DAC 9 Click

How does it work?

DAC 9 Click is based on the DAC80501, a single-channel, buffered, 16-bit resolution digital-to-analog converter from Texas Instruments. It includes a 2.5V, 5ppm/˚C internal reference, giving full-scale output voltage ranges of 1.25V, 2.5V, or 5V, and incorporates a Power-On Reset function. This function makes sure that the DAC80501 output powers up at zero scale or midscale and remains at that scale until a valid code is written to the device. High resolution and simple interface features make this Click board™ suitable for applications such as battery testers, communications equipment, factory automation and control, test and measurement, and more.

The output channel of the DAC80501, routed to the VOUT terminal, consists of a rail-to-rail ladder architecture with an output buffer amplifier that generates rail-to-rail voltages giving a maximum output range of 0V to VDD. The full-scale output range of the DAC output is determined by the reference voltage on the VREFIO pin, the reference divider setting, and the gain configuration for that channel set by the corresponding BUFF-GAIN bit. When the DAC80501 uses an internal reference, this voltage is also externally available at the VREF terminal and can sources up to 5mA. Besides, the user can bring the external reference voltage on this terminal in the case of the DAC80501 external reference configuration.

DAC 9 Click provides the possibility of using both I2C and SPI interfaces. The selection can be performed by positioning SMD jumpers labeled as COMM SEL to an appropriate position. Note that all jumpers must be placed to the same side, or else the Click board™ may become unresponsive. In SPI mode, the DAC80501 uses a 3-Wire SPI serial interface that operates at clock rates of up to 50MHz, while in I2C mode the DAC80501 can operate in Standard Mode (100 kbps), Fast Mode (400 kbps), and Fast-Plus Mode (1.0 Mbps).

This Click board™ is designed to be operated with both 3.3V and 5V logic voltage levels that can be selected via VCC SEL jumper. This allows for both 3.3V and 5V capable MCUs to use both the I2C and SPI communication lines properly. However, the Click board™ comes equipped with a library that contains easy to use functions and an example code that can be used as a reference for further development.

Specifications

Pinout diagram

This table shows how the pinout on DAC 9 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	NC
	NC	2	RST	INT	15	NC
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
	NC	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 9 Click electrical specifications

Software Support

We provide a library for the DAC 9 Click on our LibStock page, as well as a demo application (example), developed using MikroElektronika compilers. The demo can run on all the main MikroElektronika development boards.

Library Description

The library covers all the necessary functions to control the DAC 9 Click board™. This library holds functions that can be used to write data to the device in order to set up the device or set output voltage. Read function can be used with I2C communication exclusively.

Key functions:

• void dac9_soft_reset ( ); – The function is used to perform software reset.
• uint8_t dac9_set_gain ( uint16_t en_ref_div, uint16_t en_buff_gain ); – The function is used to set gain and internal voltage reference.
• uint8_t dac9_set_vout ( uint16_t vout_mv ); – The function is used set Vout ( mV ) by calculating input data and writing it to the DAC data register.

Examples description

The application is composed of three sections :

• System Initialization – Initializes I2C and SPI , sets CS pin as output and start to write log.
• Application Initialization – Initalizes SPI or I2C driver and applies default settings.
• Application Task – Demonstrates use of DAC 9 Click board™ by changeing output values every two seconds.

void application_task ( )
{  
    uint16_t n_cnt;
    
    for ( n_cnt = 0; n_cnt <= res; n_cnt += 500 )
    {
        WordToStr(n_cnt, log_txt );
        mikrobus_logWrite( "Output Voltage : ", _LOG_TEXT );
        Ltrim(log_txt);
        mikrobus_logWrite( log_txt, _LOG_TEXT );
        mikrobus_logWrite( "mV", _LOG_LINE );
        dac9_set_vout(  n_cnt );
        Delay_ms( 2000 );
    }
}

The full application code, and ready to use projects can be found on our LibStock page.

Other mikroE Libraries used in the example:

• I2C
• SPI
• UART

Additional notes and informations

Depending on the development board you are using, you may need USB UART click, USB UART 2 click or RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.

mikroSDK

This Click board™ is supported with mikroSDK – MikroElektronika Software Development Kit. To ensure proper operation of mikroSDK compliant Click board™ demo applications, mikroSDK should be downloaded from the LibStock and installed for the compiler you are using.

For more information about mikroSDK, visit the official page.