# Title: I2C Isolator 3 Click Board™ ## Description: How Does The I2C Isolator 3 Click Board™ Work? The I2C Isolator 3 Click Board™ 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. After a transient interruption on either side, the buffered signals will always return to their proper value. Unlike competitive magnetically isolated digital isolators, transformers, or capacitive isolators, the CPC5902 doesn't need to be clocked periodically to sustain the logic states. Besides, it offers glitch-free operation, excellent reliability, and a 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, buffering and isolating 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. The I2C Isolator 3 Click Board™ 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, corresponding to a 400 kbps transfer rate for the I2C bus. It also possesses two terminals labelled 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. The I2C Isolator 3 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 containing functions and an example code that can be used as a reference for further development. SPECIFICATIONS Type I2C, Isolators Applications Can be used 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 is also suitable as an I2C bus length extender and logic-level translator. On-board modules CPC5902 - a dual optically isolated bidirectional logic-bus repeater from IXYS Integrated Circuits Division Key Features The optically isolated bidirectional logic-bus repeater supports I2C clock stretching. It offers glitch-free operation, excellent reliability, and a very long operational life. Interface I2C Compatibility mikroBUS Click board size S (28.6 x 25.4 mm) Input Voltage 3.3V or 5V PINOUT DIAGRAM This table shows how the pinout of the I2C Isolator 3 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes Pin Pin Notes NC 1 AN PWM 16 NC NC 2 RST INT 15 NC NC 3 CS RX 14 NC NC 4 SCK TX 13 NC NC 5 MISO SCL 12 SCL I2C Clock NC 6 MOSI SDA 11 SDA I2C Data Power Supply 3.3V 7 3.3V 5V 10 5V Power Supply Ground GND 8 GND GND 9 GND Ground ONBOARD SETTINGS AND INDICATORS Label Name Default Description LD1 PWR - Power LED Indicator JP1 VCC SEL Left Logic Level Voltage Selection 3V3/5V: Left position 3V3, Right position 5V I2C ISOLATOR 3 CLICK ELECTRICAL SPECIFICATIONS Description Min Typ Max Unit Logic Level Supply Voltage 3.3 - 5 V Operating Supply Voltage 2.7 - 5.5 V Isolation Voltage 3750 - - Vrms I2C Clock Frequency 0 - 500 kHz Operating Temperature Range -40 25 +85 °C ## Product type: Click Board ## Vendor: Mikroelektronika d.o.o. ## Tags: Click Board, I2C, Interface, Isolated, Isolator, IXYS, MikroE, Serial Interface ## Price range: 9.8 - 9.8 GBP ## Link: https://thedebugstore.com/products/mikroe-4467-i2c-isolator-3-click-board-uk ## Compare-at price range: 14.0 - 14.0 GBP ## Options - Title: Default Title ## Collections - [New Products](https://thedebugstore.com/a/llms/collections/new-products-debug-store) - [Mikroelektronika d.o.o. 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The I2C Isolator 2 Click Board™ provides I2C lines and power isolation for slave devices. It carries the ADM3260 dual I2C isolator with an integrated DC-to-DC converter. I2C Isolator 2 Click Board™ is designed to run on either 3.3V or 5V power supply.
The Click Board™ communicates with the target microcontroller over an I2C interface with additional functionality provided by the PWM pin on the MikroBUSline.
- amazon_main_image: https://www.thedebugstore.com/images/product/lg-i2c-isolator-click-board.jpg - amazon_nl_currency: EUR - amazon_nl_price: 23.8656 - amazon_prime_enable: FALSE - amazon_product_id: 8606018710416 - amazon_product_id_type: EAN - amazon_product_type: computercomponent - amazon_search: MikroElektronika Microelectronica MIKROE-1100 - amazon_se_curency: SEK - amazon_se_price: 240.768 - amazon_short_description: The I2C Isolator 2 Click Board™ provides I2C lines and power isolation for slave devices. It carries the ADM3260 dual I2C isolator with an integrated DC-to-DC converter. I2C Isolator 2 Click Board™ is designed to run on either 3.3V or 5V power supply.The Click Board™ communicates with the target microcontroller over an I2C interface with additional functionality provided by the PWM pin on the MikroBUSline. - amazon_title: I2C Isolator 2 Click Board - amazon_uk_currency: GBP - amazon_uk_price: 21.12 - amazon_update: Update - description_tag: The I2C Isolator 3 Click Board™ 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. Available from Debug Store UK. - title_tag: MikroE I2C Isolator 3 Click Board™ (MIKROE-4467) - backorder_label: If no stock shown above, check availability - full_description:The I2C Isolator 3 Click Board™ 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. After a transient interruption on either side, the buffered signals will always return to their proper value. Unlike competitive magnetically isolated digital isolators, transformers, or capacitive isolators, the CPC5902 doesn't need to be clocked periodically to sustain the logic states. Besides, it offers glitch-free operation, excellent reliability, and a 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, buffering and isolating 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.
The I2C Isolator 3 Click Board™ 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, corresponding to a 400 kbps transfer rate for the I2C bus. It also possesses two terminals labelled 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.
The I2C Isolator 3 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 containing functions and an example code that can be used as a reference for further development.
| Type | I2C, Isolators |
| Applications | Can be used 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 is also suitable as an I2C bus length extender and logic-level translator. |
| On-board modules | CPC5902 - a dual optically isolated bidirectional logic-bus repeater from IXYS Integrated Circuits Division |
| Key Features | The optically isolated bidirectional logic-bus repeater supports I2C clock stretching. It offers glitch-free operation, excellent reliability, and a very long operational life. |
| Interface | I2C |
| Compatibility | mikroBUS |
| Click board size | S (28.6 x 25.4 mm) |
| Input Voltage | 3.3V or 5V |
This table shows how the pinout of the I2C Isolator 3 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).
| Notes | Pin | ![]() |
Pin | Notes | |||
|---|---|---|---|---|---|---|---|
| NC | 1 | AN | PWM | 16 | NC | ||
| NC | 2 | RST | INT | 15 | NC | ||
| NC | 3 | CS | RX | 14 | NC | ||
| NC | 4 | SCK | TX | 13 | NC | ||
| NC | 5 | MISO | SCL | 12 | SCL | I2C Clock | |
| NC | 6 | MOSI | SDA | 11 | SDA | I2C Data | |
| Power Supply | 3.3V | 7 | 3.3V | 5V | 10 | 5V | Power Supply |
| Ground | GND | 8 | GND | GND | 9 | GND | Ground |
| Label | Name | Default | Description |
|---|---|---|---|
| LD1 | PWR | - | Power LED Indicator |
| JP1 | VCC SEL | Left | Logic Level Voltage Selection 3V3/5V: Left position 3V3, Right position 5V |
| Description | Min | Typ | Max | Unit |
|---|---|---|---|---|
| Logic Level Supply Voltage | 3.3 | - | 5 | V |
| Operating Supply Voltage | 2.7 | - | 5.5 | V |
| Isolation Voltage | 3750 | - | - | Vrms |
| I2C Clock Frequency | 0 | - | 500 | kHz |
| Operating Temperature Range | -40 | 25 | +85 | °C |
We provide a library for the I2C Isolator 3 Click Board™ on our LibStock page and a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.
The package can be downloaded/installed directly from NECTO Studio The package Manager (recommended), downloaded from our LibStock™ or found on the mikroE Github account.
The library covers all the necessary functions to control the I2C Isolator 3 Click Board™. The library performs a standard I2C interface communication.
void i2cisolator3_set_slave_address ( uint8_t slave_addr ) - Set slave address function.void i2cisolator3_send_cmd ( uint8_t command ) - Send command function.void i2cisolator3_burst_read ( uint8_t reg, uint8_t *p_rx_data, uint8_t n_bytes ) - Burst read function.The application is composed of three sections :
void application_task ( )
{
i2cisolator3_send_cmd( I2CISOLATOR3_THERMO20_CMD_CONVERSION );
Delay_ms( 100 );
calculate_temperature( );
FloatToStr( temperature, log_text );
mikrobus_logWrite( " Temperature : ", _LOG_TEXT );
mikrobus_logWrite( log_text, _LOG_TEXT );
mikrobus_logWrite( " C", _LOG_LINE );
mikrobus_logWrite( "--------------------------", _LOG_LINE );
Delay_ms( 3000 );
}
Additional Functions :
void calculate_temperature( ) - Calculate temperature in degrees Celsius.The complete application code, and ready-to-use projects can be found on our LibStock page.
Other mikroE Libraries used in the example:
Depending on the development board you are using, you may need USB UART Click Board™, USB UART 2 Click Board™ or RS232 Click Board™ to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.
The I2C Isolator 3 Click Board™ is supported with mikroSDK - MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.
- attachments: [{"download_file":[{"download_file":"I2C Isolator 3 Click Board™ Schematic"}],"download_filetype":[{"download_filetype":"pdf"}]},{"download_file":[{"download_file":"IXYS CPC5902 Isolated I2C Bus Repeater Datasheet"}],"download_filetype":[{"download_filetype":"pdf"}]}] - device_vendor: IXYS Integrated Circuits Division - device_type: CPC5902G - warranty: 12 months - brand: MikroE - manufacturer: Mikroelektronika d.o.o. - target_keyword: I2C Isolator 3 Click Board - brands: gid://shopify/Metaobject/56256004319 - breadcrumbs: ["gid://shopify/Collection/447955239135","gid://shopify/Collection/241680580797","gid://shopify/Collection/241546100925"] - customhs_code: 847330 - detailed_description: {"type":"root","children":[{"type":"heading","level":3,"children":[{"type":"text","value":"How Does The I2C Isolator 3 Click Board™ Work?"}]},{"type":"paragraph","children":[{"type":"text","value":"The "},{"type":"text","value":"I2C Isolator 3 Click Board™","bold":true,"italic":true},{"type":"text","value":" 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. After a transient interruption on either side, the buffered signals will always return to their proper value. Unlike competitive magnetically isolated digital isolators, transformers, or capacitive isolators, the CPC5902 doesn't need to be clocked periodically to sustain the logic states. Besides, it offers glitch-free operation, excellent reliability, and a 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."}]},{"type":"paragraph","children":[{"type":"text","value":""}]},{"type":"paragraph","children":[{"type":"text","value":"This optically coupled I2C bus repeater is ideal for Power-over-Ethernet (PoE) applications, buffering and isolating 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."}]},{"type":"paragraph","children":[{"type":"text","value":"The "},{"type":"text","value":"I2C Isolator 3 Click Board™","bold":true},{"type":"text","value":" 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, corresponding to a 400 kbps transfer rate for the I2C bus. It also possesses two terminals labelled 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."}]},{"type":"paragraph","children":[{"type":"text","value":"The "},{"type":"text","value":"I2C Isolator 3 Click Board™","bold":true},{"type":"text","value":" 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 containing functions and an example code that can be used as a reference for further development."}]},{"type":"heading","level":3,"children":[{"type":"text","value":"SPECIFICATIONS"}]},{"type":"paragraph","children":[{"type":"text","value":"Type\nI2C, Isolators\nApplications\nCan be used 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 is also suitable as an I2C bus length extender and logic-level translator.\nOn-board modules\nCPC5902 - a dual optically isolated bidirectional logic-bus repeater from IXYS Integrated Circuits Division\nKey Features\nThe optically isolated bidirectional logic-bus repeater supports I2C clock stretching. It offers glitch-free operation, excellent reliability, and a very long operational life.\nInterface\nI2C\nCompatibility\nmikroBUS\nClick board size\nS (28.6 x 25.4 mm)\nInput Voltage\n3.3V or 5V"}]},{"type":"heading","level":3,"children":[{"type":"text","value":"PINOUT DIAGRAM"}]},{"type":"paragraph","children":[{"type":"text","value":"This table shows how the pinout of the "},{"type":"text","value":"I2C Isolator 3 Click Board™","bold":true},{"type":"text","value":" corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns)."}]},{"type":"paragraph","children":[{"type":"text","value":"Notes\nPin\nPin\nNotes\nNC\n1\nAN\nPWM\n16\nNC\nNC\n2\nRST\nINT\n15\nNC\nNC\n3\nCS\nRX\n14\nNC\nNC\n4\nSCK\nTX\n13\nNC\nNC\n5\nMISO\nSCL\n12\nSCL\nI2C Clock\nNC\n6\nMOSI\nSDA\n11\nSDA\nI2C Data\nPower Supply\n3.3V\n7\n3.3V\n5V\n10\n5V\nPower Supply\nGround\nGND\n8\nGND\nGND\n9\nGND\nGround"}]},{"type":"heading","level":3,"children":[{"type":"text","value":"ONBOARD SETTINGS AND INDICATORS"}]},{"type":"paragraph","children":[{"type":"text","value":"Label\nName\nDefault\nDescription\nLD1\nPWR\n-\nPower LED Indicator\nJP1\nVCC SEL\nLeft\nLogic Level Voltage Selection 3V3/5V: Left position 3V3, Right position 5V"}]},{"type":"heading","level":3,"children":[{"type":"text","value":"I2C ISOLATOR 3 CLICK ELECTRICAL SPECIFICATIONS"}]},{"type":"paragraph","children":[{"type":"text","value":"Description\nMin\nTyp\nMax\nUnit\nLogic Level Supply Voltage\n3.3\n-\n5\nV\nOperating Supply Voltage\n2.7\n-\n5.5\nV\nIsolation Voltage\n3750\n-\n-\nVrms\nI2C Clock Frequency\n0\n-\n500\nkHz\nOperating Temperature Range\n-40\n25\n+85\n°C"}]},{"type":"heading","level":3,"children":[{"type":"text","value":" "}]}]} - summary:The I2C Isolator 3 Click Board™ 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.
The I2C Isolator 3 Click Board™ is supported by a mikroSDK compliant library, which includes functions that simplify software development. This Click Board™ comes as a fully tested product, ready to be used on a system equipped with the mikroBUS™ socket.