PCA9545AD,112 Equivalent & Substitute Parts

Part Overview

The PCA9545AD,112 is a 4-Channel I2C Switcher Interface manufactured by NXP USA Inc., housed in a 20-SO package. This specialized interface component enables multiplexing of I2C bus lines across four independent channels, supporting voltage supplies from 2.3V to 3.6V and 4.5V to 5.5V. The product is currently classified as Obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations.

Substiute Parts

PCA9545AD,112

NXP USA Inc.In Stock: 1953PCA9545AD,112 Datasheet

Current PartRFQ

BU6521KV-E2

Rohm SemiconductorIn Stock: 2440BU6521KV-E2 Datasheet

MFR RecommendedRFQ

PCA9545ADW

Texas InstrumentsIn Stock: 893PCA9545ADW Datasheet

MFR RecommendedRFQ

PCA9545ADWR

Texas InstrumentsIn Stock: 3202PCA9545ADWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the PCA9545AD,112 is determined by the following critical parameters:

Primary Substitution Criteria:

• Interface functionality: I2C or SMBus compatibility
• Package compatibility: 20-SOIC form factor (0.295", 7.50mm Width)
• Voltage supply range: Support for 2.3V ~ 5.5V operating range
• Mounting type: Surface Mount
• Compliance: ROHS3 Compliant, REACH Unaffected

Substitute Parts Identified:

1. PCA9545ADW (Texas Instruments) – Direct functional equivalent with identical package and interface specifications. Supports extended voltage range (2.3V ~ 5.5V). Product Status: Last Time Buy.

2. PCA9545ADWR (Texas Instruments) – Functionally identical to PCA9545ADW with alternative packaging (Cut Tape & Digi-Reel®). Supports extended voltage range (2.3V ~ 5.5V). Product Status: Last Time Buy.

3. BU6521KV-E2 (Rohm Semiconductor) – Listed as manufacturer-recommended substitute. Note: This is a Video Encoder IC with different primary application (Camera), different package (48-VQFPC), and different voltage specifications (2.7V ~ 3.6V analog, 1.5V/3.3V digital). This substitute is functionally distinct and not recommended for direct replacement in I2C switching applications.

Parameter Comparison

Engineering Selection Recommendations

Recommended Substitutes for I2C Switching Applications:

Primary Choice: PCA9545ADW or PCA9545ADWR

Both Texas Instruments variants maintain functional equivalence with the obsolete PCA9545AD,112. They provide identical package geometry (20-SOIC), support the required voltage range (2.3V ~ 5.5V), and maintain I2C/SMBus interface compatibility. Both are ROHS3 Compliant with MSL 1 rating. Selection between these two depends on packaging requirements: PCA9545ADW is supplied in Tube packaging, while PCA9545ADWR is supplied in Cut Tape & Digi-Reel® format.

Not Recommended: BU6521KV-E2

While listed as a manufacturer-recommended substitute, the BU6521KV-E2 is a Video Encoder IC designed for camera applications. It operates in a different functional domain (video encoding vs. I2C switching), uses an incompatible package (48-VQFPC vs. 20-SOIC), and has different voltage specifications. This part is not suitable for direct replacement in I2C multiplexing circuits.

Frequently Asked Questions (FAQ)

Q: Can PCA9545ADW directly replace PCA9545AD,112 on existing PCBs?

A: Yes. Both parts use identical 20-SOIC package geometry (0.295", 7.50mm Width) and pin configuration. PCB layout and footprints are compatible without modification.

Q: What is the difference between PCA9545ADW and PCA9545ADWR?

A: Both parts are functionally identical with the same electrical specifications and package. The difference is in packaging format: PCA9545ADW is supplied in Tube packaging, while PCA9545ADWR is supplied in Cut Tape & Digi-Reel® format. Selection depends on assembly line requirements and inventory management preferences.

Q: Why is BU6521KV-E2 listed as a substitute if it is not compatible?

A: BU6521KV-E2 is listed in the manufacturer's substitute field but serves a different application domain (video encoding for camera systems). It is not a functional equivalent for I2C switching applications and should not be used as a replacement for the PCA9545AD,112.

Q: Are the Texas Instruments substitutes still available?

A: Both PCA9545ADW and PCA9545ADWR are classified as Last Time Buy, indicating limited remaining inventory. Procurement should prioritize these parts for new designs or system updates before availability is exhausted.

Q: Do the substitute parts maintain the same compliance certifications?

A: Yes. Both PCA9545ADW and PCA9545ADWR are ROHS3 Compliant, REACH Unaffected, with MSL 1 (Unlimited) rating, matching the compliance profile of the original PCA9545AD,112.

Q: What voltage range should be used for the substitute parts?

A: The Texas Instruments substitutes support a continuous voltage range of 2.3V ~ 5.5V, which encompasses the original part's dual-range specification (2.3V ~ 3.6V and 4.5V ~ 5.5V). Designs operating within the original voltage windows will function without modification.