KA324A Equivalent & Substitute Parts

Part Overview

The KA324A is a general-purpose operational amplifier integrated circuit containing four independent amplifier circuits in a 14-pin DIP package. Manufactured by onsemi, this device is classified as obsolete and is no longer in active production. The KA324A operates across a wide supply voltage range of 3V to 32V and is suitable for general-purpose amplification applications requiring moderate performance specifications.

Due to its obsolete status, locating new original stock of the KA324A presents supply chain challenges. Identifying equivalent and substitute parts with compatible electrical and mechanical characteristics is necessary to maintain design continuity and ensure project feasibility. Substitute parts must maintain compatibility with the original 14-DIP through-hole mounting configuration and deliver equivalent performance within the specified operating parameters.

Key Parameters

Parameter	KA324A Value	Unit
Amplifier Type	General Purpose	—
Number of Circuits	4	—
Current - Input Bias	40	nA
Voltage - Input Offset	1.5	mV
Current - Supply	1.5	mA
Current - Output / Channel	40	mA
Voltage - Supply Span (Min)	3	V
Voltage - Supply Span (Max)	32	V
Operating Temperature	0 to 70	°C
Mounting Type	Through Hole	—
Package / Case	14-DIP (0.300", 7.62mm)	—
Product Status	Obsolete	—
RoHS Status	ROHS3 Compliant	—

Substitute Part Grouping Explanation

Substitution of the KA324A is determined by strict alignment of electrical and mechanical parameters. The following criteria establish valid substitute relationships:

Primary Substitution Criteria:

Amplifier Type: General Purpose (matching the KA324A classification)
Number of Circuits: 4 (quad configuration)
Mounting Type: Through Hole (mechanical compatibility)
Package / Case: 14-DIP (0.300", 7.62mm) (physical interchangeability)
Current - Input Bias: ≤ 40 nA (equal or lower bias current)
Voltage - Input Offset: ≤ 1.5 mV (equal or lower offset voltage)
Current - Supply: ≤ 1.5 mA (equal or lower supply current)
Current - Output / Channel: ≥ 40 mA (equal or greater output capability)
Voltage - Supply Span (Min): ≤ 3 V (equal or lower minimum supply)
Voltage - Supply Span (Max): ≥ 32 V (equal or greater maximum supply)
Operating Temperature: 0°C to 70°C minimum coverage

Substitute parts meeting all primary criteria are classified as direct replacements. Parts with deviations in electrical performance or operating temperature range are identified with specific parameter differences for engineering evaluation.

Parameter Comparison

Part Number	Manufacturer	Amplifier Type	Number of Circuits	Current - Input Bias (nA)	Voltage - Input Offset (mV)	Current - Supply (mA)	Current - Output / Channel (mA)	Voltage - Supply Min (V)	Voltage - Supply Max (V)	Operating Temp (°C)	Package	Product Status
KA324A	onsemi	General Purpose	4	40	1.5	1.5	40	3	32	0 to 70	14-DIP	Obsolete
LM324ADR2G	onsemi	General Purpose	4	40	2	1.5	40	3	32	0 to 70	14-SOIC	Active
LM224N	STMicroelectronics	General Purpose	4	20	2	1.5	40	3	30	-40 to 105	14-DIP	Obsolete
LM248N	STMicroelectronics	General Purpose	4	30	1	2.1	25	44	44	-40 to 105	14-DIP	Obsolete
LM2900N	Texas Instruments	General Purpose	4	30	—	6.2	18	4.4	32	-40 to 85	14-DIP	Last Time Buy
LM2902N	STMicroelectronics	General Purpose	4	20	2	1.5	40	3	30	-40 to 125	14-DIP	Obsolete
LF347BN	onsemi	J-FET	4	0.05	3	7.2	40	36	36	0 to 70	14-DIP	Obsolete
LF347N	STMicroelectronics	J-FET	4	0.02	3	1.4	40	44	44	0 to 70	14-DIP	Obsolete
LF347N/NOPB	Texas Instruments	J-FET	4	0.05	5	7.2	40	36	36	0 to 70	14-DIP	Active
LF444ACN/NOPB	Texas Instruments	J-FET	4	0.01	2	0.6	14	44	44	0 to 70	14-DIP	Active
LF444CN/NOPB	Texas Instruments	J-FET	4	0.01	3	0.6	14	36	36	0 to 70	14-DIP	Active

Engineering Selection Recommendations

Direct Substitutes (14-DIP Through-Hole Package):

The LM224N and LM2902N are general-purpose quad operational amplifiers in 14-DIP through-hole packages with electrical parameters closely aligned to the KA324A. Both devices maintain the four-circuit configuration, 40 mA output current per channel, and 3V minimum supply voltage. The LM224N provides extended operating temperature range (-40°C to 105°C) and lower input bias current (20 nA). The LM2902N offers push-pull output configuration and extended upper operating temperature (125°C). Both are RoHS3 compliant and REACH unaffected.

Alternative General-Purpose Substitute (Surface Mount):

The LM324ADR2G is an active-status general-purpose quad amplifier from onsemi with identical electrical specifications to the KA324A. This device is available in 14-SOIC surface-mount package rather than through-hole DIP. Selection of this part requires PCB redesign to accommodate surface-mount technology.

J-FET Alternatives (Enhanced Performance):

The LF347N/NOPB (Texas Instruments, Active) and LF444CN/NOPB (Texas Instruments, Active) are J-FET input operational amplifiers offering significantly lower input bias current (50 pA and 10 pA respectively) compared to the KA324A (40 nA). These devices are suitable for applications requiring ultra-low input bias current. The LF347N/NOPB maintains 40 mA output current per channel and operates across 36V supply span. The LF444CN/NOPB provides the lowest input bias current but delivers reduced output current (14 mA per channel) and operates at 36V supply span.

Product Status Considerations:

The LM324ADR2G, LF347N/NOPB, and LF444CN/NOPB maintain active product status with ongoing manufacturer support and availability. The LM224N, LM248N, LM2902N, and LF347BN are obsolete or last-time-buy status, presenting long-term supply risk equivalent to the KA324A.

Frequently Asked Questions (FAQ)

Q: Can the LM324ADR2G directly replace the KA324A in existing PCB designs?

A: The LM324ADR2G is electrically compatible with the KA324A but uses 14-SOIC surface-mount packaging instead of 14-DIP through-hole. Direct PCB substitution is not possible without redesign. The device is suitable for new designs or PCB rework incorporating surface-mount footprints.

Q: What is the primary difference between general-purpose and J-FET amplifier types?

A: General-purpose amplifiers (KA324A, LM224N, LM2902N) use bipolar input stages with input bias currents in the nanoampere range (20-40 nA). J-FET amplifiers (LF347N/NOPB, LF444CN/NOPB) use field-effect transistor input stages with input bias currents in the picoampere range (10-50 pA). J-FET devices are selected for applications requiring minimal input bias current and high input impedance.

Q: Are all substitute parts RoHS3 compliant?

A: All substitute parts listed in this reference are RoHS3 compliant except LF347BN, which is RoHS non-compliant. Compliance verification is required for applications subject to RoHS regulations.

Q: What is the significance of operating temperature range differences?

A: The KA324A operates from 0°C to 70°C. The LM224N and LM2902N extend this range to -40°C to 105°C and -40°C to 125°C respectively. Extended temperature range devices are required for industrial and automotive applications. Standard-range devices (0°C to 70°C) are suitable for commercial and consumer applications.

Q: Can the LM2900N substitute for the KA324A?

A: The LM2900N is a general-purpose quad amplifier with four circuits and 40 mA output current per channel. However, it exhibits higher supply current (6.2 mA versus 1.5 mA) and lower output current per channel (18 mA versus 40 mA). The device is classified as Last Time Buy status, indicating discontinued production. Substitution is not recommended for new designs.

Q: What output current capability is required for substitute selection?

A: The KA324A delivers 40 mA per channel. Substitute parts must provide equal or greater output current capability. The LF444CN/NOPB and LF444ACN/NOPB deliver only 14 mA per channel and are suitable only for applications with reduced output current requirements.

Q: How do supply voltage ranges affect substitution decisions?

A: The KA324A operates across 3V to 32V supply span. Substitute parts must support this range or a superset of it. The LM224N and LM2902N support 3V to 30V, which is slightly narrower at the maximum. The LF347 and LF444 series require ±18V (36V span) or ±22V (44V span) dual supplies, making them unsuitable for single-supply applications.

Q: Is the LM248N a suitable substitute?

A: The LM248N is a general-purpose quad amplifier in 14-DIP package with lower output current per channel (25 mA versus 40 mA) and higher supply current (2.1 mA versus 1.5 mA). The device requires ±22V dual supply (44V span) rather than single supply operation. Substitution is not recommended for applications requiring 40 mA output current or single-supply operation.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message