ADC 9 Click Board

How Does The ADC 9 Click Board™ Work?

The MCP3564 24-bit Delta-Sigma Analog-to-Digital Converter is fully configurable with Oversampling Ratio (OSR) from 32 to 98304 and gain from 1/3x to 64x. It include an internal sequencer (SCAN mode) with multiple monitor channels and a 24-bit timer to be able to automatically create conversion loop sequences without needing MCU communications. Advanced security features, such as CRC and register map lock, can ensure configuration locking and integrity, as well as communication data integrity for secure environments.

The ADC 9 Click Board™ comes with a 20 MHz SPI-compatible serial interface. Communication is largely simplified with 8-bit commands, including various Continuous Read/Write modes and 24/32-bit multiple data formats that can be accessed by the Direct Memory Access (DMA) of an 8-bit, 16-bit or 32-bit MCU.

The noise value generally increases when temperature is higher as thermal noise is dominant for all OSR larger than 32. For high OSR settings (> 512), the thermal noise is largely dominant and increases proportionally to the square root of the absolute temperature. The noise performance is also a function of the measurement duration. For short duration measurements (low number of consecutive samples), the peak-to-peak noise is usually reduced because the crest factor (ratio between the RMS noise and peak-to-peak noise) is reduced. This is only a consequence of the noise distribution being Gaussian by nature.

The ADC 9 Click Board™ uses the MCP3564 IC with a fully configurable analog input dual multiplexer that can select which input is connected to each of the two differential input pins (VIN+/VIN-) of the Delta-Sigma ADC. Each of these multiplexers includes the same possibilities for the input selection, so that any required combination of input voltages can be converted by the ADC. The analog multiplexer is composed of parallel low-resistance input switches turned on or off depending on the input channel selection. Their resistance is negligible compared to the input impedance of the ADC (caused by the charge and discharge of the input sampling capacitors on the VIN+/VIN- ADC inputs).

The ADC 9 Click Board™ also features MCP1501-20, a low drift bandgap-based voltage reference from Microchip for precision data acquisition systems. The bandgap uses chopper-based amplifiers, effectively reducing the drift to zero.

It is designed to be operated only with 3.3V logic levels. A proper logic voltage level conversion should be performed before the ADC 9 Click Board™ is used with MCUs with logic levels of 5V.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout on the ADC 9 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	MCK	Master Clock
NC	2	RST	INT	15	INT	Interrupt/Modulator Data
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	NC
Ground	GND	8	GND	GND	9	GND	Ground

ONBOARD SETTINGS AND INDICATORS