SolidSwitch Click

How does it work?

SolidSwitch Click, as its foundation, uses the TPS22918, a 5.5V 2A load switch from Texas Instruments. To reduce voltage drop for low voltage and high current rails, every TPS22918 implements a low resistance N-channel MOSFET, reducing the drop-out voltage across the device. An ON/OFF input on the ON pin of the TPS22918 controls the switches. The ON pin is compatible with the standard GPIO logic threshold and can be used with any MCU with 1V or higher GPIO voltage. That’s why the control of all switches is established via the port expander, the MAX7323.

This Click board™ is designed to operate from an external supply voltage range from 1V to 5.5V. The TPS22918 works regardless of power sequencing order. The order in which voltages are applied to the VIN terminal and ON pin of the load switch will not damage the device as long as the voltages do not exceed the absolute maximum operating conditions.

SolidSwitch Click communicates with MCU through the MAX7323 port expander using the standard I2C 2-Wire interface with a frequency of up to 400kHz. It also has two address pins (A0 and A1) programmed by the user to determine the value of the last two LSBs of the slave address, selected by onboard SMD jumpers labeled as ADDR SEL to an appropriate position marked as 0 and 1, allowing selection of the slave address LSBs. Also, this Click board™ has a Reset pin, routed to the RST pin on the mikroBUS™ socket, which clears the serial interface in case of a bus lockup, terminating any serial transaction to or from the MAX7323.

Also, it uses an additional pin, the INT pin of the mikroBUS™ socket, which automatically flags data changes on any of the I/O ports of the MAX7323 used as inputs. The interrupt output INT and all transition flags are deasserted when the MAX7323 is accessed through the serial interface.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. 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

Pinout diagram

This table shows how the pinout on SolidSwitch Click 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
Reset	RST	2	RST	INT	15	INT	Interrupt
	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	NC
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

SolidSwitch Click electrical specifications

Software Support

We provide a library for the SolidSwitch 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 SolidSwitch Click driver.

Key functions:

• solidswitch_cfg_setup – Config Object Initialization function.
• solidswitch_init – Initialization function.
• solidswitch_default_cfg – Click Default Configuration function.

Examples description

This example demonstrates the use of SolidSwitch Click board™.

The demo application is composed of two sections :

void application_task ( void )
{
    solidswitch_write_single ( &solidswitch, SOLIDSWITCH_ENABLE_OUT0 | SOLIDSWITCH_ENABLE_OUT1 );
    solidswitch_display_enabled_channels( );
    Delay_ms ( 3000 );
    solidswitch_write_single ( &solidswitch, SOLIDSWITCH_ENABLE_OUT6 | SOLIDSWITCH_ENABLE_OUT7 );
    solidswitch_display_enabled_channels( );
    Delay_ms ( 3000 );
    solidswitch_write_single ( &solidswitch, SOLIDSWITCH_ENABLE_ALL_OUTPUTS );
    solidswitch_display_enabled_channels( );
    Delay_ms ( 3000 );
    solidswitch_write_single ( &solidswitch, SOLIDSWITCH_DISABLE_ALL_OUTPUTS );
    solidswitch_display_enabled_channels( );
    Delay_ms ( 3000 );
}

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.SolidSwitch

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.