LP3855EMP-1.8 Equivalent & Substitute Parts

Part Overview

The LP3855EMP-1.8 is a linear voltage regulator IC manufactured by Texas Instruments, delivering a fixed 1.8V output at 1.5A in a SOT-223-5 surface mount package. This device is classified as obsolete, which necessitates identification of active equivalent alternatives for new designs and ongoing production requirements. The regulator incorporates enable control, over-current protection, over-temperature protection, and short-circuit protection, making it suitable for low-voltage power management applications requiring stable 1.8V rails.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Output Voltage (Fixed)	1.8V
Output Current	1.5A
Input Voltage (Max)	7V
Voltage Dropout (Max)	0.43V @ 1.5A
Quiescent Current (Iq)	3 mA
Package	SOT-223-5
Operating Temperature Range	-40°C to 125°C
Protection Features	Over Current, Over Temperature, Short Circuit
Control Features	Enable
Product Status	Obsolete

Substitute Part Grouping Explanation

Substitution eligibility for the LP3855EMP-1.8 is determined by the following critical parameters:

Output voltage fixed at 1.8V
Output current capability of 1.5A
Maximum input voltage of 7V
SOT-223-5 package compatibility
Enable control feature
Protection features: Over Current, Over Temperature, Short Circuit
Operating temperature range: -40°C to 125°C

Substitute parts are grouped into two categories based on voltage dropout characteristics:

Group 1 (Lower Dropout): LP3852EMP-1.8, LP3852EMP-1.8/NOPB, LP3852EMPX-1.8/NOPB, and LP3855EMP-1.8/NOPB feature a maximum dropout voltage of 0.43V @ 1.5A with quiescent current of 3 mA. These provide direct electrical equivalence to the main part.

Group 2 (Higher Dropout): LP3872EMP-1.8/NOPB, LP3875EMP-1.8/NOPB, LP3962EMP-1.8/NOPB, and LP3965EMP-1.8/NOPB feature a maximum dropout voltage of 0.55V @ 1.5A with quiescent current of 5-9 mA. These are functionally equivalent but with relaxed dropout specifications.

Parameter Comparison

Part Number	Manufacturer	Output Voltage	Output Current	Dropout (Max)	Iq (mA)	Package	Product Status	RoHS Status
LP3855EMP-1.8	Texas Instruments	1.8V	1.5A	0.43V @ 1.5A	3	SOT-223-5	Obsolete	Non-compliant
LP3852EMP-1.8	Texas Instruments	1.8V	1.5A	0.43V @ 1.5A	3	SOT-223-5	Last Time Buy	ROHS3 Compliant
LP3852EMP-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.43V @ 1.5A	3	SOT-223-5	Active	ROHS3 Compliant
LP3852EMPX-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.43V @ 1.5A	3	SOT-223-5	Active	ROHS3 Compliant
LP3855EMP-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.43V @ 1.5A	3	SOT-223-5	Active	ROHS3 Compliant
LP3872EMP-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.55V @ 1.5A	5	SOT-223-5	Active	ROHS3 Compliant
LP3875EMP-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.55V @ 1.5A	5	SOT-223-5	Active	ROHS3 Compliant
LP3962EMP-1.8/NOPB	National Semiconductor	1.8V	1.5A	0.55V @ 1.5A	9	SOT-223	Active	Not specified
LP3965EMP-1.8/NOPB	Texas Instruments	1.8V	1.5A	0.55V @ 1.5A	9	SOT-223-5	Active	ROHS3 Compliant

Engineering Selection Recommendations

For new designs and production transitions, LP3852EMP-1.8/NOPB or LP3855EMP-1.8/NOPB are the primary recommendations. Both parts maintain the 0.43V maximum dropout specification of the original LP3855EMP-1.8, are ROHS3 compliant, and carry Active product status, ensuring long-term availability and supply chain stability.

LP3852EMPX-1.8/NOPB provides an alternative with identical electrical specifications and Active status, suitable where extended temperature or specialized screening is required.

For applications where the increased dropout voltage of 0.55V is acceptable, LP3872EMP-1.8/NOPB, LP3875EMP-1.8/NOPB, and LP3965EMP-1.8/NOPB offer Active status with ROHS3 compliance. These parts feature higher quiescent current (5-9 mA) and should be evaluated for thermal and power budget impact.

LP3962EMP-1.8/NOPB, manufactured by National Semiconductor, is electrically equivalent but sourced from a different manufacturer. Compliance certifications are not fully specified for this part.

Frequently Asked Questions (FAQ)

Q: Can LP3852EMP-1.8/NOPB directly replace LP3855EMP-1.8 in existing designs?

A: Yes. Both parts share identical electrical specifications: 1.8V fixed output, 1.5A current capability, 0.43V maximum dropout at 1.5A, 3 mA quiescent current, and SOT-223-5 packaging. The primary difference is product status and RoHS compliance. LP3852EMP-1.8/NOPB is Active and ROHS3 compliant, whereas LP3855EMP-1.8 is Obsolete and non-compliant.

Q: What is the difference between LP3852EMP-1.8 and LP3852EMP-1.8/NOPB?

A: The /NOPB suffix indicates halogen-free, lead-free packaging. Both parts are electrically identical. LP3852EMP-1.8 carries Last Time Buy status, while LP3852EMP-1.8/NOPB is Active. For new designs, LP3852EMP-1.8/NOPB is preferred.

Q: Can I use LP3872EMP-1.8/NOPB or LP3965EMP-1.8/NOPB as substitutes?

A: These parts are functionally equivalent but feature higher dropout voltage (0.55V vs. 0.43V) and higher quiescent current (5-9 mA vs. 3 mA). They are suitable substitutes only if the application can tolerate increased dropout voltage and power dissipation. Verify thermal performance in your specific circuit.

Q: Are all substitute parts available in SOT-223-5 packaging?

A: All recommended substitutes except LP3962EMP-1.8/NOPB are packaged in SOT-223-5. LP3962EMP-1.8/NOPB uses SOT-223 packaging, which is mechanically compatible but sourced from National Semiconductor rather than Texas Instruments.

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

A: LP3852EMP-1.8/NOPB, LP3855EMP-1.8/NOPB, LP3872EMP-1.8/NOPB, LP3875EMP-1.8/NOPB, and LP3965EMP-1.8/NOPB all carry Active product status, indicating ongoing production and supply commitment. These are preferred over Last Time Buy or Obsolete designations.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message