SPI Isolator 3 Click

How does it work?

SPI Isolator 3 Click as its foundation uses the MAX14483, a 6-channel 3.75kVRMS digital isolator with a very low propagation delay on the SDI, SDO, and SCLK channels from Analog Devices. It provides galvanic isolation for digital signals transmitted between two ground domains. The device withstands up to 560Vpeak of continuous isolation and up to 3.75kVRMS for up to 60 seconds. The wide supply voltage range of both power pins allows the MAX14483 to be used for level translation and isolation.

The MAX14483 offers low-power operation, high electromagnetic interference immunity, and stable temperature performance through Maxim’s proprietary process technology. The device isolates different ground domains and blocks high-voltage/high-current transients from sensitive or human interface circuitry. It also features an internal refresh circuit to ensure output accuracy when an input remains in the same state indefinitely.

SPI Isolator 3 Click communicates with MCU using the SPI serial interface with a maximum data rate of 200 Mbps. This Click board™ also comes with a SDO line enable control pin, labeled as OEN and routed on the RST pin of the mikroBUS™ socket, allowing MAX14483 to isolate multiple SPI devices. It also has a red LED indicator labeled as FLT to detect error outputs from other devices.

Besides an auxiliary channel, labeled as AUX, available for passing timing or control signals from the master side to the slave side, the MAX14483 also possesses power monitors for both power domains to signal if the opposite side of the isolator is ready for operation. The FLT and AUX channels are designed to support SPI devices that require control signals beyond the standard 4-wire SPI bus. Each channel is unidirectional; it only passes data in one direction with a maximum data rate of 25Mbps.

The monitor channels (SAA, SBA) are designed to pass DC signals and have significantly lon­ger propagation delays than other channels, meaning they should not be used for data signals. SAA and SBA are set high when their respective opposite side of the isolator has power and is operating normally. When Side A or Side B is not powered, SAA or SBA is set low, and all outputs are set to their default state.

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

Specifications

Pinout diagram

This table shows how the pinout on SPI Isolator 3 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Power Monitoring	SAA	1	AN	PWM	16	AUX	Auxiliary Signal for Timing or Control
SPI SDO Signal Enable	OEN	2	RST	INT	15	FLT	Interrupt
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

SPI Isolator 3 Click electrical specifications

Software Support

We provide a library for the SPI Isolator 3 Click as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Package can be downloaded/installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on mikroE github account.

Library Description

This library contains API for SPI Isolator 3 Click driver.

Key functions:

• spiisolator3_cfg_setup – Config Object Initialization function.
• spiisolator3_init – Initialization function.
• spiisolator3_default_cfg – Click Default Configuration function.

Examples description

This library contains API for the SPI Isolator 3 click driver. This demo application shows an example of an SPI Isolator 3 click wired to the nvSRAM 4 click for reading Device ID.

The demo application is composed of two sections :

void application_task ( void ) {
    get_device_id( );
    log_printf( &logger, " Device ID : 0x%.8LXrn", device_id ); 
    Delay_ms( 1000 );
}

Additional Function

• get_device_id – Get Device ID function.

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended way), downloaded from our LibStock™ or found on mikroE github account.

Other mikroE Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.SpiIsolator3

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click 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

This 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.

For more information about mikroSDK, visit the official page.