LP3943ISQ/NOPB Equivalent & Substitute Parts

Part Overview

The LP3943ISQ/NOPB is an LED Driver IC manufactured by Texas Instruments, classified as a Power Management (PMIC) component. This 16-output power switch with I2C/SMBus dimming control operates across a 2.3V to 5.5V supply range and delivers 25mA per channel output. The device is housed in a 24-WQFN (4x4) package with exposed pad and is actively produced. Alternative components become necessary when addressing specific application constraints such as output channel requirements, packaging preferences, or supply chain availability.

Key Parameters

Parameter	Value
Manufacturer Part Number	LP3943ISQ/NOPB
Manufacturer	Texas Instruments
Category	Power Management (PMIC)
Number of Outputs	16
Voltage - Supply (Min)	2.3V
Voltage - Supply (Max)	5.5V
Current - Output / Channel	25mA
Dimming Control	I2C, SMBus
Operating Temperature	-40°C ~ 85°C (TA)
Package / Case	24-WQFN Exposed Pad (4x4)
Product Status	Active
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution eligibility for the LP3943ISQ/NOPB is determined by the following critical parameters: supply voltage range (2.3V–5.5V), output current per channel (25mA), package type (24-pin QFN with 4x4mm footprint), control interface (I2C/SMBus dimming), operating temperature range (-40°C to 85°C), and compliance certifications (ROHS3, REACH Unaffected, EAR99).

Two substitute parts meet these criteria:

LP3944ISQ/NOPB (Texas Instruments): Parametric equivalent with identical electrical specifications (supply voltage, output current, dimming control, temperature range, package dimensions) but reduced to 8 outputs instead of 16. Suitable for applications requiring fewer LED channels while maintaining full electrical and thermal compatibility.

PCA9552BS,118 (NXP USA Inc.): Direct manufacturer alternative with matching 16-output configuration, identical supply voltage range, output current per channel, operating temperature, and package footprint. Maintains full electrical compatibility and compliance certifications.

Parameter Comparison

Parameter	LP3943ISQ/NOPB	LP3944ISQ/NOPB	PCA9552BS,118
Manufacturer	Texas Instruments	Texas Instruments	NXP USA Inc.
Number of Outputs	16	8	16
Voltage - Supply (Min)	2.3V	2.3V	2.3V
Voltage - Supply (Max)	5.5V	5.5V	5.5V
Current - Output / Channel	25mA	25mA	25mA
Operating Temperature	-40°C ~ 85°C (TA)	-40°C ~ 85°C (TA)	-40°C ~ 85°C (TA)
Package / Case	24-WQFN Exposed Pad (4x4)	24-WQFN Exposed Pad (4x4)	24-HVQFN Exposed Pad (4x4)
Product Status	Active	Active	Active
RoHS Status	ROHS3 Compliant	ROHS3 Compliant	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)	3 (168 Hours)	1 (Unlimited)

Engineering Selection Recommendations

All three components maintain Active product status and ROHS3 compliance, ensuring long-term availability and regulatory alignment.

LP3943ISQ/NOPB to LP3944ISQ/NOPB: Select when application requirements permit reduction from 16 to 8 output channels. Both devices share identical electrical specifications and thermal characteristics. Note MSL difference: LP3943 is MSL 1 (Unlimited), while LP3944 is MSL 3 (168 Hours), affecting storage and handling protocols.

LP3943ISQ/NOPB to PCA9552BS,118: Select for cross-manufacturer substitution while maintaining 16-output configuration. Both devices are MSL 1 (Unlimited). Package designation differs (WQFN vs. HVQFN), though both are 24-pin 4x4mm footprints with exposed pads. Verify PCB layout compatibility with NXP package specifications.

Frequently Asked Questions (FAQ)

Q: Can LP3944ISQ/NOPB replace LP3943ISQ/NOPB in all applications?

A: LP3944ISQ/NOPB is electrically compatible but provides 8 outputs instead of 16. Substitution is valid only if the application requires 8 or fewer LED channels. All other electrical parameters (supply voltage, output current, dimming control, temperature range) are identical.

Q: What is the difference between WQFN and HVQFN packages?

A: Both are 24-pin QFN packages with 4x4mm footprints and exposed pads. WQFN (LP3943, LP3944) and HVQFN (PCA9552) differ in internal lead frame design. Verify PCB layout compatibility with the specific package datasheet before substitution.

Q: Does MSL rating affect component selection?

A: MSL (Moisture Sensitivity Level) determines storage and handling requirements. LP3943ISQ/NOPB and PCA9552BS,118 are MSL 1 (Unlimited storage). LP3944ISQ/NOPB is MSL 3 (168-hour limit after bag opening). Select based on manufacturing environment and storage capabilities.

Q: Are all three components I2C/SMBus compatible?

A: LP3943ISQ/NOPB and LP3944ISQ/NOPB explicitly support I2C and SMBus dimming control. PCA9552BS,118 dimming specification is not provided in available parameters. Verify NXP PCA9552 datasheet for dimming protocol compatibility before substitution.

Q: What is the inventory status for each part?

A: LP3943ISQ/NOPB: 45,565 pcs. LP3944ISQ/NOPB: 25,200 pcs. PCA9552BS,118: 3,300 pcs. All are listed as New Original In Stock.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message