MIKROE-2555

GainAMP click PID: MIKROE-2555 Weight: 25 g GainAMP click carries the LTC®6912 dual channel, low noise, digitally programmable gain amplifier (PGA). The click is designed to work on either 3.3V or 5V power supply. It communicates with the target MCU over SPI interface, with additional functionality provided by the following pins on the mikroBUS™ line: AN, RST. GainAMP click also features three pairs of screw terminals and a power indication LED. How it works The gains for both channels are independently programmable, using a 3-wire SPI interface to select voltage gains of 0, 1, 2, 5, 10, 20, 50, and 100V/V (LTC6912-1). All gains are inverting. The LTC®6912 consists of 2 matched amplifiers with rail-to-rail outputs. When operated with unity gain, they will also process rail-to-rail input signals. A half-supply reference generated internally at the AGND pin supports single power supply applications. Operating from single or split supplies from 2.7V to 10.5V total. Programmable gain amplifier A programmable-gain amplifier (PGA) is an electronic amplifier whose gain can be controlled externally (by analog or digital signals). Key features     LTC®6912 gain amplifier   o 2 Channels with Independent Gain Control  o 3‐Wire SPI Interface  o Extended Gain‐Bandwidth at High Gains  o Rail‐to‐Rail Input Range      o Rail‐to‐Rail Output Swing  o Single or Dual Supply: 2.7V to 10.5V Total  Screw terminals for input and output  SPI interface  3.3V or 5V power supply    Specification Product Type Amplifier Data Acquisition Systems, Dynamic Gain Changing, Automatic Ranging Applications Circuits, Automatic Gain Control. MCU LTC®6912 dual channel gain amplifier Rail-to-Rail Output Swing, Rail-to-Rail Input Range, 2 Channels with Key Features Independent Gain Control, Three pairs of screw terminals, 3-wire SPI interface Interface SPI Power Supply 3.3V or 5V Compatibility mikroBUS Click board S (28.6 x 25.4 mm) size 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  mikroBUStm  Analog input  AN_IN  1 AN  Shut down  SHDN  PWM 16 NC Not connected  2 RST Chip select  SPI_CS  3 INT  15 NC Not connected  CS  TX  14 NC Not connected  SPI Clock Input  SPI_CLK 4 SCK RX  13 NC Not connected  Not connected  5 MISO SCL 12 NC Not connected  SPI Master Output Slave Input  SPI_MOSI 6 MOSI SDA 11 NC Not connected  NC  Power supply  +3.3V  7 3.3V Ground  GND  8 GND 5V  10 +5V Power supply  GND 9 GND Ground  Maximum ratings Description  Min  Typ Max Unit Total Supply Voltage (V+ to V–)  11V V      Input Current  ±10 mA   Operating Temperature Range  –40°C  85°C Jumpers and settings Designator  Name  Default Position  Default Option Description  JP1  AN_sel  ON  AN  Analog input jumper. JP2  V+  Left  VCC  V+ selection.  JP3  V‐  Left  GND  V‐ selection.  Programming Code examples for GainAMP click, written for MikroElektronika hardware and compilers are available on Libstock. The gains for both channels are independently programmable using an SPI interface to select voltage gains. The example controls channel A, increasing and decreasing gain with input buttons. Code snippet The code snippet demonstrates a simple usage of the helper function. 01 void main() 02 { 03 system_init(); 04 05 gain_amp_set(GAIN_AMP_NOMINAL_0, GAIN_AMP_SW_SHUTDOWN); 06 07 while( 1 ) 08 { 09 if(Button(&GPIOE_IDR, 9, 100, 1)) 10 { 11 byte = gain_amp_set(++gain & 0x07, GAIN_AMP_SW_SHUTDOWN); 12 GPIOD_ODR = (GPIOD_ODR & 0xFF00) | byte; 13 } 14 if(Button(&GPIOE_IDR, 8, 100, 1)) 15 { 16 byte = gain_amp_set(--gain & 0x07, GAIN_AMP_SW_SHUTDOWN); 17 GPIOD_ODR = (GPIOD_ODR & 0xFF00) | byte; 18 } 19 } 20 }                                     https://shop.mikroe.com/click/audio‐and‐voice/gainamp  4/5/17