DAC 13 Click

How does it work?

DAC 13 Click is based on the AD3541R, a single channel, 16-bit, 16-MUPS voltage output DAC from Analog Devices, with programmable output ranges. It uses a current steering DAC architecture with a reference voltage of 2.5V (internal but also with the possibility of an external reference voltage supplied on the VREF header), where DAC current is converted to a voltage through an internal transimpedance amplifier (TIA). The AD3541R also features multiple error checkers in analog and digital domains to guarantee a safe operation in various applications such as data acquisition systems, process control equipment, and many more.

The AD3541R has five pre-configured output voltage ranges: 0V to 2.5V, 0V to 5V, 0V to 10V, −5V to +5V, and −2.5V to +7.5V. The selection of the output range requires a combination of register configurations and a given transimpedance gain (x1 or x2 Output Gain jumper position). These drift compensating feedback resistors, or transimpedance gain, for the internal TIA scales the output voltage. The supply for the TIA integrated into AD3542R must be adjusted depending on the selected output span. In addition to the internal TIA supply, the user is provided with the possibility of an external trans-impedance amplifier supply on the connector marked with VEXT. Selection can be performed by onboard SMD jumper labeled as Output Amp Voltage, placing it to an appropriate position marked as INT or EXT.

This Click board™ communicates with MCU through a versatile SPI interface capable of operating in classic and dual SPI modes with a single or double data rate. The AD3541R has two update modes offering maximum speed and maximum accuracy, synchronously or asynchronously. A synchronous update occurs when the change of the DAC output is triggered by an external LDC signal routed to the AN pin of the mikroBUS™ socket, which with its low state, causes the DAC register to update if the input register has new data; otherwise, the DAC automatically updates when new data is written to the input register (LDC high). An asynchronous update occurs when the change of the DAC output follows an operation on the register set.

The AD3541R also possesses an additional interrupt alert signal, routed on the INT pin of the mikroBUS™ socket labeled as ALT, indicating abnormal conditions both in the analog and digital domains, and general reset function routed on the RST pin of the mikroBUS™ socket. The ALT pin is also asserted after reset and in case of initialization failure.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. A proper logic voltage level conversion is performed by an appropriate voltage level translator, while an onboard LDO, the AP2112, ensures recommended supply voltage level to power the AD3541R. However, the 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

Pinout diagram

This table shows how the pinout on DAC 13 Click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns).

Notes	Pin					Pin	Notes
Data Update	LDC	1	AN	PWM	16	NC
Reset	RST	2	RST	INT	15	ALT	Alert
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

DAC 13 Click electrical specifications

Software Support

We provide a library for the DAC 13 Click as well as a demo application (example), developed using Mikroe compilers. The demo can run on all the main Mikroe development boards.

The package can be downloaded/installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Library Description

This library contains API for DAC 13 Click driver.

Key functions

• dac13_set_output_range This function sets the output voltage range and as well as the @b ctx->v_zero_scale and @b ctx->v_full_scale variables for the selected range.

• dac13_set_dac_value This function sets the raw DAC value.

• dac13_set_output_voltage This function sets the DAC output voltage.

Example Description

This example demonstrates the use of DAC 13 Click board™ by changing the outputs voltage level every 2 seconds.

void application_task ( void ) 
 { 
     float step = ( dac13.v_full_scale - dac13.v_zero_scale ) / ( NUMBER_OF_STEPS - 1 ); 
     float out_voltage = dac13.v_zero_scale; 
     for ( uint8_t cnt = 0; cnt < NUMBER_OF_STEPS; cnt++ ) 
     { 
         if ( DAC13_OK == dac13_set_output_voltage ( &dac13, out_voltage ) ) 
         { 
             log_printf ( &logger, " Output voltage : %.2f Vrnn", out_voltage ); 
             out_voltage += step; 
             Delay_ms ( 2000 ); 
         } 
     } 
 }

The full application code, and ready to use projects can be installed directly from NECTO Studio Package Manager(recommended), downloaded from our LibStock™ or found on Mikroe github account.

Other Mikroe Libraries used in the example:

• MikroSDK.Board
• MikroSDK.Log
• Click.DAC13

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. UART terminal is available in all MikroElektronika compilers.

mikroSDK

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

For more information about mikroSDK, visit the official page.