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Package Includes:
Notes:
- This board uses 4-pin connectors for I2C bus.
Features:
- PCF8574 I2C bus I/O expander
- 8 open-collector outputs
- Operating voltage: 2.5V to 5.5V
- Reverse polarity protection circuit
- 100kHz I2C Bus frequency
- Address selection via 3 jumpers(supports up to 8 addresses)
- Support up to 16 boards on a single I2C bus
- Compatible with most microcontrollers
- Maximum load voltage: 50V
- Rated Collector Current: 500mA(using a single output)
- PCB dimensions 67 x 27mm
This is an I2C bus output board designed as a remote 8-output expander via the I2C bus, based on the PCF8574. It is called the I2C Output Board, making it an ideal open-collector expander for the I2C bus. The board is designed to be compatible with most microcontrollers.
The PCF8574 is an I2C bus controller that communicates with a microcontroller and receives commands to control the output ports. It supports a 100kHz I2C bus frequency and can be connected to the I2C port of most microcontrollers.
For output driving, the board uses the ULN2803A, which provides 8 open-collector outputs. Each output can handle a maximum current of 500mA (when using a single output) and a voltage of up to 50V.
The board's address is set using three jumpers, allowing up to 8 different addresses, so 8 boards can be connected on the same I2C bus. Additionally, 16 boards can be connected together by using 8 boards with PCF8574 and 8 boards with PCF8574A, as these two ICs have different address ranges.
The board includes a reverse polarity protection circuit to prevent damage from incorrect power supply connections. It also features an LED indicator to show the power supply status.
Difference Between I2C-OC805S and I2C-OC805SA
The I2C-OC805S uses the PCF8574, while the I2C-OC805SA uses the PCF8574A. These two chips have different I2C addresses.
Note: The power dissipation of the ULN2803A chip is an important factor for each application. You must calculate the power dissipation according to your specific usage.
Important Warning
To prevent damage to the board, do not plug or unplug I2C cables while the power supply is on. Always turn off the power supply before connecting or disconnecting I2C cables.
