LMS1587CS-1.5 Linear Voltage Regulator Equivalent & Substitute Parts

Part Overview

The LMS1587CS-1.5 is a linear voltage regulator IC from Texas Instruments designed for positive fixed 1.5V output at 3A current capacity in a TO-263 (DDPAK-3) surface mount package. This part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement. The device provides over-current and over-temperature protection suitable for power management applications requiring stable 1.5V regulation.

Key Parameters

Parameter	Value
Output Voltage (Fixed)	1.5V
Output Current	3A
Input Voltage (Max)	13V
Voltage Dropout (Max)	1.3V @ 3A
Quiescent Current	7 mA
PSRR	60 ~ 72 dB (120Hz)
Protection Features	Over Current, Over Temperature
Operating Temperature	0°C ~ 125°C
Package	TO-263 (DDPAK-3)
Mounting Type	Surface Mount

Substitute Part Grouping Explanation

Substitute parts for the LMS1587CS-1.5 are selected based on strict electrical and mechanical parameter matching. The critical substitution criteria are:

Fixed output voltage of 1.5V
Output current capability of 3A or greater
Maximum input voltage of 7V or higher
Voltage dropout specification of 1.3V @ 3A or lower
TO-263 (DDPAK-3) package compatibility
Surface mount configuration
Operating temperature range of 0°C to 125°C or wider
Over-current and over-temperature protection

Parts are grouped into two categories: direct equivalents with identical electrical specifications and alternative regulators with compatible but differing output current ratings.

Parameter Comparison

Part Number	Manufacturer	Output Voltage	Output Current	Input Voltage (Max)	Dropout @ Rated Current	Quiescent Current	PSRR (120Hz)	Package	Product Status
LMS1587CS-1.5	Texas Instruments	1.5V	3A	13V	1.3V @ 3A	7 mA	60 ~ 72 dB	TO-263 (DDPAK-3)	Obsolete
LMS1587CS-1.5/NOPB	National Semiconductor	1.5V	3A	13V	1.3V @ 3A	7 mA	60 ~ 72 dB	TO-263 (DDPAK-3)	Active
LT1587CM-1.5#PBF	Analog Devices Inc.	1.5V	3A	7V	1.3V @ 3A	—	72 dB	TO-263 (DDPAK-3)	Active
LT1587CM-1.5#TRPBF	Analog Devices Inc.	1.5V	3A	7V	1.3V @ 3A	—	72 dB	TO-263 (DDPAK-3)	Active
RT9164A-15GM	Richtek USA Inc.	1.5V	1A	14V	1.4V @ 1A	10 mA	72 dB	TO-263-3	Active

Engineering Selection Recommendations

For direct replacement of the obsolete LMS1587CS-1.5, the LMS1587CS-1.5/NOPB from National Semiconductor is the primary equivalent, offering identical electrical specifications and active product status with bulk packaging availability.

The LT1587CM-1.5#PBF and LT1587CM-1.5#TRPBF from Analog Devices Inc. are functionally equivalent alternatives with active status and ROHS3 compliance. These parts differ in maximum input voltage (7V versus 13V) and packaging format (tube or tape & reel). The LT1587CM variants provide improved PSRR performance at 72 dB and enhanced moisture sensitivity rating (MSL 1 versus MSL 3).

The RT9164A-15GM from Richtek USA Inc. is a compatible alternative with extended operating temperature range (-40°C to 125°C) and higher maximum input voltage (14V). However, this part is rated for 1A output current, making it unsuitable for applications requiring the full 3A capacity of the original LMS1587CS-1.5.

Selection should prioritize LMS1587CS-1.5/NOPB for direct substitution or LT1587CM variants for designs requiring improved compliance and moisture sensitivity performance.

Frequently Asked Questions (FAQ)

Q: Can the LT1587CM-1.5 variants be used as direct replacements for the LMS1587CS-1.5?

A: Yes, the LT1587CM-1.5#PBF and LT1587CM-1.5#TRPBF are functionally equivalent for applications operating within 7V maximum input voltage. Both maintain 1.5V fixed output, 3A current capacity, and TO-263 package compatibility. The primary difference is packaging format: tube versus tape & reel.

Q: What is the significance of the maximum input voltage difference between LMS1587CS-1.5 (13V) and LT1587CM-1.5 (7V)?

A: The input voltage rating determines the maximum voltage that can be safely applied to the regulator. Designs operating above 7V input require the LMS1587CS-1.5/NOPB or RT9164A-15GM. Designs with input voltages below 7V can use either part without limitation.

Q: Is the RT9164A-15GM suitable as a substitute for the LMS1587CS-1.5?

A: The RT9164A-15GM is compatible only for applications requiring 1A or less output current. The original LMS1587CS-1.5 is rated for 3A, and the RT9164A-15GM cannot deliver this current level. Use this part only when current requirements are 1A or lower.

Q: What packaging options are available for the LT1587CM-1.5?

A: The LT1587CM-1.5 is available in two packaging formats: LT1587CM-1.5#PBF (tube packaging) and LT1587CM-1.5#TRPBF (tape & reel packaging). Both use identical TO-263 (DDPAK-3) component packages with different quantity and handling formats.

Q: Are there RoHS compliance differences between substitute parts?

A: Yes. The LMS1587CS-1.5 is RoHS non-compliant. The LT1587CM-1.5 variants are ROHS3 compliant, and the RT9164A-15GM is ROHS3 compliant. Designs requiring RoHS compliance should specify LT1587CM or RT9164A alternatives.

Q: What is the moisture sensitivity level (MSL) difference, and does it matter?

A: The LMS1587CS-1.5 and RT9164A-15GM have MSL 3 (168 hours), while LT1587CM variants have MSL 1 (unlimited). MSL 1 parts have superior moisture resistance and longer shelf life without special storage conditions. For high-reliability applications or extended storage, LT1587CM variants are preferred.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message