The "TCA9535PWR" is a part number for a device produced by Texas Instruments (TI). It is an I/O expander, and specifically, the TCA9535 is an 8-bit I/O expander with an I2C interface . This device is used to expand the I/O capabilities of microcontrollers and other digital systems.
Package and Pin Configuration:
Package Type: TCA9535PWR typically comes in a TSSOP-20 (Thin Shrink Small Outline Package). This means the device has 20 pins in total.Pin Function Specifications and Description of Each Pin:
Below is a detailed list of the 20 pins for the TCA9535PWR in the TSSOP-20 package.
Pin Number Pin Name Pin Type Pin Function Description 1 VSS Power Ground (0V) power supply pin. 2 SDA Input/Output Serial Data Line for I2C communication. Connects to the data line of the I2C bus. 3 SCL Input/Output Serial Clock Line for I2C communication. Connects to the clock line of the I2C bus. 4 A0 Input I2C Address Pin 0. Determines the least significant bit (LSB) of the I2C address. 5 A1 Input I2C Address Pin 1. Determines the second bit of the I2C address. 6 A2 Input I2C Address Pin 2. Determines the third bit of the I2C address. 7 RESET Input Active low reset input. Used to reset the device. 8 P0.0 I/O General purpose I/O pin 0. Configurable as input or output. 9 P0.1 I/O General purpose I/O pin 1. Configurable as input or output. 10 P0.2 I/O General purpose I/O pin 2. Configurable as input or output. 11 P0.3 I/O General purpose I/O pin 3. Configurable as input or output. 12 P0.4 I/O General purpose I/O pin 4. Configurable as input or output. 13 P0.5 I/O General purpose I/O pin 5. Configurable as input or output. 14 P0.6 I/O General purpose I/O pin 6. Configurable as input or output. 15 P0.7 I/O General purpose I/O pin 7. Configurable as input or output. 16 VDD Power Positive supply voltage pin. Typically 2.3V to 5.5V. 17 NC No Connect No connection. Can be left floating. 18 NC No Connect No connection. Can be left floating. 19 NC No Connect No connection. Can be left floating. 20 NC No Connect No connection. Can be left floating.20 FAQs Regarding TCA9535PWR Pin Functions:
Q: What is the purpose of the RESET pin in TCA9535PWR? A: The RESET pin is an active-low reset input. It is used to reset the device and restore it to its default state.
Q: Can the TCA9535PWR be powered from a 5V supply? A: Yes, the TCA9535PWR can operate with a supply voltage ranging from 2.3V to 5.5V.
Q: How many I/O pins are available on the TCA9535PWR? A: The TCA9535PWR has 8 configurable I/O pins, labeled P0.0 to P0.7.
Q: What type of communication does TCA9535PWR use? A: TCA9535PWR uses I2C communication for interfacing with a microcontroller or other devices.
Q: How do the address pins A0, A1, and A2 work? A: The address pins A0, A1, and A2 define the I2C address of the device, with each pin representing one bit of the address.
Q: What happens if the A0, A1, and A2 pins are left unconnected? A: If these pins are left unconnected, the device will use the internal pull-up resistors to determine the I2C address.
Q: How is the SDA pin used? A: The SDA pin is the Serial Data Line, used for transmitting and receiving data between the TCA9535PWR and the I2C master device.
Q: How is the SCL pin used? A: The SCL pin is the Serial Clock Line, used for generating the clock signal for I2C communication.
Q: What is the significance of the NC pins on the TCA9535PWR? A: The NC pins (Pins 17-20) are not connected to any internal circuitry and can be left floating.
Q: Can the TCA9535PWR be used to expand I/O on a microcontroller? A: Yes, the TCA9535PWR is specifically designed to expand I/O capabilities in microcontroller-based systems.
Q: Is there a maximum limit for the number of devices connected to the I2C bus? A: The maximum number of TCA9535PWR devices on an I2C bus is determined by the available addresses and the bus capacitance.
Q: What is the power consumption of the TCA9535PWR? A: Power consumption is relatively low, typically in the range of a few milliamps, depending on the operating conditions.
Q: Can the I/O pins of the TCA9535PWR be used as both inputs and outputs? A: Yes, the I/O pins of the TCA9535PWR are configurable as either input or output.
Q: What is the purpose of the VSS pin? A: The VSS pin is the ground pin of the device, providing the reference for the power supply.
Q: How should the TCA9535PWR be mounted on a PCB? A: The TCA9535PWR should be placed in a standard TSSOP-20 footprint on the PCB, with attention to proper routing for the I2C lines.
Q: Does the TCA9535PWR support interrupt functionality? A: Yes, the TCA9535PWR supports interrupt functionality for I/O state changes.
Q: Can the TCA9535PWR be reset during operation? A: Yes, it can be reset by applying a low signal to the RESET pin.
Q: What is the recommended pull-up resistor value for the I2C bus? A: Typically, 4.7kΩ pull-up resistors are used on the SDA and SCL lines.
Q: What voltage should be applied to the VDD pin? A: The VDD pin should be connected to a supply voltage in the range of 2.3V to 5.5V.
Q: Can the TCA9535PWR be used in a 3.3V system? A: Yes, the TCA9535PWR is compatible with 3.3V systems as long as the supply voltage is within the specified range.
This explanation covers all the pins, their functions, and frequently asked questions related to the TCA9535PWR I/O expander from Texas Instruments.