I2C Isolator 3 Click is a compact add-on board that offers completely isolated bidirectional communication. This board features the CPC5902, a dual optically isolated bidirectional logic-bus repeater from IXYS Integrated Circuits Division. The CPC5902 pass DC signals and don’t need to be clocked periodically to sustain the logic states. It supports I2C clock stretching while providing 3750Vrms of galvanic isolation. When different supply voltages are applied on both power sides of the CPC5902, it can also function as a logic level translator for levels as low as 2.7V or as high as 5.5V. This Click board™ is ideal for Power-over-Ethernet applications, providing buffering and isolation of the clock and data signals between MCU and the Power Supply Equipment (PSE) controller, and also suitable as an I2C bus length extender and logic-level translator.

I2C Isolator 3 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

I2C Isolator 3 Click is based on the CPC5902, a dual optically isolated bidirectional logic-bus repeater from IXYS Integrated Circuits Division. It bidirectionally buffers the two I2C signals across the isolation barrier and supports I2C clock stretching while providing 3750Vrms of galvanic isolation. The buffered signals will always return to their proper value after a transient interruption on either side. Unlike competitive magnetically isolated digital isolators, transformer, or capacitive isolators, the CPC5902 doesn’t need to be clocked periodically to sustain the logic states. Besides, it offers glitch-free operation as well as excellent reliability and a very long operational life. If different supply voltage levels are used at each power supply side, it can also function as a logic level translator for levels as low as 2.7V or as high as 5.5V.

This optically coupled I2C bus repeater is ideal for Power-over-Ethernet (PoE) applications, providing buffering and isolation of the clock and data signals between the host controller and the Power Supply Equipment (PSE) controller. Additional applications include power supply high side interface, I2C bus length extender, and isolated signal monitoring and control. An extensive operational power supply range of 2.7V to 5.5V also enables I2C logic level translation applications.

I2C Isolator 3 Click communicates with MCU using the standard I2C 2-Wire interface and supports both Standard and Fast Mode with a transfer rate up to 400kbps. The CPC5902 is also fully compatible with any single or double wire bus in the frequency range from 0 Hz to 500 kHz, which corresponds to a 400 kbps transfer rate for the I2C bus. It also possesses two terminals labeled as VIN and I2C at the bottom of the Click board™, where VIN represents the B-side power supply of the repeater, while the other I2C corresponds to the isolated bidirectional logic-bus terminal.

This Click board™ is designed to operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. It allows for both 3.3V and 5V capable MCUs to use the I2C communication lines properly. However, the Click board™ comes equipped with a library that contains functions and an example code that can be used, as a reference, for further development.

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 28.6 x 25.4mm
• Input Voltage: 3.3V or 5V
• Logic Level Supply Voltage: Min. 3.3V, Max. 5V
• Operating Supply Voltage: Min. 2.7V, Max. 5.5V
• Isolation Voltage: 3750 Vrms
• I2C Clock Frequency: Min. 0kHz, Max. 500kHz
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +85°C

• Schematic
• CPC5902 Datasheet
• mikroSDK
• GitHub