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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:
- PCF8574 I2C bus I/O expander
- 8 open-collector outputs
- Operating voltage: 2.5Vdc to 5.5Vdc
- On-board reverse polarity protection circuits
- 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 PCF8574, making it an ideal open-collector expander for I2C applications. The board is compatible with most microcontrollers.
The PCF8574 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 for the output drivers, which provides 8 open-collector outputs. The maximum current rating for each output is 500mA (using a single output). However, 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, which allows for 8 different 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 for the power supply input voltage to prevent damage from incorrect connections.
Difference Between I2C-OC805M and I2C-OC805MA
The I2C-OC805M uses the PCF8574
The I2C-OC805MA uses the PCF8574A
These two ICs have different I2C addresses
Note: The power dissipation of the ULN2803A chip is an important consideration for each application. You must calculate the power dissipation based on 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.
