ADC 15 Click Board

How Does The ADC 15 Click Board™ Work?

The ADC 15 Click Board™ as its foundation uses the ADS131M02, a low-power, two-channel, simultaneously sampling, 24-bit, delta-sigma (ΔΣ) analogue-to-digital converter (ADC) with a low-drift internal reference voltage from Texas Instruments. The dynamic range, size, feature set, and power consumption are optimized for cost-sensitive applications requiring simultaneous sampling. An integrated negative charge pump allows absolute input voltages as low as -1.3 V, which enables measurements of input signals varying around the ground with a single-ended power supply.

The ADS131M02 features a programmable gain amplifier (PGA) with gains up to 128. An integrated input pre-charge buffer enabled at gains greater than 4 ensures high input impedance at high PGA gain settings. The ADC receives its reference voltage from an integrated 1.2V reference, allowing differential input voltages as large as the reference. Each channel on the ADS131M02 contains a digital decimation filter that demodulates the output of the ΔΣ modulators. The filter enables data rates as high as 32 kSPS per channel in high-resolution mode. The relative phase of the samples can be configured between channels, thus allowing an accurate compensation for the sensor phase response. Offset and gain calibration registers can be programmed to adjust output samples for measured offset and gain errors automatically.

The ADC 15 Click Board™ communicates with MCU through a standard SPI interface to read the conversion data, configure and control the ADS131M02, supporting the most common SPI mode - SPI Mode 1. To normally run the ADS131M02, an LVCMOS clock must be continuously provided at the CLKIN pin, which is achieved with the LTC6903 programmable oscillator activated via the CS2 pin routed to the PWM pin on the mikroBUS™ socket. The frequency of the clock can be scaled in conjunction with the power mode to provide a trade-off between power consumption and dynamic range. Selection of the bits in the CLOCK register allows the device to be configured in one of three power modes: high-resolution (HR) mode, low-power (LP) mode, and very low-power (VLP) mode.

In addition, the ADC 15 Click Board™ also uses features such as data-ready/interrupt routed to the INT pin on the mikroBUS™ socket, that serves as a flag to the host to indicate that new conversion data are available, and Reset routed to the RST pin that allows for a hardware device reset.

The ADC 15 Click Board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout of the ADC 15 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	CS2	LTC6903 Enable
Reset	RST	2	RST	INT	15	INT	Data-Ready / Interrupt
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

ADC 15 CLICK ELECTRICAL SPECIFICATIONS