Questions tagged [dac]

A DAC is a Digital to Analog Converter.

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Sporadic Noise Generated from AD5791 DAC Driven by DE10-Nano

I'm working with a system that allows me to set voltage waveforms on a PC and output them on the AD5791 DAC (eval board), with the DE10-Nano SoC/FPGA acting as an intermediary between the two. The HDL ...
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Opamp current source - Impedance matching to a laser diode - MHz range current modulation

I want to modulate the current through a laser diode with the output of a (FPGA into R2R DAC)source. I am using an opamp to do voltage to current conversion as shown in the circuit diagram. The laser ...
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How do I get a linear analog output from 8 bits BCD number?

I have two BCD counters I want to get an analog output from, I tried connecting them to a R-2R resistor ladder and it worked, partially, I get +~20 mV on each 1's increase, but when 10's increase I ...
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Audio: Can I use a stereo-amplifier with a mono DAC?

Here a schematics of my project: There is only one speaker (the sound is mono) The DAC I will use is a mono DAC, its reference is ES8311 and its datasheet is here: URL. It has two ouputs: OUTP and ...
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Building a linear current regulator from a 12V 50A SMPS using a BJT array and a DAC

I have an application where I need a digitally controlled constant current power supply capable of currents up to 50A. I have made a digitally controlled constant current power supply in the past, but ...
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How does one convert DC to AC in context of playing audio?

I'm working on a little gadget. A simple two button mini game with a simple oled i2c display. I wanted to add sound and a bit of music. Nothing too fancy, mainly drums using white noise and two or ...
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Supply voltage for opamp in a current sink circuit

I want to use an opamp in a current sink configuration in order to control the emitter-base current of a PNP transistor via a digital-analog pin from a microcontroller. The circuit is as shown below. ...
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GPD2846A mp3 module with headphones?

The GDP2846A module has an in-built 2W amplifier which is fine for a small speaker but not for a pair of headphones as it is indeed way too much. I've thought of directly taking the DAC outputs (...
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How does this timing diagram work

I am trying to control this DAC using an ESP32 via SPI. In the datasheet, I found this timing diagram in order to send an 8-bit serial word. \ I have implemented this using the below code. However, ...
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How to modulate the amplitude of a square wave at high speed (MHz)?

I want to build a modulator for driving a laser. I want the laser to produce square pulses with varying amplitudes. Hence I built a 1 MHz square wave oscillator (relaxation oscillator with an opamp.) ...
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How to simulate this circuit for common mode voltage effect?

Regarding my previous question and this paper, I wanted to simulate the circuit below to see whether it is rejecting common mode voltage as claimed. The paper says that sharing DAC's Vref with non-...
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Mapping different resolution ADC to DAC

I have a 24-bit ADC that is controlled by an FPGA. I want to take the ADC input and output it from a 16-bit DAC that is also controlled by the FPGA. Do I simply ignore the 8 LSB bits of the data and ...
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Estimating the worse case settling time to 0.1% (DAC)

So here is the question: The circuit: And the solution: Why is the worst case scenario considered in the middle of the string? Why is the capacitance 2C in the only switch that is on?
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2-bit charge redistribution DAC output

So here is the circuit: And here is the output: I presume answer c) is the output when there's a transition from phase 1 to phase 2. What about the transition from phase 2 to phase 1? Vout will be ...
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Sanity check on this DAC reconstruction filter design

I've altered a reconstruction filter circuit to use the LTC728XT instead of the AD8608 op-amp used in the example circuit below. Is anyone able to see any issues with my attempt? This is being used as ...
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Audio noise on output of PCM1789

I am developing a Bluetooth adapter to be able to listen to music from my phone in my car. I am doing that with ESP32, from which the audio data is sent to PCM1789 which converts it to the analog ...
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Where do these parasitic capacitances appear?

So here: I assume each transistor has some sort of parasitic capacitance and that adds up into the non inverting terminal of the op amp? Why do those parasitic capacitances appear and how can i ...
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Trying do understand this DAC problem

So here is the question : Here is the solution: I dont understand the origin of the parasitic capacitances and their effect (marked with (1)). Some books mentioned that the delay through the switch ...
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How can I generate this waveform?

I am trying to generate this waveform: basically a ramped square wave with a maximum frequency of 1KHz. My first thought was to use the DAC pin of a microcontroller, but are there any ICs that can do ...
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Connect 3-wire SPI to ESP32

I have an "SPI" 4 channels with the below pinouts, datasheet is here: They say this is an SPI DAC, but from what I remember SPI is the following: CLK MOSI MISO CS However the above IC does ...
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A question about gain setting of a DAC versus its supply voltage

I want to power this DAC chip with 3.3V using its Vdd pin. If Im not wrong, specs says nothing about output voltage vs supply voltage Vdd and the following formula is given: The chip uses a fixed 2....
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How does exactly this DAC work?

So here it is: I don’t know how exactly this circuits works. I don’t understand how that feedback loop sets up an accurate know current source biasing, and what transistor is it trying to bias, Q4? ...
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PCM5242 DAC: DSP Program and DSP Frequency for high sampling rates

I want to use a PCM5242 DAC (datasheet) in a project The DAC has a built in DSP core that I don't want to use for anything custom. The DSP can be programmed with custom code, or predefined codes in ...
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Problem with finding DNL and INL of a DAC from its datasheet

Regarding my previous question I'm interested is the error between consecutive step sizes of this DAC. I need to know DNL and INL of this DAC. I searched for keywords for INL and DNL in the datasheet ...
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DAC can't drive MOSFET source below certain voltage

I'm using a DAC to control the voltage at the source pin of BS170 N-Channel MOSFET. The purpose is to control the current (and therefore brightness) of a LED while the MOSFET has the gate and drain ...
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DAC70508 connected to Arduino does not give any output

I am trying to use a DAC70508 with an Arduino Mega, but I do not get any output from the DAC. I connected the SPI communication pins and the power supply pins of the DAC to the Arduino (Vio and Vdd to ...
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Creating a low frequency triangle wave with PWM from an MCU

I am trying to generate a 30Hz triangle wave from a MSP430FR5994 MCU (specifically with the MSP430FR5994 Development Kit. The reason why I am trying to do this is for a Continuous Wave, Frequency ...
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Component in series with digital communication lines

What is the component highlighted in picture? Main IC in the picture is PCM510xA.
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What is the maximum safe SPI baud rate for this DAC?

I'm trying to communicate with this DAC as quick as possible with a microcontroller board, and need to figure out what baud rate would be its maximum limit. There's 50MHz mentioned but I'm not sure. ...
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Trying to understand Integral nonlinearity in DAC/ADC

So here's the definition of INL: it is mentioned (underlined in red) that one of the lines can be a line drawn between the end points of the transfer function but in (a) that line appears to pass in ...
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Adding adjustable voltage capability to the output of a voltage tracker

Using part: TLS115D0LDXUMA1 I need to drive a 120mA maximum load @10V. The circuit must have the ability to adjust the voltage from Vref to 10V, where Vref=0-6V. One goal is to bias Vref lightly: 100 ...
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A question about interpreting DNL

Imagine a 12-bit DAC with a range 0.2V to 3.4V and its DNL spec given as ±2 LSB. I want to increase this DAC in stair step fashion(as shown in below illustration) from 0.2V to around 3.2V with around ...
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Using a reference voltage in place of GND for ICs

Problem as follows: I have a reference voltage that must not be loaded and a separate load that must be driven at a minimum of the reference voltage, but must be adjustable from the reference point to ...
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Why do DAC circuits put the output through an opamp?

In almost all the DACs found online, there will always be an inverting opamp connect to the output of the bias weight or R-2R circuit. But in the embedded courses in edx, there was no opamp and it ...
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DAC accuracy and calibration for an STM32 board

I have this SM32F407 microcontroller board. I am step increasing its 12-bit DAC by 3 counts per step where its range is 0 to 4095 and amplifying the output with an opamp: But I wonder how accurate is ...
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DAC controlled LED brightness

I'm trying to control the brightness of 2 LED, with a 2-channel DAC. My problem, is that even when the DAC outputs 0V, the LED lights up on the selected channel. For 0V DAC output, I can measure 2.1 V ...
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Can I have a microcontroller with one I²S module as digital signal processor?

I was not very sure what title I should use, but the idea is: We have a Bluetooth module (BM64) and a DAC (PCM5122.) We want to put the microcontroller (STM32 Nucleo-F303K8) in between for digital ...
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Why there is one line of code for DAC buffer settings STM32?

I'm trying to enable or disable two DAC outputs of STM32F407 board. STM32CubeMX tools shows the following options: Above I choose both output buffers as Enable. And the auto generated code is as ...
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Measure output voltage of a voltage regulator

I've been designing a switching voltage regulator and I need to make fairly accurate measurements of the output voltage (including the transient states etc.). I try to present my design in the ...
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2 votes
2 answers
82 views

What is my DAC clocking frequency for this STM32 board?

I'm trying to figure out the exact clocking frequency of the DACs for this board. Here is the clock config: And the code section for the DAC initilaztion: ...
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DAC output of the microcontroller does not increase after a point

This uC board is supposed to have two 12-bit DACs. But when I sweep from 0 to 4095, the DAC output stops increasing after around 4032 and settles to around 2.8V. I power the board by its USB port. ...
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Generating 0-10v from 3.3v pin with OP amp problem

I'm using this design to generate a voltage 0-10v using the Esp32 DAC It was taken from here https://github.com/bdring/Grbl_Esp32/wiki/Spindle-Types and partially works. Test code I'm using: ...
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What is the easiest way to generate a clock signal?

I'm pretty much a beginner with electronics, and I am currently making an audio circuit, using the TI PCM1755 24-bit DAC. For my application, the IC needs a 49152 kHz clock to its SCK pin. Is there a ...
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DAC differential output signal problem?

I'm trying to use a MAX5183 DAC to generate an analog voltage from a digital input. I have got it working in as far as the outputs follow the shape of the input digital waveform (just a sawtooth input ...
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PWM output for DAC and using DAC as reference voltage

I would like to use a DAC as a programmable reference voltage for a window comparator. The input of the DAC would be the Arduino's PWM output. Can I connect the Arduino's PWM output directly to the ...
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1 answer
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How to choose DAC for ECG simulator [closed]

I'm trying to design and build ECG simulator device. It's supposed to output voltage in millivolts range (with microvolts precision) using a pre-configured signal (either pre-recorded heart plot or ...
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What does dual DAC mode mean for this microcontroller board?

I have a STM32 development board with this manual, and regarding its two DACs somewhere in stm32f4xx_hal_dac.c file, the following is written: ...
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Linearity Loss on Single Ended to Differential Circuit

I have a board that converts a single ended output of a DAC to a differential signal with options for the common mode voltage. The output of my 20-bit DAC goes on the VOUT_BUFFERED signal here. At ...
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RF electronics: transmission line transformer

I got in charge of a schematic and I am checking its design. There is a DAC EV12DS480A with differential RF output. I showed the method that is used to go from differential to the single-end: I never ...
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How to fix Texas Instruments DAC81408EVM Internal Oscillator error

So I'm working with Texas Instrument's DAC81408EVM (https://www.ti.com/tool/DAC81408EVM) as an external DAC for a project I'm working on. I'm posting here because TI's forum won't let me ask questions ...
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