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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:
Notes:
- This board uses 5-pin connectors for I2C bus.
Features:
- PCF8574A I2C bus expander chip
- Supports 100kHz I2C bus frequency
- Selectable I2C bus pull-up resistors
- Addressable via 3 jumpers, supporting up to 8 addresses
- Supports connection of up to 16 boards on the same bus
- Interrupt output signal for event notification
- Selectable interrupt pull-up resistor
- Compatible with most microcontrollers
- 8 optically isolated digital input channels
- Accepts input voltage from 3.0Vdc to 30Vdc
- Supports input voltages greater than 30Vdc with external resistors
- 3700Vdc isolation input voltage
- Operating power supply voltage: 3.0V to 5.5V
- Inverse polarity protection circuits
- Compact board size: PCB size 28x81.5mm
This is an optocoupler I2C board designed as a remote 8-input expander for the I2C bus based on the PCF8574A. It serves as an ideal isolation input expander for the I2C bus and is compatible with microcontrollers operating between 3.0V to 5.5V.
The PCF8574A is the I2C bus expander chip that communicates with the microcontroller and reads the status of input voltages from the optocouplers. It supports a 100kHz bus frequency and can be connected to an I2C port of a microcontroller running at 3.0V to 5.5V. The I2C bus requires pull-up resistors for the SDA and SCL lines. The board includes these resistors, and they can be enabled or disabled via jumpers.
The board also features an interrupt output signal. This signal informs the microcontroller of incoming voltage on the inputs. The interrupt pin is open-drain, so it requires a pull-up resistor, which is included on the board and can be enabled or disabled using a jumper.
The board contains 8 optocouplers for input voltages. Each input supports high-level logic from 3.0Vdc to 30Vdc. While the inputs can handle voltages greater than 30Vdc, external resistors are required for higher voltages.
The board can be addressed using 3 jumpers, allowing for 8 different addresses. This enables up to 8 boards to be connected on the same I2C bus. Additionally, 16 boards can be connected on the same bus by assigning 16 unique addresses. This allows for the connection of eight PCF8574 boards and eight PCF8574A boards on the same bus, as the PCF8574 does not share the same address as the PCF8574A.
The board includes inverse polarity protection circuits to prevent damage caused by incorrect connections. An LED indicator is also provided to show the status of the power supply input voltage.
Designed for compactness, the board's PCB size is 28x81.5mm.
The I2C-IN830S and I2C-IN830SA models differ only in their I2C chips, which also results in different slave addresses. These models can replace the EI2C-9AG and EI2C-9AGA, respectively.
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 plugging or unplugging I2C cables on the board.
