PCA9538PW I/O Expander 8-Bit I2C/SMBus Interface

Part Overview

The PCA9538PW is an 8-bit I/O expander designed for I2C and SMBus communication at 400 kHz clock frequency. Manufactured by Texas Instruments, this component provides push-pull output capability with interrupt output support and power-on reset (POR) functionality. The device operates across a supply voltage range of 2.3V to 5.5V and is housed in a 16-TSSOP surface mount package.

The PCA9538PW is classified as obsolete. Identifying equivalent and substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production requirements for applications currently utilizing this component.

Substiute Parts

PCA9538PW

Texas InstrumentsIn Stock: 53196PCA9538PW Datasheet

Current PartRFQ

PCA9538APWJ

NXP USA Inc.In Stock: 3191PCA9538APWJ Datasheet

MFR RecommendedRFQ

PI4IOE5V9538LEX

Diodes IncorporatedIn Stock: 4444PI4IOE5V9538LEX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PCA9538PW are qualified based on the following critical parameters that determine functional and mechanical compatibility:

Core Electrical Parameters:

• 8-bit I/O configuration
• 400 kHz clock frequency operation
• Push-pull output type
• Interrupt output capability
• Power-on reset (POR) feature

Interface Compatibility:

• I2C and/or SMBus protocol support
• 16-TSSOP package footprint (0.173", 4.40mm Width)
• Surface mount mounting type

Supply and Operating Conditions:

• Voltage supply range compatibility (minimum 2.3V operation required)
• Operating temperature range -40°C to 85°C
• RoHS3 compliance

The identified substitute parts maintain these critical parameters while offering active product status and improved supply availability.

Parameter Comparison

Engineering Selection Recommendations

PCA9538APWJ (NXP USA Inc.) is the primary recommended substitute. This part maintains full electrical and mechanical compatibility with the PCA9538PW, including I2C and SMBus interface support, identical clock frequency, and matching package specifications. The PCA9538APWJ offers active product status with established supply availability (3100 pcs in stock). The extended lower voltage supply range (1.65V minimum) provides additional design flexibility for low-power applications. RoHS3 compliance and identical operating temperature range ensure regulatory and thermal compatibility.

PI4IOE5V9538LEX (Diodes Incorporated) serves as a secondary substitute option. This part provides the same 8-bit I/O configuration, 400 kHz operation, and 16-TSSOP package footprint. The PI4IOE5V9538LEX supports SMBus protocol and maintains the same voltage supply range as the original part (2.3V ~ 5.5V). Active product status and strong inventory availability (4348 pcs in stock) support production continuity. Note that this part specifies SMBus interface without explicit I2C confirmation, and operating temperature range is not provided in available documentation.

Both substitute parts carry ROHS3 compliance and MSL Level 1 rating, matching the original component's environmental and handling specifications.

Frequently Asked Questions (FAQ)

Q: Can PCA9538APWJ be used as a direct replacement for PCA9538PW?

A: Yes. The PCA9538APWJ maintains identical I/O count (8-bit), clock frequency (400 kHz), output type (push-pull), package footprint (16-TSSOP), and operating temperature range (-40°C to 85°C). Both parts support I2C and SMBus protocols. The PCA9538APWJ offers extended lower voltage operation (1.65V minimum vs. 2.3V minimum), which is compatible with designs using the original 2.3V minimum specification.

Q: What is the key difference between PCA9538APWJ and PI4IOE5V9538LEX?

A: Both parts provide 8-bit I/O expansion at 400 kHz in 16-TSSOP packages. The primary difference is interface specification: PCA9538APWJ explicitly supports both I2C and SMBus, while PI4IOE5V9538LEX specifies SMBus support. For applications requiring I2C protocol, PCA9538APWJ is the more appropriate choice. Additionally, PCA9538APWJ provides documented operating temperature range (-40°C to 85°C), while PI4IOE5V9538LEX does not specify this parameter.

Q: Are the 16-TSSOP packages physically identical?

A: Yes. All three parts use 16-TSSOP packages with identical dimensions (0.173" width, 4.40mm width specification). PCB footprints and land patterns are compatible across all three parts, enabling direct board-level substitution without layout modifications.

Q: Do all substitute parts meet RoHS compliance requirements?

A: Yes. Both PCA9538APWJ and PI4IOE5V9538LEX are ROHS3 compliant, matching the original PCA9538PW specification. All parts carry MSL Level 1 (Unlimited) moisture sensitivity rating.

Q: Why is the PCA9538PW classified as obsolete?

A: The PCA9538PW is no longer in active production. The substitute parts (PCA9538APWJ and PI4IOE5V9538LEX) are actively manufactured and supported, providing long-term supply chain stability for new designs and ongoing production requirements.