Overview
The PCA9535DW, produced by Texas Instruments, is a 16-bit I2C and SMBus low-power I/O expander. This device is designed to provide 16 bits of general-purpose parallel input/output (GPIO) expansion for I2C-bus and SMBus applications. It is particularly useful in scenarios where additional I/O ports are needed, such as in ACPI power switches, sensors, push buttons, LEDs, and fans.
Key Specifications
| Parameter | Value | Notes |
|---|---|---|
| Operating Voltage Range | 2.3 V to 5.5 V | |
| I/O Voltage Tolerance | Up to 5.5 V | |
| Number of I/O Pins | 16 | Configurable as inputs or outputs |
| Default I/O Configuration at Power-On | Inputs | |
| Clock Frequency Range | 0 Hz to 400 kHz | |
| Standby Current | Max 1 μA | VI = GND, IO = 0, I/O = inputs, fSCL = 0 kHz |
| Interrupt Output | Open-drain active-low | Activated when input state differs from corresponding Input Port register state |
| Package Type | 24-SOIC | |
| Operating Temperature Range | -40°C to 85°C | |
| ESD Protection | Exceeds 2000 V HBM, 200 V MM, 1000 V CDM | Per JESD22-A114, JESD22-A115, and JESD22-C101 |
Key Features
- Low standby-current consumption of 1 μA max.
- I2C to parallel port expander with interrupt and configuration registers.
- Open-drain active-low interrupt output.
- Polarity Inversion register for active-high or active-low operation.
- No glitch on power-up.
- Internal power-on reset.
- Individual I/O configuration.
- 5 V I/O tolerance.
- Noise filter on SCL/SDA inputs.
- Up to eight devices can share the same I2C bus or SMBus using hardware pins A0, A1, and A2 to vary the fixed I2C address.
Applications
The PCA9535DW is suitable for various applications requiring additional I/O ports, including:
- ACPI power switches.
- Sensors and monitoring systems.
- Push buttons and other user interfaces.
- LED indicators and display systems.
- Fans and other motor control systems.
Q & A
- What is the operating voltage range of the PCA9535DW?
The PCA9535DW operates within a voltage range of 2.3 V to 5.5 V.
- How many I/O pins does the PCA9535DW have?
The PCA9535DW has 16 I/O pins, which can be configured as either inputs or outputs.
- What is the default configuration of the I/O pins at power-on?
The I/O pins are configured as inputs by default at power-on.
- What is the maximum standby current of the PCA9535DW?
The maximum standby current is 1 μA.
- How does the interrupt output function?
The interrupt output is an open-drain active-low output that is activated when any input state differs from its corresponding Input Port register state.
- What is the clock frequency range supported by the PCA9535DW?
The clock frequency range is from 0 Hz to 400 kHz.
- Can multiple PCA9535DW devices share the same I2C bus?
Yes, up to eight devices can share the same I2C bus or SMBus using hardware pins A0, A1, and A2 to vary the fixed I2C address.
- What type of ESD protection does the PCA9535DW have?
The PCA9535DW exceeds 2000 V HBM, 200 V MM, and 1000 V CDM per JESD22-A114, JESD22-A115, and JESD22-C101.
- What is the operating temperature range of the PCA9535DW?
The operating temperature range is -40°C to 85°C.
- Does the PCA9535DW have any noise filtering capabilities?
Yes, it has noise filters on the SCL/SDA inputs.
