KA339A Equivalent & Substitute Parts

Part Overview

The KA339A is a general-purpose comparator IC manufactured by onsemi, featuring four independent comparators in a 14-pin DIP package. This device supports DTL, MOS, Open-Collector, and TTL output configurations with a supply voltage range of 2V to 36V (single) or ±1V to ±18V (dual). The KA339A is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support.

Substiute Parts

KA339A

onsemiIn Stock: 1363KA339A Datasheet

Current PartRFQ

LM339DR2G

onsemiIn Stock: 205270LM339DR2G Datasheet

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KA339A

Fairchild SemiconductorIn Stock: 1454KA339A Datasheet

Parametric EquivalentRFQ

LM339AN

Harris CorporationIn Stock: 15713LM339AN Datasheet

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LM339N

STMicroelectronicsIn Stock: 124922LM339N Datasheet

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LM339NE3

Texas InstrumentsIn Stock: 18050LM339NE3 Datasheet

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LM339NE4

Texas InstrumentsIn Stock: 1052LM339NE4 Datasheet

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Key Parameters

Substitute Part Grouping Explanation

Substitution of the KA339A is determined by the following critical parameters:

• Number of Elements: Must be 4 independent comparators
• Output Type: Must support Open-Collector configuration (minimum requirement for compatibility)
• Voltage - Supply Range: Must accommodate 2V ~ 36V single supply or ±1V ~ ±18V dual supply
• Voltage - Input Offset (Max): Must not exceed 5mV @ 5V or 30V
• Current - Input Bias (Max): Must not exceed 0.25µA @ 5V
• Current - Output (Typ): Must support minimum 16mA @ 5V
• Current - Quiescent (Max): Must not exceed 2.5mA
• Operating Temperature: Must support 0°C ~ 70°C range
• Package Compatibility: Through-hole 14-DIP packages are directly interchangeable; surface-mount alternatives (14-SOIC) require PCB redesign

Substitute parts are grouped into two categories: pin-compatible through-hole replacements and functionally equivalent surface-mount alternatives.

Parameter Comparison

Engineering Selection Recommendations

For Direct Pin-Compatible Replacement (Through-Hole 14-DIP):

LM339NE3 (Texas Instruments) is the preferred substitute. This device is currently active in production, ROHS3 compliant, and meets all electrical parameters of the KA339A. The LM339NE3 supports the required supply voltage range (2V ~ 30V single, ±1V ~ ±15V dual), input offset specifications, and output current requirements. Availability is confirmed at 17,975 units in stock.

LM339NE4 (Texas Instruments) is an alternative pin-compatible option, though it is discontinued at DiGi Electronics with limited inventory (974 units). This part is functionally equivalent to LM339NE3 but should be considered only when LM339NE3 is unavailable.

LM339N (STMicroelectronics) is a through-hole alternative with broader output type support (CMOS, DTL, ECL, MOS, Open-Collector, TTL). However, this part is obsolete. High inventory (124,829 units) may support legacy production requirements.

LM339AN (Harris Corporation) is a through-hole option with superior input offset performance (2mV @ 30V). This part is obsolete and RoHS non-compliant, limiting its use to non-regulated applications.

For Surface-Mount Replacement (14-SOIC):

LM339DR2G (onsemi) is the only surface-mount substitute provided. This device is active in production, ROHS3 compliant, and offers the highest inventory availability (205,200 units). The LM339DR2G meets all critical electrical parameters with a minimum supply voltage of 3V (versus 2V for the KA339A). PCB redesign is required for package conversion from 14-DIP to 14-SOIC.

Compliance Considerations:

All recommended active substitutes (LM339NE3, LM339DR2G) are ROHS3 compliant and REACH unaffected, meeting modern regulatory requirements. Obsolete alternatives should be evaluated only for legacy system maintenance where RoHS compliance is not mandated.

Frequently Asked Questions (FAQ)

Q: Can LM339DR2G replace KA339A without PCB modification?

A: No. LM339DR2G uses a 14-SOIC surface-mount package, while KA339A uses a 14-DIP through-hole package. PCB redesign is required. For direct socket replacement, use LM339NE3 or LM339N.

Q: What is the minimum supply voltage difference between KA339A and substitute parts?

A: KA339A supports 2V minimum single supply. LM339DR2G requires 3V minimum. LM339NE3, LM339NE4, LM339N, and LM339AN all support 2V minimum, matching the original specification.

Q: Are all substitute parts ROHS3 compliant?

A: LM339NE3, LM339NE4, LM339N, and LM339DR2G are ROHS3 compliant. LM339AN is RoHS non-compliant and should not be used in applications requiring RoHS certification.

Q: Which substitute has the best input offset performance?

A: LM339AN offers 2mV @ 30V input offset, matching the KA339A specification of 2mV @ 5V. However, this part is obsolete and RoHS non-compliant. LM339NE3 and LM339NE4 specify 5mV @ 30V, which is acceptable for most general-purpose comparator applications.

Q: What is the current availability status of recommended substitutes?

A: LM339NE3 (Texas Instruments) has 17,975 units in stock and is active in production. LM339DR2G (onsemi) has 205,200 units in stock and is active in production. Both are suitable for new designs and ongoing production.

Q: Can LM339N be used as a long-term substitute despite being obsolete?

A: LM339N is obsolete but has high inventory availability (124,829 units). It is suitable only for legacy production support or non-regulated applications. For new designs, LM339NE3 is the recommended choice.

Q: Are there output type differences that affect circuit compatibility?

A: All substitutes support Open-Collector output, which is the minimum requirement for KA339A compatibility. LM339N and LM339DR2G offer additional output types (CMOS, DTL, ECL, MOS, TTL), but these do not affect basic comparator functionality in standard applications.