PCA9534ADW Equivalent & Substitute Parts

Part Overview

The PCA9534ADW is an 8-bit I/O expander interface component manufactured by Texas Instruments, designed for I2C and SMBus communication at 400 kHz. This device is classified as Last Time Buy, indicating discontinued production with limited inventory availability. The component operates across a supply voltage range of 2.3V to 5.5V and supports operating temperatures from -40°C to 85°C. Finding equivalent and substitute parts is necessary due to the Last Time Buy status, which restricts future procurement from the original manufacturer.

Substiute Parts

PCA9534ADW

Texas InstrumentsIn Stock: 877PCA9534ADW Datasheet

Current PartRFQ

TCA9534ADWR

Texas InstrumentsIn Stock: 3016TCA9534ADWR Datasheet

MFR RecommendedRFQ

MAX7328AWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 724MAX7328AWE+ Datasheet

MFR RecommendedRFQ

MAX7329AWE+

Analog Devices Inc./Maxim IntegratedIn Stock: 1206MAX7329AWE+ Datasheet

MFR RecommendedRFQ

MAX7329AWE+T

Analog Devices Inc./Maxim IntegratedIn Stock: 1106MAX7329AWE+T Datasheet

MFR RecommendedRFQ

PCA9534D,118

NXP USA Inc.In Stock: 4206PCA9534D,118 Datasheet

MFR RecommendedRFQ

PCF8574AT/3,518

NXP SemiconductorsIn Stock: 17634PCF8574AT/3,518 Datasheet

MFR RecommendedRFQ

PCF8574T/3,512

NXP USA Inc.In Stock: 2237PCF8574T/3,512 Datasheet

MFR RecommendedRFQ

PCF8574T/3,518

NXP USA Inc.In Stock: 2285PCF8574T/3,518 Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the PCA9534ADW is determined by the following critical parameters: 8 I/O count, I2C interface support, 16-SOIC package form factor, interrupt output capability, and push-pull output type. The clock frequency, voltage supply range, and output current specifications define functional compatibility boundaries.

Substitute parts are grouped into two categories:

Direct Equivalents (Full Parameter Compatibility): Parts that maintain 400 kHz clock frequency, I2C/SMBus interface, push-pull output, and identical voltage supply specifications. These include TCA9534ADWR and PCA9534D,118.

Functional Alternatives (Reduced Clock Frequency): Parts that support I2C interface with 8 I/O and interrupt output but operate at 100 kHz clock frequency. These include MAX7329AWE+, MAX7329AWE+T, PCF8574T/3,512, PCF8574AT/3,518, and PCF8574T/3,518. These alternatives are suitable for applications where 100 kHz I2C communication meets system requirements.

Limited Compatibility (Different Output Type): MAX7328AWE+ provides 8 I/O and 2-Wire interface but uses open-drain output and lacks interrupt output capability, limiting its substitution scope.

Parameter Comparison

Engineering Selection Recommendations

For Direct Replacement (400 kHz I2C/SMBus Required):

TCA9534ADWR is the primary direct equivalent, offering identical 400 kHz clock frequency and I2C/SMBus interface with push-pull output. This part is in Active product status with expanded voltage supply range (1.65V ~ 5.5V), providing superior low-voltage operation capability. Inventory availability is 2,951 units.

PCA9534D,118 provides equivalent electrical specifications with 400 kHz operation and identical voltage supply range. This NXP alternative maintains full I2C/SMBus compatibility and push-pull output characteristics. Inventory availability is 4,151 units.

For 100 kHz I2C Applications:

PCF8574T/3,512 and PCF8574T/3,518 are suitable when 100 kHz I2C communication satisfies system requirements. Both maintain push-pull output, interrupt capability, and identical package form factor. These parts support extended voltage range (2.5V ~ 6V) and offer high inventory availability (2,220 and 2,200 units respectively).

MAX7329AWE+ and MAX7329AWE+T provide 100 kHz I2C operation with extended operating temperature range (-40°C ~ 125°C). Both use open-drain output, which requires pull-up resistor configuration. Inventory availability is 1,162 and 1,021 units respectively.

Not Recommended for Direct Substitution:

MAX7328AWE+ lacks interrupt output capability and uses 2-Wire interface with open-drain output, making it unsuitable for applications requiring interrupt-driven operation.

Frequently Asked Questions (FAQ)

Q: Can TCA9534ADWR directly replace PCA9534ADW?

A: Yes. TCA9534ADWR maintains identical 400 kHz I2C/SMBus interface, 8 I/O count, push-pull output, and 16-SOIC package. The lower minimum voltage specification (1.65V vs 2.3V) provides additional design flexibility. Both are ROHS3 compliant with unlimited moisture sensitivity rating.

Q: What is the impact of using a 100 kHz substitute instead of 400 kHz?

A: Clock frequency reduction from 400 kHz to 100 kHz decreases I2C communication speed by 75%. This is acceptable for applications with non-time-critical I/O expansion requirements. System firmware must accommodate the reduced bus speed; no hardware modifications are required.

Q: Are open-drain output parts (MAX7329AWE+) compatible with push-pull designs?

A: Open-drain output requires external pull-up resistors to the supply voltage, whereas push-pull output does not. Designs using push-pull output cannot be directly substituted with open-drain parts without circuit modification. Verify pull-up resistor presence in the target application before substitution.

Q: Does voltage supply range affect substitution eligibility?

A: Voltage supply range differences do not prevent substitution if the application supply voltage falls within both part specifications. For example, a 3.3V system can use either PCA9534ADW (2.3V ~ 5.5V) or TCA9534ADWR (1.65V ~ 5.5V). Verify application supply voltage against substitute part specifications before selection.

Q: What is the significance of Last Time Buy status?

A: Last Time Buy indicates the manufacturer has discontinued production and will not accept new orders after a specified date. Existing inventory is limited. Substitution with Active status parts (TCA9534ADWR, PCA9534D,118, PCF8574 series) ensures long-term availability for future production runs and design revisions.

Q: Are all substitute parts ROHS3 compliant?

A: Yes. All listed substitute parts maintain ROHS3 compliance, matching the original PCA9534ADW specification. All parts are REACH Unaffected and classified as EAR99 for export control purposes.

Q: Can PCF8574 series parts replace PCA9534ADW in SMBus applications?

A: No. PCF8574 series parts support I2C interface only and do not support SMBus protocol. Use PCA9534D,118 or TCA9534ADWR for applications requiring SMBus compatibility.