ADC 21 Click Board™

Product Code: MIKROE-5531

How Does The ADC 21 Click Board™ Work? The ADC 21 Click Board™ is based on the ADC1283, a high-performance eight-channel analogue-to-digital converter from STMicroelectronics. The ADC1283 implements a successive approximation register (SAR) structure to convert analogue signals into 12-bit pure binary digital outputs. The conversion circuit includes a fast settling time comparator to convey instruction into the register to store digital 0 or 1 and a redistribution DAC with logic control to have the ADC compare the track signal with a reference signal at each clock cycle. The ADC 21 Click Board™ communicates with MCU through a standard SPI interface and operates at clock rates up to 3.2MHz, for all configurations and acquiring conversion results. The AD conversion is carried out in two phases. The sampling phase conveys the input signal through the capacitance array for the first three clock cycles. Then, the evaluation phase converts into a digital 12-bit signal within 13 clock cycles.

At each clock cycle of the evaluation phase, the hold signal is compared with a new value distributed by the DAC, and the result is stored in the 12-bit register, with MSB first. A complete conversion requires 16 clock cycles to generate a new 12-bit word on the SDO pin on the mikroBUS™ socket. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the communication lines properly. Additionally, there is a possibility for the ADC1283 analogue power supply selection via jumper labelled AVCC SEL to supply the ADC1283 from an external power supply in the range from 2.7V to 5.5V or with mikroBUS™ power rails. However, the ADC 21 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 ADC Applications It can be used for the most demanding applications, from general-purpose remote data acquisition and instrumentation to industrial applications On-board modules ADC1283 - eight-channel analog-to-digital converter from STMicroelectronics Key Features Low power consumption, high accuracy, high-speed serial interface, high performance, selectable conversion rate, 12-bit SAR-based ADC, selectable analogue power supply, and more Interface SPI Compatibility mikroBUS Click board size M (42.9 x 25.4 mm) Input Voltage 3.3V or 5V PINOUT DIAGRAM This table shows how the pinout of the ADC 21 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 Left Logic Level Voltage Selection 3V3/5V: Left position 3V3, Right position 5V JP2 AVCC SEL Left Analog Power Supply Selection VCC/VEXT: Left position VCC, Right position VEXT J1 - Populated Analog Input Channels Header ADC 21 CLICK ELECTRICAL SPECIFICATIONS Description Min Typ Max Unit