GainAMP 3 Click Board™

Product Code: MIKROE-4800

How Does The GainAMP 3 Click Board™ Work? The GainAMP 3 Click Board™ as its foundation uses the ADA4254, a zero drift, high voltage, programmable gain instrumentation amplifier (PGIA) designed for process control and industrial applications from Analog Devices. It accurately measures sensors, voltages, and currents with wide dynamic ranges and provides safety information about what is being measured. It features 12 binary weighted gains ranging from 1/16V/V to 128V/V and three scaling gain options of 1V/V, 1.25V/V, and 1.375V/V, resulting in 36 possible gain settings. Its zero-drift amplifier topology self-calibrates DC errors and low-frequency noise, achieving excellent DC precision over the entire specified temperature range, maximizing dynamic range, and significantly reducing calibration requirements in many applications. The ADA4254 communicates with MCU using the standard SPI serial interface with a maximum frequency of 5MHz, supporting the most common SPI mode, SPI Mode 0. It comes with a 4-channel input multiplexer providing ±60V protection to the high impedance inputs of the amplifier and an excitation current source output available to bias sensors such as resistance temperature detectors (RTDs).

In addition to these channels located on the onboard 9-pole connector, the ADA4254 also has a differential output stage and output excitation current channels. A differential output stage allows the device to be directly connected to high-precision ADCs. When making such a connection, it is recommended to use a low-pass filter before a connection to the ADCs to minimize noise and aliasing. A software configurable excitation current outputs can be used to excite external circuitry, such as resistive bridges or RTD sensors, and be programmed to a value from 100μA to 1.5mA in increments of 100μA. The GainAMP 3 Click Board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. In addition to choosing the logic voltage level using jumper labelled as DIGI, it is also possible to select the supply voltage of the amplifier using the AN jumper by positioning SMD jumpers to an appropriate position. This way, it is allowed for both 3.3V and 5V capable MCUs to use the SPI 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 Type Amplifier Applications Can be used for industrial systems and process control that demand precision, robustness, and low power, thanks to its low power consumption On-board modules ADA4254 - zero drift, high voltage, programmable gain instrumentation amplifier (PGIA) designed for process control and industrial applications from Analog Devices Interface SPI Compatibility mikroBUS Click board size L (57.15 x 25.4 mm) Input Voltage 3.3V or 5V, External Pinout Diagram This table shows how the pinout on the GainAMP 3 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 NC 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 Label Name Default Description LD1 PWR - Power LED Indicator JP1 VCC SEL-DIGI Left Logic Voltage Level Selection 3V3/5V: Left position 3V3, Right position 5V JP2