging with substantial stock (65,200 units).

Secondary Substitutes (Extended Temperature Range):

LM2901DT and LM2901VDTBR2G extend the upper operating temperature to 125°C, matching the LM139 MD8 specification. LM2901DT (STMicroelectronics, 185,200 units) in 14-SOIC and LM2901VDTBR2G (onsemi, 5,380 units) in 14-TSSOP both maintain quiescent current specifications within acceptable limits.

Automotive-Grade Option:

LM2901HYDT (STMicroelectronics) carries AEC-Q100 automotive qualification and Tape & Reel packaging. This variant supports extended supply voltage range (2V ~ 36V, ±1V ~ 18V) and maintains 2.5mA quiescent current specification. Suitable for applications requiring automotive-grade reliability.

Temperature-Limited Application:

LM339PT (STMicroelectronics) operates within 0°C ~ 70°C range and is not suitable for applications requiring full -55°C to 125°C coverage. This part is listed only for reference in applications with restricted temperature requirements.

Packaging Selection:

14-SOIC: Preferred for high-volume production and standard PCB assembly
14-TSSOP: Compact footprint alternative with equivalent electrical performance
16-QFN: Space-constrained applications (LM2901Q4T, LM339QT)

All recommended substitutes maintain ROHS3 compliance and Active product status, ensuring regulatory compliance and long-term availability.

Frequently Asked Questions (FAQ)

Q: Can LM139 MD8 die form be directly replaced with packaged alternatives?

A: Yes. The LM239 and LM2901 series in standard packages (14-SOIC, 14-TSSOP, 16-QFN) provide electrical equivalence to the LM139 MD8. Die-to-package conversion requires appropriate PCB layout and assembly process modifications, but functional performance remains identical when electrical specifications are matched.

Q: What is the primary difference between LM239 and LM2901 series?

A: Both series are quad general-purpose comparators with open-collector output. The LM2901 series typically offers extended supply voltage range (up to ±18V dual supply) and improved temperature coverage options. Selection depends on specific application voltage and temperature requirements.

Q: Is the 10mV hysteresis specification critical for substitution?

A: The LM139 MD8 specifies 10mV hysteresis. Most substitute parts do not explicitly specify hysteresis values in the provided data. Applications requiring precise hysteresis control should verify this parameter with the manufacturer datasheet before final selection.

Q: Which substitute offers the best inventory availability?

A: LM239DR2G (onsemi) provides the highest stock level at 105,400 units in 14-SOIC packaging. LM2901DT (STMicroelectronics) offers 185,200 units in 14-SOIC, making it the most readily available option across both manufacturers.

Q: Are there temperature range limitations with substitute parts?

A: LM339PT operates only within 0°C ~ 70°C and cannot replace the LM139 MD8 in applications requiring -55°C operation. LM239 series (APT, DR2G, PT variants) and LM2901 series (DT, HYDT, VDTBR2G) support extended temperature ranges compatible with the original specification.

Q: What packaging should be selected for new designs?

A: 14-SOIC and 14-TSSOP packages are industry-standard options with excellent availability and manufacturing support. 16-QFN packages (LM2901Q4T, LM339QT) are suitable for space-constrained applications. Die form (LM139 MD8) is typically reserved for hybrid circuit integration or specialized applications.

Q: Do all substitutes support the same supply voltage range?

A: No. The LM139 MD8 specifies 5V ~ 30V (single) or ±2.5V ~ ±15V (dual). Most substitutes support wider ranges: 2V ~ 32V or 3V ~ 36V (single) and ±1V ~ ±18V (dual). Verify that the selected substitute meets the minimum voltage requirement for your application.

Q: Is RoHS3 compliance maintained across all substitutes?

A: Yes. All listed substitute parts carry ROHS3 Compliant status, ensuring environmental and regulatory compliance equivalent to the LM139 MD8.

Q: Can LM2901HYDT be used in non-automotive applications?

A: Yes. LM2901HYDT carries AEC-Q100 automotive qualification but is functionally suitable for general industrial and commercial applications. The automotive qualification represents an additional quality assurance level and does not restrict use in other applications.

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