LP38691SDX-5.0 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LP38691SDX-5.0 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 5V output applications with 500mA current capacity in a 6-WSON (3x3) surface mount package. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing production and design updates. The part is qualified to AEC-Q100 automotive standards and operates across the -40°C to 125°C temperature range with integrated over-temperature protection.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	5V
Output Current	500mA
Input Voltage (Max)	10V
Voltage Dropout (Max)	0.45V @ 500mA
Quiescent Current (Iq)	55 µA
PSRR	55dB (120Hz)
Operating Temperature Range	-40°C ~ 125°C
Package	6-WDFN Exposed Pad / 6-WSON (3x3)
Grade	Automotive
Qualification	AEC-Q100

Substitute Part Grouping Explanation

Substitution eligibility for the LP38691SDX-5.0 is determined by strict equivalence across the following critical parameters:

Output voltage: 5V fixed
Output current capacity: 500mA
Input voltage maximum: 10V
Voltage dropout: 0.45V @ 500mA
Quiescent current: 55 µA
PSRR: 55dB (120Hz)
Operating temperature range: -40°C ~ 125°C
Package type: 6-WDFN Exposed Pad / 6-WSON (3x3)
Automotive grade and AEC-Q100 qualification

All identified substitute parts maintain identical electrical specifications and package configuration. Differences exist only in product status (active vs. obsolete), RoHS compliance status, and packaging format (bulk, tape & reel, or unspecified).

Parameter Comparison

Part Number	Manufacturer	Product Status	Output Voltage	Output Current	Voltage Dropout	Operating Temp	RoHS Status	Packaging	Inventory (Pcs)
LP38691SDX-5.0	Texas Instruments	Obsolete	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	RoHS non-compliant	Unspecified	4430
LP38691SDX-5.0/NOPB	Texas Instruments	Active	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	ROHS3 Compliant	Unspecified	4800
LP38691QSD-5.0/NOPB	Texas Instruments	Active	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	ROHS3 Compliant	Tape & Reel (TR)	1932
LP38691QSDX-5.0/NOPB	National Semiconductor	Active	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	Not specified	Bulk	87622
LP38691SD-5.0/NOPB	Texas Instruments	Active	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	ROHS3 Compliant	Tape & Reel (TR)	7100
LP38693SDX-5.0/NOPB	Texas Instruments	Active	5V	500mA	0.45V @ 500mA	-40°C ~ 125°C	ROHS3 Compliant	Unspecified	7700

Engineering Selection Recommendations

For applications requiring the LP38691SDX-5.0, the following selection criteria apply:

Active Product Status Priority: LP38691SDX-5.0/NOPB, LP38691QSD-5.0/NOPB, LP38691QSDX-5.0/NOPB, LP38691SD-5.0/NOPB, and LP38693SDX-5.0/NOPB are all active products and are preferred over the obsolete original part number.

RoHS Compliance: Texas Instruments variants (LP38691SDX-5.0/NOPB, LP38691QSD-5.0/NOPB, LP38691SD-5.0/NOPB, LP38693SDX-5.0/NOPB) are ROHS3 compliant. The National Semiconductor variant (LP38691QSDX-5.0/NOPB) does not specify RoHS status.

Packaging Format: Selection between bulk, tape & reel, or unspecified packaging depends on production volume and assembly requirements. Tape & reel formats (LP38691QSD-5.0/NOPB, LP38691SD-5.0/NOPB) are suitable for automated assembly processes. Bulk packaging (LP38691QSDX-5.0/NOPB) supports high-volume applications.

Inventory Availability: LP38691QSDX-5.0/NOPB offers the highest inventory level at 87,622 pieces. LP38693SDX-5.0/NOPB provides 7,700 pieces, and LP38691SD-5.0/NOPB provides 7,100 pieces.

Automotive Qualification: All substitute parts maintain AEC-Q100 qualification and automotive-grade classification, ensuring compatibility with automotive applications.

Frequently Asked Questions (FAQ)

Q: Can LP38691SDX-5.0/NOPB directly replace the obsolete LP38691SDX-5.0?

A: Yes. LP38691SDX-5.0/NOPB is electrically and mechanically identical to the original part. The primary difference is active product status and ROHS3 compliance. The "/NOPB" suffix indicates lead-free solder ball construction.

Q: What is the difference between LP38691QSD-5.0/NOPB and LP38691SD-5.0/NOPB?

A: Both parts are electrically identical with identical electrical specifications. The difference lies in packaging format: LP38691QSD-5.0/NOPB is supplied in tape & reel format, while LP38691SD-5.0/NOPB is also supplied in tape & reel format. Selection depends on assembly equipment compatibility and production volume requirements.

Q: Is LP38691QSDX-5.0/NOPB from National Semiconductor compatible with Texas Instruments designs?

A: Yes. LP38691QSDX-5.0/NOPB maintains identical electrical specifications, output voltage, current capacity, dropout voltage, and operating temperature range. It is qualified to AEC-Q100 automotive standards. Compatibility is confirmed at the electrical and mechanical interface level.

Q: Why is LP38693SDX-5.0/NOPB listed as a substitute?

A: LP38693SDX-5.0/NOPB maintains all critical electrical parameters identical to LP38691SDX-5.0, including 5V output, 500mA current capacity, 0.45V dropout voltage, and AEC-Q100 qualification. The base product number differs (LP38693 vs. LP38691), but functional equivalence is confirmed across all specified parameters.

Q: What packaging formats are available for these substitute parts?

A: Available packaging formats include tape & reel (TR) for LP38691QSD-5.0/NOPB and LP38691SD-5.0/NOPB, bulk for LP38691QSDX-5.0/NOPB, and unspecified format for LP38691SDX-5.0/NOPB, LP38693SDX-5.0/NOPB, and the original LP38691SDX-5.0. Tape & reel format is standard for automated surface mount assembly. Bulk format supports manual or semi-automated processes.

Q: Are all substitute parts RoHS compliant?

A: Texas Instruments variants (LP38691SDX-5.0/NOPB, LP38691QSD-5.0/NOPB, LP38691SD-5.0/NOPB, LP38693SDX-5.0/NOPB) are ROHS3 compliant. The National Semiconductor variant (LP38691QSDX-5.0/NOPB) does not specify RoHS status in the provided data.

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