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The RoHS icon on this product indicates that the PCBs, components, solder, and chemicals are all lead-free and RoHS compliant. Additionally, this product is produced using a lead-free process. Unfortunately, we are currently unable to provide documentation confirming that this product is RoHS compliant.
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Package Includes:
This package does not include Din-Rail PCB holders and cables.
Notes:
- This board uses 4-pin, 2.0mm pin pitch connectors for I2C bus.
Features:
- PCF8574A I2C bus I/O expander
- 8 open-collector outputs
- Operating voltage: 2.5Vdc to 5.5Vdc
- On-board reverse polarity protection circuit
- 100kHz I2C Bus frequency
- Address selection via 3 jumpers(supports up to 8 addresses)
- Supports up to 16 boards on a single I2C bus
- Compatible with most microcontrollers
- Maximum load voltage: 50Vdc
- Rated Collector Current: 500mA(using a single output)
- Mountable on a DIN-Rail PCB Holder
- PCB dimensions: 42.50 x 72.00 mm
This is an I2C bus open-collector board designed as a remote 8-output expander via the I2C bus, based on the PCF8574A, making it an ideal open-collector expander for I2C applications. The board is compatible with most microcontrollers.
The PCF8574A is an I2C bus controller that receives commands from a microcontroller and drives the output ports. It supports a 100kHz I2C bus frequency and can be connected to the I2C port of most microcontrollers.
The board uses a ULN2803A chip as the output driver, providing 8 open-collector outputs. Each output has a maximum current rating of 500mA (when using a single output), but the total current across all outputs must not exceed 500mA. The maximum voltage rating for each output is 50Vdc.
The board’s I2C address is set using three jumpers, allowing for 8 unique addresses, so up to 8 boards can be connected on a single bus. Additionally, 16 boards can be connected on a single bus by using 8 boards with PCF8574 and 8 boards with PCF8574A, as these two ICs have different address ranges.
The board includes reverse polarity protection circuits to prevent damage due to incorrect power supply connections.
Difference Between I2C-OC805MA and I2C-OC805M
The I2C-OC805MA uses the PCF8574A.
The I2C-OC805M uses the PCF8574.
These two ICs 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 based on your specific use case.
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.
