KA337TU Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The KA337TU is a linear voltage regulator IC manufactured by onsemi, designed for negative adjustable output applications with 1.5A current capacity in TO-220-3 packaging. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. The KA337TU operates across an input voltage range of -40V maximum and provides adjustable output from -1.2V to -37V, with integrated over-temperature and short-circuit protection.

Key Parameters

Parameter	Value
Manufacturer	onsemi
Part Number	KA337TU
Category	Power Management (PMIC)
Output Configuration	Negative
Output Type	Adjustable
Current - Output	1.5A
Voltage - Input (Max)	-40V
Voltage - Output (Min/Fixed)	-1.2V
Voltage - Output (Max)	-37V
PSRR	60dB (120Hz)
Protection Features	Over Temperature, Short Circuit
Operating Temperature	0°C ~ 125°C
Package / Case	TO-220-3
Mounting Type	Through Hole
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution for the KA337TU is determined by strict alignment of the following electrical and mechanical parameters:

Critical Substitution Parameters:

Output Configuration: Negative
Output Type: Adjustable
Current - Output: 1.5A
Voltage - Input (Max): -40V
Voltage - Output Range: -1.2V to -37V
Package / Case: TO-220-3
Mounting Type: Through Hole

Substitute parts are grouped into two categories based on product status and availability:

Direct Manufacturer Substitutes (Active Status): Parts that maintain identical electrical specifications and packaging, sourced from onsemi or other manufacturers with active product status.

Parametric Equivalents (Active or Last Time Buy Status): Parts that meet all critical electrical parameters and packaging requirements but may have minor variations in PSRR, quiescent current, or protection feature details.

Parameter Comparison

Parameter	KA337TU	LM337BTG	LM337TG	LM337SP	LM337T/NOPB	LM337KCSE3	LM337T	LM337T/LF01
Manufacturer	onsemi	onsemi	onsemi	STMicroelectronics	Texas Instruments	Texas Instruments	onsemi	Texas Instruments
Output Configuration	Negative	Negative	Negative	Negative	Negative	Negative	Negative	Negative
Output Type	Adjustable	Adjustable	Adjustable	Adjustable	Adjustable	Adjustable	Adjustable	Adjustable
Current - Output	1.5A	1.5A	1.5A	1.5A	1.5A	1.5A	1.5A	1.5A
Voltage - Input (Max)	-40V	-40V	-40V	40V	-40V	-40V	-40V	-40V
Voltage - Output (Min/Fixed)	-1.2V	-1.2V	-1.2V	-1.2V	-1.2V	-1.2V	-1.2V	-1.2V
Voltage - Output (Max)	-37V	-37V	-37V	-37V	-37V	-37V	-37V	-37V
PSRR	60dB (120Hz)	77dB (120Hz)	77dB (120Hz)	77dB ~ 60dB (120Hz)	77dB (120Hz)	77dB (120Hz)	60dB (120Hz)	77dB (120Hz)
Protection Features	Over Temperature, Short Circuit	Over Current, Over Temperature	Over Current, Over Temperature	Over Current, Over Temperature	Over Temperature, Short Circuit	Over Temperature, Short Circuit	Over Temperature, Short Circuit	Over Temperature, Short Circuit
Operating Temperature	0°C ~ 125°C	-40°C ~ 125°C	0°C ~ 125°C	0°C ~ 125°C	0°C ~ 125°C	0°C ~ 125°C	0°C ~ 125°C	0°C ~ 125°C
Package / Case	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3	TO-220-3
Mounting Type	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Through Hole	Surface Mount
Product Status	Obsolete	Active	Active	Active	Active	Last Time Buy	Obsolete	Active
RoHS Status	Not Specified	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant	Not Specified	ROHS3 Compliant

Engineering Selection Recommendations

For Active Product Status Requirement:

LM337T/NOPB (Texas Instruments) and LM337T/LF01 (Texas Instruments) are recommended as primary substitutes. Both maintain active product status, ROHS3 compliance, and identical electrical specifications to the KA337TU. LM337T/NOPB provides standard through-hole mounting, while LM337T/LF01 offers formed leads for surface-mount applications.

LM337BTG (onsemi) and LM337TG (onsemi) are active alternatives with extended operating temperature range (-40°C to 125°C for LM337BTG) and improved PSRR (77dB). Both are ROHS3 compliant.

LM337SP (STMicroelectronics) is an active substitute with ROHS3 compliance and equivalent electrical performance, though input voltage specification differs in notation.

For Last Time Buy Consideration:

LM337KCSE3 (Texas Instruments) maintains Last Time Buy status with full electrical equivalence and ROHS3 compliance. This part is suitable for designs where long-term availability is not critical.

For Obsolete Status Avoidance:

LM337T (onsemi) shares obsolete status with the KA337TU and should not be selected for new designs requiring active product support.

Frequently Asked Questions (FAQ)

Q: Can LM337T/LF01 replace KA337TU in existing through-hole PCB designs?

A: LM337T/LF01 uses TO-220-3 packaging with formed leads designed for surface-mount applications. While the package designation is TO-220-3, the formed leads configuration differs from standard through-hole mounting. PCB redesign or adapter solutions are required for direct substitution in through-hole layouts.

Q: What is the difference between LM337BTG and LM337TG?

A: Both parts are onsemi LM337 variants with identical electrical specifications and ROHS3 compliance. The primary difference is operating temperature range: LM337BTG operates from -40°C to 125°C, while LM337TG operates from 0°C to 125°C. Select LM337BTG for applications requiring extended low-temperature performance.

Q: Is LM337SP from STMicroelectronics a direct replacement?

A: LM337SP meets all critical electrical parameters and packaging requirements. It is ROHS3 compliant and maintains active product status. The input voltage specification notation differs (40V vs. -40V), but this reflects documentation convention rather than functional difference for negative regulator operation.

Q: Why do some substitutes show higher PSRR than the KA337TU?

A: PSRR (Power Supply Rejection Ratio) improvements in newer variants (77dB vs. 60dB at 120Hz) represent enhanced performance characteristics. Higher PSRR provides better noise rejection and is functionally compatible with designs specified for the KA337TU's 60dB performance.

Q: Which substitute offers the best long-term availability?

A: LM337T/NOPB (Texas Instruments) and LM337TG (onsemi) both maintain active product status with high inventory levels (5242 and 25300 units respectively). Both are ROHS3 compliant and suitable for designs requiring sustained component availability.

Q: Can I use LM337KCSE3 in production designs?

A: LM337KCSE3 is classified as Last Time Buy, indicating limited future availability. While electrically equivalent and ROHS3 compliant, it is not recommended for new production designs. Use active-status alternatives such as LM337T/NOPB or LM337BTG instead.

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