PCA9557DBR Equivalent & Substitute Parts

Part Overview

The PCA9557DBR is an 8-bit I/O expander IC designed for I2C and SMBus communication at 400 kHz, packaged in a 16-SSOP surface mount configuration. This device provides open drain and push-pull output options with a supply voltage range of 2.3V to 5.5V and operates across -40°C to 85°C. The PCA9557DBR is classified as obsolete, making identification of compatible substitute parts essential for ongoing system support and new design implementations.

Substiute Parts

PCA9557DBR

Texas InstrumentsIn Stock: 2129PCA9557DBR Datasheet

Current PartRFQ

PCA9557PWR

Texas InstrumentsIn Stock: 30955PCA9557PWR Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PCA9557DBR is determined by strict equivalence across the following critical parameters:

• Base product number (PCA9557 series)
• I/O count (8 channels)
• Interface protocol (I2C, SMBus 400 kHz)
• Output configuration (Open Drain, Push-Pull)
• Current specifications (10mA, 25mA source/sink)
• Supply voltage range (2.3V ~ 5.5V)
• Operating temperature range (-40°C ~ 85°C)
• RoHS and compliance certifications

The PCA9557PWR qualifies as a direct substitute based on identical electrical and functional specifications. The primary difference is the package type: PCA9557DBR uses 16-SSOP (0.209", 5.30mm width), while PCA9557PWR uses 16-TSSOP (0.173", 4.40mm width). Both packages are surface mount configurations with equivalent pin functionality and electrical performance.

Parameter Comparison

Engineering Selection Recommendations

The PCA9557PWR is the recommended substitute for the obsolete PCA9557DBR. Both devices maintain identical electrical specifications, functional capabilities, and compliance certifications (ROHS3, REACH Unaffected, EAR99). The PCA9557PWR is currently in active production status with significantly higher inventory availability (30,882 pcs vs. 2,100 pcs), ensuring long-term supply chain reliability.

The primary design consideration is package footprint compatibility. The PCA9557PWR uses a narrower 16-TSSOP package (4.40mm width) compared to the 16-SSOP package (5.30mm width) of the PCA9557DBR. PCB layout modifications may be required to accommodate the reduced package width, but pin functionality and electrical performance remain fully equivalent.

Frequently Asked Questions (FAQ)

Q: Are the PCA9557DBR and PCA9557PWR electrically identical?

A: Yes. Both devices share identical electrical specifications including I/O count, interface protocol, clock frequency, output types, current ratings, supply voltage range, and operating temperature range.

Q: What is the primary difference between these two parts?

A: The package type differs. PCA9557DBR uses 16-SSOP (0.209", 5.30mm width), while PCA9557PWR uses 16-TSSOP (0.173", 4.40mm width). Both are surface mount packages with equivalent pin configurations.

Q: Can I use PCA9557PWR as a direct replacement on existing PCA9557DBR PCBs?

A: Pin functionality is equivalent, but PCB footprint compatibility must be verified. The narrower TSSOP package may require layout modifications. Consult PCB design files and package datasheets to confirm footprint compatibility before implementation.

Q: Why is the PCA9557DBR listed as obsolete?

A: The PCA9557DBR has reached end-of-life status. The PCA9557PWR remains in active production and is the recommended alternative for new designs and ongoing system support.

Q: Are compliance certifications maintained with the substitute part?

A: Yes. The PCA9557PWR maintains ROHS3 compliance, REACH unaffected status, and EAR99 classification identical to the PCA9557DBR.

Q: What inventory considerations should I account for?

A: The PCA9557PWR has substantially higher inventory availability (30,882 pcs) compared to the PCA9557DBR (2,100 pcs), providing improved supply chain security for production requirements.