PCAL6408AEXX Equivalent & Substitute Parts

Part Overview

The PCAL6408AEXX is an 8-bit I/O expander interface component manufactured by NXP USA Inc., designed for I2C and SMBus communication at 400 kHz. The device features open drain and push-pull output types with programmable interrupt output and power-on reset functionality. The PCAL6408AEXX is classified as obsolete, necessitating identification of active equivalent and substitute parts for new designs and ongoing production requirements. Substitute parts must maintain functional compatibility across I/O count, interface protocol, clock frequency, and electrical characteristics while accommodating different package configurations.

Substiute Parts

PCAL6408AEXX

NXP USA Inc.In Stock: 741PCAL6408AEXX Datasheet

Current PartRFQ

PCAL6408ABSHP

NXP USA Inc.In Stock: 8137PCAL6408ABSHP Datasheet

MFR RecommendedRFQ

MAX7321AEE+

Analog Devices Inc./Maxim IntegratedIn Stock: 3355MAX7321AEE+ Datasheet

MFR RecommendedRFQ

MAX7321AEE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 2120MAX7321AEE+T Datasheet

MFR RecommendedRFQ

MAX7321ATE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1831MAX7321ATE+T Datasheet

MFR RecommendedRFQ

SX1508BIULTRT

Semtech CorporationIn Stock: 53362SX1508BIULTRT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitute parts for the PCAL6408AEXX are selected based on the following critical parameters that determine functional compatibility:

Core Compatibility Criteria:

• Number of I/O: 8 (all substitutes maintain this requirement)
• Interface Protocol: I2C or I2C/SMBus (all substitutes support I2C minimum)
• Clock Frequency: 400 kHz (all substitutes operate at this frequency)
• Interrupt Output: Yes (all substitutes include this feature)
• Output Type: Open Drain, Push-Pull (all substitutes support both types)
• Features: POR (Power-On Reset present in all substitutes)
• Mounting Type: Surface Mount (all substitutes use surface mount technology)
• RoHS Status: ROHS3 Compliant (all substitutes meet this requirement)
• Moisture Sensitivity Level: 1 (all substitutes rated MSL 1)

Parameters Allowing Variation:

• Voltage Supply Range: Substitutes may have different minimum/maximum ratings
• Operating Temperature Range: Substitutes may have extended or different ranges
• Current Output Ratings: Substitutes may have different source/sink current specifications
• Package Configuration: Different package types accommodate various PCB layout requirements

Parameter Comparison

Engineering Selection Recommendations

PCAL6408ABSHP (NXP USA Inc.) This substitute maintains NXP manufacturer continuity and is the manufacturer-recommended replacement. It preserves identical electrical specifications including voltage supply range (1.65V ~ 5.5V), current output ratings (10mA, 25mA), and operating temperature range (-40°C ~ 85°C). The primary difference is package configuration, changing from 16-XFBGA (1.6x1.6) to 16-VFQFN Exposed Pad (3x3). Product status is active with full ROHS3 compliance and MSL 1 rating. This option is optimal for designs requiring minimal specification changes and continued NXP ecosystem support.

MAX7321AEE+ and MAX7321AEE+T (Analog Devices Inc./Maxim Integrated) These Maxim Integrated substitutes provide functional equivalence with extended operating temperature range (-40°C ~ 125°C) compared to the original part. Both maintain 8 I/O, I2C interface, 400 kHz clock frequency, and interrupt output capability. Output current is specified at 20mA, exceeding the original 10mA minimum. Voltage supply range is 1.71V ~ 5.5V, with a slightly higher minimum threshold. The primary distinction between these two parts is packaging: MAX7321AEE+ uses 16-QSOP in tube packaging, while MAX7321AEE+T uses identical 16-QSOP in tape and reel packaging. Both are active products with ROHS3 compliance and MSL 1 rating.

MAX7321ATE+T (Analog Devices Inc./Maxim Integrated) This Maxim Integrated substitute offers the same electrical specifications as MAX7321AEE+ and MAX7321AEE+T, including extended temperature range (-40°C ~ 125°C) and 20mA output current. The distinguishing feature is package configuration: 16-WFQFN Exposed Pad (3x3), providing a smaller footprint alternative to the QSOP variants. Supplied in cut tape and digi-reel packaging. Product status is active with ROHS3 compliance and MSL 1 rating.

SX1508BIULTRT (Semtech Corporation) This Semtech substitute maintains core functional compatibility with 8 I/O, I2C interface, 400 kHz clock frequency, and interrupt output. However, it operates within a reduced voltage supply range of 1.2V ~ 3.6V, making it unsuitable for applications requiring the full 5.5V upper limit of the original part. Operating temperature range matches the original at -40°C ~ 85°C. Package configuration is 20-QFN-UT (3x3), differing in pin count and footprint. Output current specifications are not provided. Product status is active with ROHS3 compliance and MSL 1 rating. Selection of this part requires verification that system voltage requirements remain within the 1.2V ~ 3.6V range.

Frequently Asked Questions (FAQ)

Q: Can PCAL6408AEXX be directly replaced with PCAL6408ABSHP without design changes? A: PCAL6408ABSHP is the manufacturer-recommended substitute and maintains identical electrical specifications. The primary change is package configuration from 16-XFBGA (1.6x1.6) to 16-VFQFN Exposed Pad (3x3). PCB layout modifications are required to accommodate the different package footprint, but no circuit design changes are necessary.

Q: What is the key difference between MAX7321AEE+ and MAX7321AEE+T? A: Both parts are electrically identical with 8 I/O, I2C interface, 400 kHz operation, and extended temperature range (-40°C ~ 125°C). The difference is packaging format: MAX7321AEE+ is supplied in tube packaging, while MAX7321AEE+T is supplied in tape and reel format. Selection depends on assembly process requirements and volume considerations.

Q: Why does SX1508BIULTRT have a different voltage supply range? A: The SX1508BIULTRT operates within 1.2V ~ 3.6V, which is a narrower range than the original PCAL6408AEXX (1.65V ~ 5.5V). This reflects the design specifications of the Semtech device. Applications requiring operation above 3.6V cannot use this substitute without external voltage regulation or redesign.

Q: Are all substitute parts ROHS3 compliant? A: Yes, all listed substitute parts are ROHS3 compliant with MSL 1 (Unlimited) moisture sensitivity level, matching the original PCAL6408AEXX specifications.

Q: What is the significance of the 16-XFBGA to 16-VFQFN package change in PCAL6408ABSHP? A: The XFBGA package is a ball grid array with 1.6x1.6mm dimensions, while VFQFN is a quad flat no-lead package with 3x3mm dimensions. The VFQFN package is larger but offers improved thermal characteristics and easier rework capability. PCB design must accommodate the different footprint, via placement, and thermal management approach.

Q: Can MAX7321 series parts be used in applications requiring SMBus protocol? A: MAX7321 series parts support I2C protocol only, not SMBus. The original PCAL6408AEXX and PCAL6408ABSHP both support I2C and SMBus. If SMBus-specific features are required, PCAL6408ABSHP is the appropriate substitute. For I2C-only applications, MAX7321 series parts are functionally equivalent.

Q: What output current specifications should be considered when selecting a substitute? A: The original PCAL6408AEXX specifies 10mA and 25mA output current. PCAL6408ABSHP maintains these ratings. MAX7321 series parts specify 20mA, which exceeds the original minimum but may not reach the 25mA maximum. SX1508BIULTRT does not specify output current. Load requirements must be evaluated against each part's specifications to ensure adequate drive capability.