Special Holding DAC

Started by Bobby Joe in sci.electronics.design6 years ago 11 replies
DAC

I need to use a uC to control about 100 voltage outputs up to around 5V. A DAC would work find for this but I do not need to change the outputs...

I need to use a uC to control about 100 voltage outputs up to around 5V. A DAC would work find for this but I do not need to change the outputs very fast. I just need to be able to control it with one comm. line and for it to be able to hold it's value until it is set again. Do they make these types of DAC's? I don't need 100 outputs per DAC but would like 8 to 16. The comm. rate could be q...


Optocoupler and probing

Started by john in sci.electronics.design9 years ago 8 replies

Hello, I am trying to interface my FPGA board to the DAC board. The DAC needs four lines from the FPGA to work properly . I optocially...

Hello, I am trying to interface my FPGA board to the DAC board. The DAC needs four lines from the FPGA to work properly . I optocially isolated the four lines using four HCPL 2400. I powered up the FPGA board and DAC board separately using two different DC Lead acid battery (+5volts) inorder to preserve isolation. Now, I probed the power pins of the DAC and the optocoupler with oscillos...


DAC software

Started by DL in sci.electronics.design9 years ago 18 replies
DAC

Hi, I would like to incorporate a DAC in a board design so as to provide some biases in the rest of the circuit and was wondering if...

Hi, I would like to incorporate a DAC in a board design so as to provide some biases in the rest of the circuit and was wondering if anyone knows if any company provides software that could program their DAC through the serial or parallel port. Unfortunately, there is not much time for designing and testing so I don't have time to write the program myself. There are no tight specifications...


DAC resolution vs. smoothing filter cutoff-freq

Started by vkj in sci.electronics.design6 years ago 8 replies
DAC

Usually the smoothing filter after the DAC is supposed to have a cut-off freq.

Usually the smoothing filter after the DAC is supposed to have a cut-off freq.


Choosing a DAC

Started by john in sci.electronics.design9 years ago 2 replies
DAC

Hello All, I have chosen analog devices AD5532HS for my project. The main reason that I chose this DAC was because of its 32 voltage output...

Hello All, I have chosen analog devices AD5532HS for my project. The main reason that I chose this DAC was because of its 32 voltage output channels. You can find the DAC at http://www.analog.com/static/imported-files/data_sheets/AD5532HS.pdf My post is long and I request you to be patience and helpful. I need your help to understand and finalize the following issues 1. The data sheet...


current output DAC's

Started by Jamie Morken in sci.electronics.design9 years ago 11 replies
DAC

Hi, I noticed some DAC's are current output instead of voltage output, what is the practical difference when using these in a circuit and in...

Hi, I noticed some DAC's are current output instead of voltage output, what is the practical difference when using these in a circuit and in what situations would it be better to use a current output DAC? cheers, Jamie


16Bits DAC Output Buffer

Started by Habib Bouaziz-Viallet in sci.electronics.design7 years ago 1 reply

Hello all, It has been definitively not trivail to choose the right op-amp for this purpose : I/U converter for 16-Bits DAC. have you ever...

Hello all, It has been definitively not trivail to choose the right op-amp for this purpose : I/U converter for 16-Bits DAC. have you ever have been faced same problem ? Habib


DAC and 4-20ma output

Started by sandeepa in sci.electronics.design9 years ago 4 replies
DAC

What is the resolution of the DAC generally used in temperature controllers for a 4-20ma output ? I have made a temperature controller using...

What is the resolution of the DAC generally used in temperature controllers for a 4-20ma output ? I have made a temperature controller using PIC16f877a taht gives gives either relay outputs or pulses.Now i want to give 4-20ma output as well.So i need a DAC to convert the o/p from the PIC. I was looking at AD420 which has a resolution of 16bits.However, in such apps where the proportional ban...


DAC with GPIO?

Started by Anonymous in sci.electronics.design8 years ago 2 replies

Just an idle thought. A serial I2C DAC with a 6 pin package needs gnd,vcc,sda,scl,out. If you can select the I2C address as a variant of a base...

Just an idle thought. A serial I2C DAC with a 6 pin package needs gnd,vcc,sda,scl,out. If you can select the I2C address as a variant of a base part number, that leaves one free pin... I'd like that pin to be a GPIO, or just a digital out. I'd like to control the ENA pin of an OCXO with the same I2C bus as the DAC. Is there such a beast, and if not, why not! Maybe a 6 or 8 pin uC programme...


Calculating BW for DAC based PGA??

Started by anotherstevest in sci.electronics.design7 years ago 5 replies
DAC

Greetings, Of late I have been investigating a circuit (on paper) that includes a programmable gain stage (with an MDAC in an op-amp feedback...

Greetings, Of late I have been investigating a circuit (on paper) that includes a programmable gain stage (with an MDAC in an op-amp feedback loop in the somewhat common manner, in this case it's an LTC8043 DAC and OPA4277 op-amp). I intuitive suspect that using the DAC in the feedback loop at high gain settings is going to reduce the BW more than what the gain-bandwidth product would sug...


shunt voltage references can sink or source just fine right?

Started by acan...@wwc.com in sci.electronics.design8 years ago 3 replies
DAC

i need a 5V reference that can sink or source current for a DAC. a simple shunt reference like the LM4040 can do both just fine right?...

i need a 5V reference that can sink or source current for a DAC. a simple shunt reference like the LM4040 can do both just fine right? my thinking: 1- when the DAC is SINKING current, that means that current is flowing through the shunt resistor and into the DAC reference input. as long as the current into the DAC does not drop the voltage across the shunt resistor below the voltage at whi...


delta sigma dac

Started by Anonymous in sci.electronics.design9 years ago 1 reply

Hi, I am trying to build a delta-sigma dac using the outputs of an fpga. I need about 30mhz bandwidth and 8-10 bits. I was going to...

Hi, I am trying to build a delta-sigma dac using the outputs of an fpga. I need about 30mhz bandwidth and 8-10 bits. I was going to use an 8-bit r-2r ladder, but the i/o requirements are huge since i need 16 channels. The maximum output rate of the fpga pins is about 300mhz which is far to slow to get 8-10 bits@30mhz. If i use a dac larger than 1-bit could this work. Eg a 4-bit r-2r u...


Problem with audio amplifier

Started by eryer in sci.electronics.design8 years ago 2 replies

Hi, I have a problem with this audio amplifier (i'm new in this field, so excuse me for my...

Hi, I have a problem with this audio amplifier (i'm new in this field, so excuse me for my questions): http://focus.ti.com/lit/ds/symlink/tpa2005d1.pdf I've used it as single ended amplifier. It is connected to a DAC: between DAC and IN- a CR high pass filter is present. DAC can generete signals from 0 to Vdd (the same Vdd of TPA2005); so a value between -Vdd/2 +Vdd/2 is present in IN-. Fro...


I2S Audio DAC : Master Clock relationship

Started by Mahen K in sci.electronics.design7 years ago 2 replies
DAC

I amd trying to interface I2S audio from MCU connected to the DAC. Is it OK if I just use the LRCLK, BCLK and SDATA from teh MCU and connect the...

I amd trying to interface I2S audio from MCU connected to the DAC. Is it OK if I just use the LRCLK, BCLK and SDATA from teh MCU and connect the clean external Master clock (128-512Fs)to the DAC ignoring the MCLK from the MCU. What does the following statement from PCM1798 datasheet mean? Is it necessary to supply th same master clock that was used by the source (MCU) to generate LRCLK and BC...


Cheap DAC for PC

Started by Neville Kingston in sci.electronics.design8 years ago 9 replies
DAC

I am generating arb waves in PC software and do not want to loose the subaudio content by outputting via the soundcard. Can anyone suggest an...

I am generating arb waves in PC software and do not want to loose the subaudio content by outputting via the soundcard. Can anyone suggest an inexpensive ready-made DAC that will handle audio down to DC? I only need a single channel, so a dedicated stereo box is unnecessary. Many thanks, Neville Kingston


Integrated DAC solution required

Started by TTman in sci.electronics.design8 years ago 2 replies
DAC

Anyone know of an integrated 8 bit DAC/filter/amp? 250mW ish for the amp would be fine. I'm looking to upgrade an existing design that uses a...

Anyone know of an integrated 8 bit DAC/filter/amp? 250mW ish for the amp would be fine. I'm looking to upgrade an existing design that uses a couple of max part+ TDA7052. TIA


Peak limited "white" noise generator

Started by N_Cook in sci.electronics.design8 years ago 1 reply
DAC

Before ditching an audio effects unit Boss DD6 ( main 100 pin BOSS chip failed) I wanted to see if the DAC was still working . I cut data-in...

Before ditching an audio effects unit Boss DD6 ( main 100 pin BOSS chip failed) I wanted to see if the DAC was still working . I cut data-in line, pin 4 of DAC AK4352VT from the main Boss chip and connected , via 1K, to pin 9 , data out of the ADC AK5353VT. Feeding sine in the datastream varies on frequency. No data into the DAC then nothing out. Connect datastream and there is 2V peak lim...


Audio Amplifier

Started by eryer in sci.electronics.design8 years ago 1 reply

Hi, I have a little question: in practically all circuits that i have seen, two voltages are present 1. 3.3V used for DAC 2. 5V used for audio...

Hi, I have a little question: in practically all circuits that i have seen, two voltages are present 1. 3.3V used for DAC 2. 5V used for audio amplifier (in Bridge-tied load configuration) Why?Is not possible to use the same voltage (3.3V) for DAC and amplifier? I don't think it is strictly related to speaker volume...or not? Thanks


DAC with variable sample rate

Started by Oliver Glassl in sci.electronics.design9 years ago 5 replies

Hello! Is it possible to control the sample rate of a DAC (no oversampling, of course) with an analog VCO, variable within a wide range (few...

Hello! Is it possible to control the sample rate of a DAC (no oversampling, of course) with an analog VCO, variable within a wide range (few Hz up to 10Mhz), also frequency-modulated? First without consideration how to feed it properly. Regards, Oliver


Deglitching a DAC

Started by Spehro Pefhany in sci.electronics.design5 years ago 93 replies
DAC

Any clever ideas on getting rid of glitches in a high precision DAC output? Update rate is a fixed rate, probably in the 10-100kHz range, and...

Any clever ideas on getting rid of glitches in a high precision DAC output? Update rate is a fixed rate, probably in the 10-100kHz range, and I'd like to keep the glitches (especially variation in glitches) to < < 25ppm, preferably < 5ppm. A S&H with a low charge injection switch?