GainAMP Click

How does it work?

GainAMP Click is based on the LTC6912, a dual programmable gain amplifier with a serial digital interface from Analog Devices. The amplifier features low noise, rail-to-rail input range, rail-to-rail output swing, total system dynamic range of up to 115dB, low power hardware shutdown, and a single or dual power supply of 2.7V up to 10.5V. It consists of 2 matching amplifiers with rail-to-rail outputs, which process rail-to-rail input signals when operated with unity gain. A half-supply reference generated internally at the AGND pin supports single power supply applications.

GainAMP Click is equipped with voltage supply terminals labeled V+ and V-, which can supply the amplifier with voltage. A few solder jumpers are available for you to set the input voltage to a V+ and a V- rail. Over the V+ VCC jumper, you can choose the V+ voltage rail, while over the V- GND, you can choose the V- rail. The VCC and the GND are set by default, which means 3.3V or 5V is chosen over the 3V3 5V jumper. The 3.3V is also set by default. If you want to use an external voltage supply, you need to set jumpers to V+ and V-.

The analog inputs and outputs are available over the INA, OUTA, INB, and OUTB screw terminals. There is an unsoldered jumper header aside from the screw terminals, which can allow you to read the analog values of the A channel output only.

GainAMP Click uses a 3-Wire SPI serial interface to communicate with the host MCU. The RST pin is actually a shutdown pin of the amplifier and serves as a reset pin. The channel A output values can be read over the AN pin if the jumper header is connected.

This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the 3V3 5V jumper. This way, both 3.3V and 5V capable MCUs can use the 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 GainAMP Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Channel A Analog Input	AN	1	AN	PWM	16	NC
Reset	RST	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

GainAMP Click electrical specifications

Software Support

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

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

Library Description

This library contains API for GainAMP Click driver.

Key functions

• gainamp_read_an_pin_value GainAMP read AN pin value function.

• gainamp_read_an_pin_voltage GainAMP read AN pin voltage level function.

• gainamp_set_gain Function for sets gain of the GainAMP Click.

Example Description

This is an example that demonstrates the use of the GainAMP Click board.

 void application_task ( void ) 
 { 
     gainamp_set_gain( &gainamp, GAINAMP_CHANNEL_A_x1 | GAINAMP_CHANNEL_B_x5 ); 
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 ); 

     gainamp_set_gain( &gainamp, GAINAMP_CHANNEL_A_x10 | GAINAMP_CHANNEL_B_x100 ); 
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 );
     Delay_ms ( 1000 ); 
 }

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

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.GainAMP

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. UART terminal is available in all MIKROE compilers.

mikroSDK

This Click board™ is supported with mikroSDK – MIKROE 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.