- 1-to-8 Bidirectional Translating Switches
- Supports Hot Insertion
- Low Standby Current
- 1-to-8 Bidirectional Translating Switches
- Active-Low Reset Input
- Power Up With All Switch Channels Deselected
Description:
The TCA9548A 1-to-8 I2C 8 multi-channel expansion board enables communication with multiple I2C devices that have the same address making it simple to interface with. Using this you can get up to 8 same-address I2C devices hooked up to one microcontroller - this multiplexer acts as a gatekeeper, shuttling the commands to the selected set of I2C pins with your command. The CJMCU TCA9548A I2C 8 Channel Multiple extensions development board is interesting in that it has an I2C address (0x70 by default) – and you basically send it a command to tell it which I2C multiplexed output you want to talk to, then you can address the board you want to address.
Specification:
- Input Voltage: 1.6~5.5V
- Clock Frequency: 0~400kHz
Features:
- 1-to-8 Bidirectional Translating Switches
- Supports Hot Insertion
- Low Standby Current
- 1-to-8 Bidirectional Translating Switches
- Active-Low Reset Input
- Power Up With All Switch Channels Deselected
- I2C Bus and SMBus Compatible
- 5-V Tolerant Inputs
- Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II
Pin Description:
Power Pins:
- Vin – this is the power pin. Since the sensor chip uses 3-5 VDC. To power, the board, give it the same power as the logic level of your microcontroller – e.g. for a 5V micro like Arduino, use 5V.
- GND – common ground for power and logic.
I2C Control-Side pins :
- SCL – this is the I2C clock pin for the chip itself, connected to your microcontroller's I2C clock line.
- SDA – this is the I2C data pin for the chip itself, connected to your microcontroller's I2C data line.
- RST – this is the reset pin, for resetting the multiplexer chip. Pulled high by default, connect to ground to reset
- A0A1 A2 – these are the address selection pins for the multiplexer. By default, the multiplexer is at address 0x70 and these three pins are pulled low. Connect them to Vin to set the address to 0x71 – 0x77.
- A0 is the lowest-significant bit (if it is pulled high, it will increase the address by 1).
- A1 is the 2nd-lowest-significant bit (if it is pulled high, it will increase the address by 2).
- A2 is the 3rd-lowest-significant bit (if it is pulled high, it will increase the address by 4).
- SDx and SCx: There are 8 sets of SDx and SCx pins, from SD0/SC0 to SD7/SC7. These are the multiplexed pins. Each one is a completely separate I2C bus set. So you have 8 I2C devices with identical addresses, as long as they are on one I2C bus each.
- These pins do not have any pull-ups installed, so if you are using a chip or breakout without I2C pull-ups be sure to add them! Nicely, you can have Vin be 3.3V and have these pins pulled up to 5V (that is, they are 5V compliant).
Package Included:
1 x CJMCU-9548 TCA9548A 1-to-8 I2C 8-Channel IIC Multiplexer Multi-channel Expansion Development Board