DAC 8 Click

How does it work?

DAC 8 Click is based on the DAC8554IPWR, a 16-bit QUAD channel, ultra-low glitch, voltage-output digital to analog converter from Texas Instruments. It offers good linearity, exceptionally low glitch, and it has high precision output amplifier that allows rail-to-rail output swing over a wide range of supply voltage. What this component additionally has is a Power-On reset function, which ensures that DAC outputs power-up at zero-scale and remains there until a proper write operation occurs. Also, it provides a power-down feature that reduces the current consumption to 175nA per channel.

To achieve a fully flexible range of the DAC8554IPWR, an external voltage reference is made user-programmable. For this purpose, the Click board™ uses another DAC, DAC60501MDGSR, 12-bit DAC from Texas Instruments, whose output is brought to the VREF pin of the DAC8554IPWR. That way, the reference voltage of the DAC8554IPWR can be set at any value between 0V and 5V, provides high precision and low power consumption as well. That makes the DAC 8 Click fully customizable solution, well suited for applications where the maximum precision from the output 16-bit DAC is needed. DAC60501MDGSR uses the I2C serial interface to communicate with the MCU and operates at clock rate up to 100kHz, with selectable I2C address through ADDR SEL jumper.

The DAC 6 Click communicates with MCU using the 3-Wire SPI serial interface that is compatible with standard SPI, QSPI™, MICROWIRE™ and operates at clock rates up to 50 MHz. Additional functionality such as software simultaneous update capability is implemented and routed at the PWM pin of the mikroBUS™, which allows when new data enter the device, all of DAC outputs can be updated simultaneously and synchronously with the clock. It also possesses enable function routed at CS pin of the mikroBUS™ that is used to connect the SPI interface to the serial port.

This Click Board™ is designed to be operated with both 3.3V and 5V logic levels. The onboard SMD jumper labeled as VCC SEL allows voltage selection for interfacing with both 3.3V and 5V MCUs. More information about the DAC8554IPWR’s functionality, electrical specifications, and typical performance can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy-to-use functions, and a usage example that can be used as a reference for the development.

Specifications

Pinout diagram

This table shows how the pinout on DAC Click 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	LD	Software Update
SPI Enable	EN	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	SCL	I2C Clock
SPI Data IN	SDI	6	MOSI	SDA	11	SDA	I2C Data
Power Supply	3.3V	7	3.3V	5V	10	5V	Power Supply
Ground	GND	8	GND	GND	9	GND	Ground

Onboard settings and indicators

DAC 8 Click electrical specifications

Software Support

DAC 8 Click demo application is developed using the NECTO Studio, ensuring compatibility with mikroSDK‘s open-source libraries and tools. Designed for plug-and-play implementation and testing, the demo is fully compatible with all development, starter, and mikromedia boards featuring a mikroBUS™ socket.

Example Description

This Click carries 12-bit buffered Digital-to-Analog Converter. It converts digital value to the corresponding voltage level using external voltage reference.

Key Functions

• dac8_cfg_setup Config Object Initialization function.
• dac8_init Initialization function.
• dac8_device_config output digital-to-analog converter on DAC 8 Click board.
• dac8_load_dac buffers of all channels must be loaded with desired data before call Load DAC function.
• dac8_set_vref With Precision Internal Reference on DAC 8 Click board.

Application Init

Initialization driver enables – I2C. Configure DAC60501: executes call software reset, disable sync and internal reference and disable Power-down mode, the set reference voltage is internally divided by a factor of 2, amplifier for corresponding DAC has a gain of 2. Initialization driver enables – SPI, enable DAC8554, also write log.

Application Task

This is an example that demonstrates the use of the DAC 8 Click board. DAC 8 board changeing output values: Channel A ~ 2500 mV, Channel B ~ 1250 mV, Channel C ~ 625 mV, Channel D ~ 312 mV. All data logs write on USB uart changes every 5 sec.

Application Output

This Click board can be interfaced and monitored in two ways:

• Application Output – Use the “Application Output” window in Debug mode for real-time data monitoring. Set it up properly by following this tutorial.
• UART Terminal – Monitor data via the UART Terminal using a USB to UART converter. For detailed instructions, check out this tutorial.

Additional Notes and Information

The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.