Power MUX 2 Click

How does it work?

Power MUX 2 Click as its foundation uses the TPS2120, a highly configurable power mux with an automatic switchover feature from Texas Instruments. This dual-input single-output power multiplexer prioritizes the main supply of 12V when present and quickly switches to an auxiliary supply of 5 V when the main supply drops. A priority voltage supervisor is used to select an input source. During switchover, the voltage drop is controlled to block reverse current before it happens and provide uninterrupted power to the load with minimal hold-up capacitance.

If one of the input power supplies were to fail, the system needs to automatically switchover to a backup power source without interrupting regular operation. When the 12V supply on IN1 drops below 7.6V, the device will automatically switch to the 5V auxiliary supply on IN2. When the 12V supply returns, it will become the output supply again. Furthermore, the voltage drop on the output should be minimal, providing the output with uninterrupted redundant power.

The Power MUX 2 Click communicates with MCU through the 3-Wire SPI serial interface using the TPL0501, an onboard 256-taps digital potentiometer from Texas Instruments. This way, the TPL0501 serves a current limiter that adjusts the output current of the TPS2120 instead of an external resistor. Current limiting can be used during Startup and switchover to protect against overcurrent events and protect the device during regular operation.

As an additional feature, this Click board™ also has two red LED indicators labeled as IN1 and IN2, which visually indicate to the user the fact which one of the two power supplies, IN1 or IN2, is located on the output more precisely on the output connector of the Click board, labeled as OUT.

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 properly use the SPI communication lines. 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 Power MUX 2 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
	NC	2	RST	INT	15	NC
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
	NC	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

Power MUX 2 Click electrical specifications

Software Support

We provide a library for the PowerMux2 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 PowerMux2 Click driver.

Key functions:

• powermux2_cfg_setup – Config Object Initialization function.
• powermux2_init – Initialization function.
• powermux2_default_cfg – Click Default Configuration function.

Examples description

This library contains API for the Power MUX 2 Click driver. The Power MUX 2 operates in automatic switchover mode with a priority prioritizing supply 1 when present and quickly switches to supply 2 when supply 1 drops below approximately 6V.

The application is composed of three sections :

void application_task ( void ) {
    log_printf( &logger, "--------------------------rn" );
    log_printf( &logger, " Resistance    ~ 100 kOhm rn" );
    log_printf( &logger, " Current Limit ~   1.23 A rn" );
    powermux2_set_resistance( &powermux2, 100 );
    Delay_ms( 5000 );
    
    log_printf( &logger, "--------------------------rn" );
    log_printf( &logger, " Resistance    ~  50 kOhm rn" );
    log_printf( &logger, " Current Limit ~   2.25 A rn" );
    powermux2_set_resistance( &powermux2, 50 );
    Delay_ms( 5000 );
}

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.PowerMux2

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.