SPI Isolator 2 Click Board™

How Does The SPI Isolator 2 Click Board™ Work?

The SPI Isolator 2 Click Board™ is based on the ISO7741, a high-performance quad-channel digital isolator capable of galvanic isolation up to 5000Vrms from Texas Instruments. It provides high electromagnetic immunity and low emissions at low power consumption while isolating digital I/Os. It has three forward and one reverse-direction channel and provides a simple, compact solution for isolated SPI data communication. Each isolation channel has a logic input and output buffer separated by a double capacitive silicon dioxide insulation barrier.

The ISO7741 digital isolator use single-ended CMOS-logic switching technology and transmit the digital data across the isolation barrier. The transmitter sends a high-frequency carrier across the isolation barrier to represent one digital state and sends no signal to represent the other digital state. The receiver demodulates the signal after advanced signal conditioning and produces the output through a buffer stage. If the Enable pin is in a low logic state, then the output signal goes to a Hi-Z state.

The SPI Isolator 2 Click Board™ communicates with MCU using the SPI serial interface with a maximum data rate of 100 Mbps. This Click board™ also comes with two enable pins on each side, which can be used to put the respective outputs in a Hi-Z state for multi-master driving applications and reduce power consumption. The enable pin on the digital side of ISO7741, labeled as EN1, is routed on the RST pin of the mikroBUS™ socket, while the other Enable pin is connected to the external connector on the isolated side labeled as EN2.

In addition to the connectors to which the isolated SPI data communication lines are routed, this Click board ™ has another additional that represents an external power supply terminal. The voltage range is from 2.25 V to 5.5 V for both supplies logic and external, which makes it suitable for both 3.3V and 5V MCUs. The ISO7741 can also block high voltages, isolate grounds and prevent noise currents on a data bus or other circuits from entering the local ground and damaging sensitive circuitry.

The SPI Isolator 2 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 SPI 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.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout of the SPI Isolator 2 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
Enable	EN1	2	RST	INT	15	NC
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 2 CLICK ELECTRICAL SPECIFICATIONS