PCA9557PW I/O Expander Equivalent & Substitute Parts

Part Overview

The PCA9557PW is an 8-bit I/O expander interface circuit designed for I2C and SMBus communication at 400 kHz. This Texas Instruments component operates across a 2.3V to 5.5V supply range with an operating temperature range of -40°C to 85°C. The part is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and procurement continuity. Substitute parts must maintain functional compatibility across I/O count, interface protocol, clock frequency, and package specifications.

Substiute Parts

PCA9557PW

Texas InstrumentsIn Stock: 55298PCA9557PW Datasheet

Current PartRFQ

PCA9557PWT

Texas InstrumentsIn Stock: 1648PCA9557PWT Datasheet

DirectRFQ

PCA9557PWR

Texas InstrumentsIn Stock: 30955PCA9557PWR Datasheet

MFR RecommendedRFQ

MAX7310AUE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1379MAX7310AUE+ Datasheet

MFR RecommendedRFQ

MAX7310AUE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 6146MAX7310AUE+T Datasheet

MFR RecommendedRFQ

PI4IOE5V9557LEX

Diodes IncorporatedIn Stock: 5640PI4IOE5V9557LEX Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA9557PW is determined by strict equivalence across the following critical parameters:

Primary Compatibility Criteria:

• Number of I/O: Must equal 8
• Interface Protocol: Must support I2C and/or SMBus at 400 kHz
• Package: Must be 16-TSSOP form factor
• Voltage Supply: Must support 2.3V ~ 5.5V range
• Operating Temperature: Must support -40°C minimum and 85°C minimum upper limit

Acceptable Variations:

• Current output source/sink ratings may exceed the original specification (higher current capability is acceptable)
• Operating temperature upper limit may exceed 85°C (extended temperature range is acceptable)
• Packaging format (Tube, Cut Tape, Tape & Reel) does not affect functional substitution
• Product status transition from Obsolete to Active is acceptable for design continuity

Non-Substitutable Variations:

• Reduction in I/O count below 8
• Loss of I2C or SMBus interface support
• Clock frequency below 400 kHz
• Voltage supply range that does not encompass 2.3V ~ 5.5V
• Package form factor other than 16-TSSOP

Parameter Comparison

Engineering Selection Recommendations

Texas Instruments PCA9557 Series (PCA9557PWT, PCA9557PWR): These parts maintain identical electrical specifications to the PCA9557PW. The PCA9557PWR is recommended as the primary substitute due to its Active product status and higher inventory availability (30,882 pcs). Both parts are ROHS3 compliant and carry identical compliance certifications. The transition from Tube to Cut Tape & Digi-Reel packaging does not affect functional performance.

Analog Devices Inc./Maxim Integrated MAX7310 Series (MAX7310AUE+, MAX7310AUE+T): These parts provide functional equivalence with enhanced specifications. The MAX7310AUE+ and MAX7310AUE+T both feature extended operating temperature range (-40°C to 125°C) and increased current output capability (18mA, 30mA versus 10mA, 25mA). Both are Active status components with ROHS3 compliance. The MAX7310AUE+T in Tape & Reel format offers higher inventory (6,100 pcs) compared to the Tube format MAX7310AUE+ (1,320 pcs).

Diodes Incorporated PI4IOE5V9557LEX: This part meets all primary compatibility criteria with 8 I/O, I2C interface at 400 kHz, 16-TSSOP package, and matching voltage/temperature specifications. Product status is Active with ROHS3 compliance. Output type and current specifications are not provided in available documentation. Inventory availability is 5,601 pcs in Cut Tape format.

Recommendation Priority:

1. PCA9557PWR (Active status, highest inventory, identical specifications)
2. MAX7310AUE+T (Active status, extended temperature range, high inventory)
3. MAX7310AUE+ (Active status, extended temperature range)
4. PCA9557PWT (Obsolete status, identical specifications)
5. PI4IOE5V9557LEX (Active status, limited specification data)

Frequently Asked Questions (FAQ)

Q: Can I use PCA9557PWR as a direct replacement for PCA9557PW? A: Yes. The PCA9557PWR is a direct functional equivalent with identical electrical specifications across all critical parameters: 8 I/O, I2C/SMBus 400 kHz interface, 2.3V–5.5V supply, -40°C to 85°C operating range, and 16-TSSOP package. The only difference is packaging format (Cut Tape & Digi-Reel versus Tube) and product status (Active versus Obsolete).

Q: What are the advantages of MAX7310AUE+ over PCA9557PWR? A: The MAX7310AUE+ provides two enhancements: extended operating temperature range (-40°C to 125°C versus -40°C to 85°C) and higher output current capability (18mA/30mA versus 10mA/25mA). All other parameters remain equivalent. Select MAX7310AUE+ if your application requires higher temperature operation or greater output current.

Q: Does packaging format affect substitution compatibility? A: No. Tube, Cut Tape & Digi-Reel, and Tape & Reel formats are packaging variations only and do not affect electrical or functional performance. Selection should be based on your assembly process requirements and inventory handling procedures.

Q: Is PI4IOE5V9557LEX a suitable substitute? A: Yes, PI4IOE5V9557LEX meets all primary compatibility criteria: 8 I/O, I2C 400 kHz interface, 2.3V–5.5V supply, -40°C to 85°C operating range, and 16-TSSOP package. However, output type and current specifications are not documented. Verify datasheet compatibility with your specific application requirements before selection.

Q: Why is PCA9557PW listed as Obsolete? A: Product status reflects manufacturer lifecycle classification. Obsolete status indicates the part is no longer in active production. Active alternatives (PCA9557PWR, MAX7310AUE+, MAX7310AUE+T, PI4IOE5V9557LEX) are available for new designs and ongoing procurement.

Q: Can I mix substitute parts in the same design? A: Yes, all listed substitutes are functionally equivalent and can be used interchangeably within the same circuit. However, verify that your PCB layout and assembly process accommodate the selected packaging format and any differences in pin configuration or thermal characteristics.

Q: What compliance certifications apply to all substitute parts? A: All listed parts are ROHS3 compliant, REACH unaffected, and classified under ECCN EAR99 with HTSUS code 8542.39.0001. Moisture Sensitivity Level (MSL) is 1 (Unlimited) for all parts.