PCA9534DW - 8-Bit I2C GPIO Expander | Texas Instruments
MPN: PCA9534DW ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.51 | $2.51 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
PCA9534DW Overview
An I2C I/O expander is a peripheral that adds digital input and output pins to a host controller through a two-wire serial interface. The PCA9534 belongs to the GPIO expander and port-extension hierarchy, where a microcontroller or processor uses serial addressing to control external LEDs, relays, sensors, or digital status signals while reducing direct GPIO requirements.
Key features include eight configurable GPIO lines, a 2.3 V to 5.5 V VCC range, 400 kHz I2C/SMBus operation, push-pull outputs, an interrupt output, and configuration registers. The device is identified in distributor data as a 16-SOIC I/O expander. Its low-power design is useful for embedded systems that need additional control or monitoring lines without dedicating eight host-controller pins to every function.
The PCA9534 uses configuration registers to determine whether each port pin operates as input, output, or high impedance. The interrupt output provides a hardware indication of input or register conditions, while the I2C interface allows the host to read and update port state. The 400 kHz bus rate supports relatively compact embedded control systems, although actual system throughput depends on bus capacitance, pull-up implementation, and host timing.
Typical applications include low-power sensor nodes, industrial control boards, LED or indicator expansion, relay-control interfaces, and general embedded GPIO expansion. In designs using the PCA9534DW, the host processor must provide valid I2C pull-ups, respect the 2.3 V to 5.5 V supply range, and account for the interrupt pin when configuring input-change detection. The 16-SOIC package also requires a PCB footprint matching the SOIC-16 layout.
For sourcing, distributor listings provide current market, price, and inventory information, while the manufacturer datasheet remains the controlling reference for pinout, register behavior, electrical limits, and application use. Product availability should be checked directly with an authorized distributor because inventory and pricing change over time.
Drop-in alternatives for PCA9534DW — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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Request AlternativesPCA9534DW Specifications
| Device Type | 8-bit I2C/SMBus I/O expander |
| Number of I/O Ports | 8 |
| Supply Voltage Range | 2.3 V to 5.5 V |
| I2C/SMBus Maximum Frequency | 400 kHz |
| Interface | I2C/SMBus |
| Output Type | Push-pull |
| Interrupt Output | Yes |
| Configuration Registers | Yes |
| Power-On Reset | Yes |
| Operating Temperature | -40 C to +85 C |
| Package | 16-SOIC |
| Technology | CMOS |
| Number of Pins | 16 |
| Mounting Type | Surface Mount |
| Low-Power Operation | Low-power I/O expander |
| I/O Configuration | Input, output, or high-impedance modes |
PCA9534DW 16-soic Pin Configuration Guide
Pin configuration for PCA9534DW (16-soic package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for PCA9534DW.
Refer to the datasheet for full pin configuration.
Typical Applications
PCA9534DW is suitable for 6 applications: Industrial Sensor and Control Node, Low-Power IoT Sensor Interface, LED and Indicator Expansion, Relay and Discrete Control Interface, Embedded System Status Monitoring, Communication and Network Equipment Control.
Industrial Sensor and Control Node
The PCA9534DW fits industrial sensor nodes that need more digital control or status signals than the host controller provides directly. Its eight push-pull outputs can drive enables, reset lines, status indicators, or logic-level control inputs while the host communicates through I2C/SMBus at up to 400 kHz. The 2.3 V to 5.5 V supply range supports low-voltage embedded systems, while the interrupt output can notify the host of selected input events. Because the expander is not a high-current driver, relays and larger loads still require appropriate external transistors or driver circuits.
Recommended
Low-Power IoT Sensor Interface
The PCA9534DW is useful in low-power IoT sensor interfaces because it provides eight remotely controlled I/O lines while operating from 2.3 V to 5.5 V. A host can use the outputs for sensor enables, reset inputs, or local indicator controls without dedicating multiple package pins to those functions. The I2C/SMBus interface and 400 kHz maximum bus rate support embedded control architectures. Designers should account for pull-up current, bus capacitance, interrupt behavior, and the power consumed by external loads when calculating battery life.
Recommended
LED and Indicator Expansion
The PCA9534DW can centralize LED and indicator control in a compact embedded product by driving eight push-pull logic outputs. The host can set each line as an output and update the output register over I2C, reducing direct GPIO usage on a microcontroller or processor. For visible LEDs, use the appropriate current-limiting resistor and verify the LED current against the device's electrical limits. For high-current lamps or illumination modules, add a suitable driver stage rather than loading the expander beyond its specified output capability.
Recommended
Relay and Discrete Control Interface
The PCA9534DW can provide the logic-control layer for relays, latches, and discrete system actuators, but it should not be treated as a power driver. Its eight outputs can control transistor or gate-driver inputs, while the host updates the state through I2C/SMBus. This arrangement is useful in automation and embedded equipment where a controller needs more outputs than its native GPIO package provides. Confirm the output voltage, current, polarity, isolation requirements, and external transistor sizing against the final load and the manufacturer datasheet.
Recommended
Embedded System Status Monitoring
The PCA9534DW can monitor multiple digital status signals and bring them back to a host processor over I2C/SMBus. Eight configurable lines support input, output, or high-impedance operation, allowing one device to handle both sensed status and local control functions. The interrupt output can reduce unnecessary polling when the application needs event notification. Designers should define input levels, debounce requirements, pull-ups or pull-downs, and reset behavior in the system firmware and schematic.
Recommended
Communication and Network Equipment Control
The PCA9534DW can support auxiliary control functions in communication equipment where a baseband or processor requires discrete GPIO lines for module enables, alarms, indicators, or reset sequencing. The I2C/SMBus interface keeps the control connection compact, while the 2.3 V to 5.5 V range allows use in low-voltage digital systems. The interrupt output can help the host react to external events, but the system designer must verify address assignment, pull-up placement, bus loading, and any isolation requirements specific to the equipment.
Recommended
Recommended Products Summary
Engineering reference data for PCA9534DW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Brand | Texas Instruments |
| Package | 16-SOIC |
| I/O Count | 8 |
| Supply Voltage | 2.3 V to 5.5 V |
| I2C/SMBus Frequency | 400 kHz |
| Interface | I2C/SMBus |
| Interrupt Output | Yes |
| Power-On Reset | Yes |
| Operating Temperature | -40 C to +85 C |
| Output Type | Push-pull |
Key Differentiators
- Eight configurable I/O lines with push-pull outputs (vs PCA9554ADW)
- 400 kHz I2C/SMBus operation (vs PCA9538DW)
- Interrupt and configuration-register support (vs PCA9554ADW)
Design Notes
Place the PCA9534DW close to the connector, indicator, or control circuits that use its eight I/O lines. Keep I2C SDA and SCL traces short, route them away from noisy switching nodes, and place the required pull-up resistors near the bus master or according to the system bus topology. Confirm that the selected SOIC-16 footprint matches the PCB land pattern and orientation before fabrication.
Decouple VCC with the capacitance specified by the manufacturer guidance and maintain the verified 2.3 V to 5.5 V operating range. Because I2C pull-ups can continuously draw current, include that static load in the power budget. If an external LED or actuator is attached, calculate its current and ensure the output stage remains within the device limits; use a transistor or dedicated driver when the load exceeds the expander's capability.
Do not assume that a shared 16-SOIC package makes a substitute pin-compatible. Verify supply limits, I2C address selection, register compatibility, interrupt polarity, output drive, and every pin function against the candidate datasheet. The verified comparison results mention PCA9554ADW and PCA9538DW, but the supplied excerpts do not establish drop-in equivalence; obtain manufacturer documentation and validate firmware before substitution.
Compliance Information
The verified excerpts identify the product, package, electrical interface, and distributor data but do not provide compliance declarations. Compliance status must be confirmed from the current manufacturer product documentation or supplier certificates.