MIC5239-5.0BS Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The MIC5239-5.0BS is a linear voltage regulator IC from Microchip Technology designed for positive fixed 5V output applications with 500mA current capacity in SOT-223-3 surface mount packaging. This part is classified as obsolete, making equivalent and substitute parts necessary for new designs and ongoing production support. The MIC5239-5.0BS provides regulated 5V output with integrated protection features including over-current, over-temperature, over-voltage, and reverse polarity protection, suitable for low-power embedded systems and industrial applications requiring compact form factors.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	5V
Output Current	500mA
Input Voltage (Max)	30V
Voltage Dropout (Max)	0.35V @ 500mA (Typ)
Quiescent Current	45 µA
Operating Temperature Range	-40°C ~ 125°C
Package Type	SOT-223-3
Protection Features	Over Current, Over Temperature, Over Voltage, Reverse Polarity
Control Features	Enable
RoHS Status	RoHS non-compliant

Substitute Part Grouping Explanation

Substitution for the MIC5239-5.0BS is determined by the following critical parameters: fixed 5V output voltage, minimum 500mA output current capability, maximum input voltage of 26V or higher, surface mount packaging compatibility (SOT-223-3 or SOT-223-4), and operating temperature range of -40°C to 85°C or better. Parts are grouped into two categories based on output current capacity and packaging variants:

Category 1: Direct Microchip Equivalents (Same Manufacturer, Active Status)

MIC5239-5.0YS and MIC5239-5.0YS-TR maintain identical electrical specifications with improved RoHS3 compliance and active product status

Category 2: Cross-Manufacturer Substitutes (Texas Instruments & MaxLinear)

LM2937 series (LM2937IMP-5.0/NOPB, LM2937IMPX-5.0/NOPB): 500mA output, 26V max input, SOT-223-4 package
LM2940 series (LM2940IMP-5.0/NOPB, LM2940IMPX-5.0/NOPB): 1A output (higher capacity), 26V max input, SOT-223-4 package
SPX2954 series (SPX2954M3-L-5-0/TR, SPX2954AM3-L-5-0/TR): 250mA output (lower capacity), 30V max input, SOT-223-3 package

Parameter Comparison

Part Number	Manufacturer	Output Current	Input Voltage (Max)	Voltage Dropout (Max)	Package	Operating Temp	Product Status	RoHS Status
MIC5239-5.0BS	Microchip Technology	500mA	30V	0.35V @ 500mA	SOT-223-3	-40°C ~ 125°C	Obsolete	RoHS non-compliant
MIC5239-5.0YS	Microchip Technology	500mA	30V	0.35V @ 500mA	SOT-223-3	-40°C ~ 125°C	Active	ROHS3 Compliant
MIC5239-5.0YS-TR	Microchip Technology	500mA	30V	0.35V @ 500mA	SOT-223-3	-40°C ~ 125°C	Active	ROHS3 Compliant
LM2937IMP-5.0/NOPB	Texas Instruments	500mA	26V	1V @ 500mA	SOT-223-4	-40°C ~ 85°C	Active	ROHS3 Compliant
LM2937IMPX-5.0/NOPB	Texas Instruments	500mA	26V	1V @ 500mA	SOT-223-4	-40°C ~ 85°C	Active	ROHS3 Compliant
LM2940IMP-5.0/NOPB	Texas Instruments	1A	26V	1V @ 1A	SOT-223-4	-40°C ~ 85°C	Active	ROHS3 Compliant
LM2940IMPX-5.0/NOPB	Texas Instruments	1A	26V	1V @ 1A	SOT-223-4	-40°C ~ 85°C	Active	ROHS3 Compliant
SPX2954M3-L-5-0/TR	MaxLinear, Inc.	250mA	30V	0.5V @ 250mA	SOT-223-3	-40°C ~ 125°C	Active	RoHS Compliant
SPX2954AM3-L-5-0/TR	MaxLinear, Inc.	250mA	30V	0.5V @ 250mA	SOT-223-3	-40°C ~ 125°C	Active	RoHS Compliant

Engineering Selection Recommendations

Primary Recommendation: MIC5239-5.0YS or MIC5239-5.0YS-TR These Microchip parts provide direct electrical equivalence to the MIC5239-5.0BS with identical output current (500mA), input voltage rating (30V), and thermal performance (-40°C to 125°C). Both variants are in active production status with ROHS3 compliance, addressing the obsolescence of the original part. The -TR variant uses Cut Tape & Digi-Reel packaging suitable for automated assembly, while the standard -YS variant uses Tube packaging. No design modifications are required for PCB layout or thermal management.

Secondary Recommendation: LM2937IMP-5.0/NOPB or LM2937IMPX-5.0/NOPB Texas Instruments LM2937 series maintains 500mA output current matching the original specification. These parts feature SOT-223-4 packaging (4-pin versus 3-pin) and reduced maximum input voltage (26V versus 30V). Operating temperature range is limited to -40°C to 85°C. These substitutes are suitable for applications where input voltage does not exceed 26V and the extended temperature range above 85°C is not required. PCB layout modifications are necessary due to package pin count change.

Upgrade Option: LM2940IMP-5.0/NOPB or LM2940IMPX-5.0/NOPB The LM2940 series provides 1A output current, doubling the capacity of the original MIC5239-5.0BS. This option is suitable for designs requiring higher current delivery or future current margin. Like the LM2937 series, these parts use SOT-223-4 packaging and operate to 85°C maximum. ROHS3 compliance and active production status are confirmed.

Lower-Current Alternative: SPX2954M3-L-5-0/TR or SPX2954AM3-L-5-0/TR MaxLinear SPX2954 series maintains SOT-223-3 packaging and 30V input voltage rating with extended temperature range (-40°C to 125°C). Output current is limited to 250mA, making these parts suitable only for applications where load current does not exceed 250mA. Both variants are RoHS compliant and in active production. No PCB layout changes are required due to identical package type.

Frequently Asked Questions (FAQ)

Q: Can I use MIC5239-5.0YS as a direct replacement for MIC5239-5.0BS without PCB modifications? A: Yes. The MIC5239-5.0YS maintains identical SOT-223-3 packaging, pin configuration, and electrical specifications. No PCB layout changes are required. The primary difference is improved RoHS3 compliance and active product status.

Q: What is the difference between MIC5239-5.0YS and MIC5239-5.0YS-TR? A: Both parts have identical electrical specifications and packaging type (SOT-223-3). The difference is in supply format: MIC5239-5.0YS uses Tube packaging for manual handling, while MIC5239-5.0YS-TR uses Cut Tape & Digi-Reel format optimized for automated pick-and-place assembly equipment.

Q: Why do the LM2937 and LM2940 parts use SOT-223-4 packaging instead of SOT-223-3? A: The additional pin in SOT-223-4 provides a separate ground connection for improved thermal performance and noise isolation. This requires PCB layout modifications to accommodate the fourth pin and associated trace routing.

Q: Can I use SPX2954M3-L-5-0/TR if my application requires 500mA output? A: No. The SPX2954 series is rated for maximum 250mA output current. Using this part in a 500mA application will exceed the device rating and trigger over-current protection or cause thermal shutdown. Use MIC5239-5.0YS or LM2937 series for 500mA applications.

Q: What is the impact of the 1V dropout voltage in LM2937 and LM2940 compared to 0.35V in MIC5239-5.0BS? A: Higher dropout voltage requires greater input voltage headroom to maintain regulated 5V output. For example, with 1V dropout at full load, minimum input voltage must be 6V. Applications with input voltages between 5.35V and 6V will not function properly with LM2937/LM2940 substitutes. Verify input voltage specifications before selection.

Q: Are all substitute parts RoHS compliant? A: MIC5239-5.0YS, MIC5239-5.0YS-TR, LM2937 series, and LM2940 series are ROHS3 compliant. SPX2954 series is RoHS compliant. The original MIC5239-5.0BS is RoHS non-compliant. Verify compliance requirements for your application and supply chain.

Q: What is the operating temperature difference between MIC5239-5.0YS and LM2937? A: MIC5239-5.0YS operates from -40°C to 125°C, while LM2937 operates from -40°C to 85°C. Applications requiring operation above 85°C must use MIC5239-5.0YS or SPX2954 series. Verify thermal requirements for your end application.

Q: Can I substitute LM2940 (1A) for MIC5239-5.0BS (500mA) in existing designs? A: Yes, electrically and mechanically. The LM2940 provides higher current capacity and is backward compatible. However, PCB layout modifications are required due to SOT-223-4 packaging. Verify that input voltage does not exceed 26V and that operating temperature requirements do not exceed 85°C.

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