Overview
The PCA9535PW is a 16-bit I²C and SMBus low-power I/O expander produced by NXP Semiconductors (previously part of Philips and now often associated with Texas Instruments in some contexts). This device is designed to provide 16 bits of General Purpose Input/Output (GPIO) expansion for I²C-bus/SMBus applications. It operates over a wide voltage range of 2.3 V to 5.5 V, making it versatile for various system designs.
Key Specifications
| Parameter | Value | Description |
|---|---|---|
| Operating Voltage | 2.3 V to 5.5 V | Voltage range for the device operation |
| Number of I/Os | 16 | Total number of General Purpose Input/Output pins |
| Interface | I²C, SMBus | Communication interfaces supported by the device |
| Clock Frequency | 400 kHz | Maximum clock frequency for I²C/SMBus operations |
| Output Type | Push-Pull | Type of output configuration for the I/O pins |
| Output Current | 10 mA, 25 mA | Maximum output current sourcing and sinking capabilities |
| Interrupt Output | Open-drain active LOW | Type of interrupt output provided by the device |
| Standby Current | 1 μA (maximum) | Ultra-low standby current consumption |
| Operating Temperature | -40°C to 85°C | Temperature range for device operation |
| Package | 24-TSSOP | Type of package the device is available in |
Key Features
- Low standby-current consumption of 1 μA maximum, reducing power consumption when the I/Os are held low
- I²C to parallel port expander, allowing for expansion of I/O capabilities over the I²C/SMBus
- Open-drain active-low interrupt output, which is activated when any input state differs from its corresponding Input Port register state
- Internal power-on reset, which sets the registers to default values and initializes the device state machine
- Schmitt-trigger action on SCL and SDA inputs, providing better noise immunity
- 5 V tolerant I/Os, allowing for flexibility in system design
- Latched outputs with a maximum drive capability of 25 mA, suitable for directly driving LEDs
- Three address pins (A0, A1, A2) for configuring the I²C bus slave address, allowing up to eight devices to share the same I²C/SMBus
Applications
- ACPI power switches
- Sensors and monitoring systems
- Push buttons and user interfaces
- LED and display control
- Fan control and other motor control applications
The PCA9535PW is particularly useful in scenarios where additional I/Os are needed without increasing the complexity of the system interconnections
Q & A
- What is the operating voltage range of the PCA9535PW?
The PCA9535PW operates over a voltage range of 2.3 V to 5.5 V
- How many I/O pins does the PCA9535PW have?
The device has 16 General Purpose Input/Output pins
- What communication interfaces does the PCA9535PW support?
The device supports I²C and SMBus interfaces
- What is the maximum clock frequency for the PCA9535PW?
The maximum clock frequency is 400 kHz
- What type of interrupt output does the PCA9535PW provide?
The device provides an open-drain active-low interrupt output
- What is the standby current consumption of the PCA9535PW?
The standby current consumption is 1 μA maximum
- What is the operating temperature range of the PCA9535PW?
The device operates from -40°C to 85°C
- How can the I²C bus slave address be configured on the PCA9535PW?
The address can be configured using three address pins (A0, A1, A2), allowing up to eight devices to share the same I²C/SMBus
- What is the purpose of the internal power-on reset in the PCA9535PW?
The internal power-on reset sets the registers to default values and initializes the device state machine
- Can the PCA9535PW directly drive LEDs?
Yes, the device has latched outputs with a maximum drive capability of 25 mA, suitable for directly driving LEDs
