PCA8575DB,118 Equivalent & Substitute Parts

Part Overview

The PCA8575DB,118 is a 16-bit I/O expander with I2C interface operating at 400 kHz, manufactured by NXP USA Inc. in a 24-SSOP surface mount package. This component is classified as Active and fully compliant with RoHS3 and REACH standards. Substitute parts are necessary when the primary part experiences supply constraints, obsolescence of related variants, or when design requirements permit alternative manufacturers offering equivalent or enhanced electrical characteristics within the same package footprint.

Substiute Parts

PCA8575DB,118

NXP USA Inc.In Stock: 2503PCA8575DB,118 Datasheet

Current PartRFQ

PCF8575DBR

Texas InstrumentsIn Stock: 16933PCF8575DBR Datasheet

DirectRFQ

MAX7312AAG+

Analog Devices Inc./Maxim IntegratedIn Stock: 3806MAX7312AAG+ Datasheet

MFR RecommendedRFQ

MAX7318AAG+

Analog Devices Inc./Maxim IntegratedIn Stock: 1184MAX7318AAG+ Datasheet

MFR RecommendedRFQ

PCF8575DB

Texas InstrumentsIn Stock: 1432PCF8575DB Datasheet

MFR RecommendedRFQ

SX1509QBIULTRT

Semtech CorporationIn Stock: 2173SX1509QBIULTRT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA8575DB,118 is determined by the following critical parameters:

Primary Substitution Criteria:

• 16 I/O channels (mandatory)
• I2C interface at 400 kHz clock frequency (mandatory)
• 24-SSOP package footprint (mandatory for direct PCB compatibility)
• Push-Pull output type (mandatory for equivalent electrical behavior)
• Interrupt output capability (mandatory)
• Power-On Reset (POR) feature (mandatory)
• Surface mount technology (mandatory)

Secondary Compatibility Parameters:

• Supply voltage range (minimum 2.3V required; extended ranges acceptable)
• Operating temperature range (-40°C minimum required; extended ranges acceptable)
• Output current specifications (25mA sink capability required; source current variations acceptable within design margins)
• RoHS3 and REACH compliance (mandatory for regulatory equivalence)

Substitute parts meeting all primary criteria are classified as direct functional equivalents. Parts with identical package and interface specifications but differing secondary parameters (voltage range, temperature range, output current) remain compatible provided the application requirements fall within the substitute part's operating envelope.

Parameter Comparison

Engineering Selection Recommendations

Direct Package-Compatible Substitutes (24-SSOP):

PCF8575DBR (Texas Instruments) and PCF8575DB (Texas Instruments) are functionally equivalent I/O expanders with identical package geometry, I2C interface, and 400 kHz clock frequency. PCF8575DBR is Active status with 16,840 units in stock, while PCF8575DB is Obsolete status with 1,407 units in stock. Both support SMBus in addition to I2C. PCF8575DBR is the preferred Texas Instruments alternative due to active product status and superior inventory availability.

MAX7312AAG+ and MAX7318AAG+ (Analog Devices Inc./Maxim Integrated) are Active status I/O expanders with identical 16-channel, 400 kHz I2C/SMBus interface in 24-SSOP package. Both offer extended operating temperature range (-40°C ~ 125°C) and higher output current capability (31mA source, 43mA sink) compared to the primary part. MAX7312AAG+ has 3,712 units in stock; MAX7318AAG+ has 1,155 units in stock. These parts are suitable for applications requiring enhanced thermal performance or higher drive current.

Alternative Package Substitute (28-QFN):

SX1509QBIULTRT (Semtech Corporation) is an Active status I/O expander with 16 channels and 400 kHz I2C interface. This part differs in package format (28-UFQFN Exposed Pad versus 24-SSOP) and therefore requires PCB redesign. The SX1509QBIULTRT offers additional integrated features including keypad controller and LED output functionality. Supply voltage range is restricted to 1.425V ~ 3.6V, limiting applicability to low-voltage designs. This substitute is suitable only when PCB layout modification is feasible and low-voltage operation is required.

Product Status Consideration:

PCF8575DB carries Obsolete status and should not be selected for new designs despite functional equivalence. Active status parts (PCF8575DBR, MAX7312AAG+, MAX7318AAG+, SX1509QBIULTRT) are recommended for long-term supply security and design continuity.

Frequently Asked Questions (FAQ)

Q: Can PCF8575DBR directly replace PCA8575DB,118 without PCB modification?

A: Yes. PCF8575DBR is a direct substitute with identical 24-SSOP package footprint, 16-channel I/O configuration, 400 kHz I2C interface, and Push-Pull output type. Pin-to-pin compatibility is maintained. SMBus support in PCF8575DBR is a superset of I2C functionality and does not affect I2C-only applications.

Q: What is the key difference between MAX7312AAG+ and MAX7318AAG+?

A: Both parts are functionally equivalent with identical electrical specifications. The primary difference is base product number designation (MAX7312 versus MAX7318). Both offer 16 I/O channels, 400 kHz I2C/SMBus interface, extended temperature range (-40°C ~ 125°C), and higher output current (31mA source, 43mA sink). Selection between these parts is determined by inventory availability and supplier preference.

Q: Why does SX1509QBIULTRT require PCB redesign?

A: SX1509QBIULTRT uses a 28-UFQFN Exposed Pad package, which differs from the 24-SSOP package of the primary part. Pin count and physical footprint are incompatible with existing PCB layouts designed for 24-SSOP devices. PCB redesign is mandatory for this substitute.

Q: Is PCF8575DB suitable for new designs?

A: No. PCF8575DB carries Obsolete product status. Although functionally equivalent to the primary part, obsolete components present supply chain risk and should not be selected for new designs. Active status alternatives (PCF8575DBR, MAX7312AAG+, MAX7318AAG+) are recommended.

Q: What supply voltage range applies when selecting a substitute?

A: The primary part operates at 2.3V ~ 5.5V. All recommended substitutes support this range or an extended range. PCF8575DBR and PCF8575DB support 2.5V ~ 5.5V (compatible with applications above 2.5V). MAX7312AAG+ and MAX7318AAG+ support 2V ~ 5.5V (compatible with all primary part applications). SX1509QBIULTRT supports 1.425V ~ 3.6V (restricted to low-voltage applications only). Verify application supply voltage requirements before selection.

Q: Are all substitutes RoHS3 compliant?

A: Yes. All recommended substitutes carry RoHS3 Compliant or RoHS Compliant status. PCF8575DBR, MAX7312AAG+, MAX7318AAG+, and PCF8575DB are RoHS3 Compliant. SX1509QBIULTRT is RoHS Compliant. All parts meet REACH Unaffected status.

Q: Can output current differences affect circuit design?

A: Yes. The primary part provides 100µA source and 25mA sink current. Substitutes vary: PCF8575DBR (1mA source, 25mA sink), MAX7312AAG+ and MAX7318AAG+ (31mA source, 43mA sink), SX1509QBIULTRT (8mA source, 15mA sink). Applications requiring specific source current levels must verify substitute specifications. Higher current capability (MAX7312AAG+, MAX7318AAG+) permits direct LED driving without external buffers; lower current capability (SX1509QBIULTRT) may require external drivers for high-current loads.