I2C Isolator 3 Click Board
I2C Isolator 3 Click Board
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.
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 |
Software Support
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.
Library Description
The library covers all the necessary functions to control the I2C Isolator 3 Click Board™. The library performs a standard I2C interface communication.
Key Functions
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.
Example Description
The application is composed of three sections :
- System Initialization - Initializes I2C and start to write log.
- Application Initialization - Initialization driver enables - I2C, set set I2C slave address of the Thermo 20 Click board™, performs software reset, also write log.
- Application Task - (code snippet) This example demonstrates using the I2C Isolator 3 Click board™. In this example, we measure temperature from the Thermo 20 Click board™ connected to the I2C Isolator 3 Click board™. All data logs write on USB UART changes every 3 sec.
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:
- I2C
- UART
- Conversions
Additional Notes and Information
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.
MIKROSDK
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.
Software Support
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.
Library Description
The library covers all the necessary functions to control the I2C Isolator 3 Click Board™. The library performs a standard I2C interface communication.
Key Functions
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.
Example Description
The application is composed of three sections :
- System Initialization - Initializes I2C and start to write log.
- Application Initialization - Initialization driver enables - I2C, set set I2C slave address of the Thermo 20 Click board™, performs software reset, also write log.
- Application Task - (code snippet) This example demonstrates using the I2C Isolator 3 Click board™. In this example, we measure temperature from the Thermo 20 Click board™ connected to the I2C Isolator 3 Click board™. All data logs write on USB UART changes every 3 sec.
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:
- I2C
- UART
- Conversions
Additional Notes and Information
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.
MIKROSDK
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.
I2C Isolator 3 Click Board
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