Why use amplifier with adc?

Started by Anonymous in sci.electronics.basics4 years ago 5 replies

I don't know very well how adc works, so i have a question. Most adc have a Vref pin that defines Vin range of adc. Vin range of adc is then...

I don't know very well how adc works, so i have a question. Most adc have a Vref pin that defines Vin range of adc. Vin range of adc is then divider for 2^n (n=resolution) to obtain LSB. If i resize Vref, new Vin range (smaller) is divided for 2^n, so LSB has smaller value.If i have a sensor, why i shoud use amplifier to drive Vin pin of adc?can i resize Vref as i like (or there is a limit)? ...


About ADC

Started by Anonymous in sci.electronics.basics9 years ago 3 replies
ADC

I have not understand some definition used with adc... 1)what is ENOB?A 12 bit adc with enob equal to 11 bit means that 11bit represent the real...

I have not understand some definition used with adc... 1)what is ENOB?A 12 bit adc with enob equal to 11 bit means that 11bit represent the real value and last 1 bit is error affected? 2)what is "noise free resolution"?What is it's difference with enob? Thanks in advance


ADC Selection

Started by Fibo in sci.electronics.basics3 years ago 6 replies
ADC

Hello, I have some questions on how to go about selecting an ADC for an application. I would like to take a voltage measurement across a...

Hello, I have some questions on how to go about selecting an ADC for an application. I would like to take a voltage measurement across a shunt. 1mOhm Shunt 500-1000 samples per second If possible I'd like to be able to see 0-200A with a resolution of 5mA? I think I'm just getting information overload from Google, but maybe a 24bit Sigma-Delta? I'm not sure... not sure how to start ...


Data Rates

Started by Anonymous in sci.electronics.basics2 years ago 5 replies
ADC

Hi, I am new to electronics. So, please be patient. I am trying to figure out the following problems for past 10 hours and can not get it...

Hi, I am new to electronics. So, please be patient. I am trying to figure out the following problems for past 10 hours and can not get it solved. I need to sample six sensors after every 20 minutes using a microcontroller. Four temperature sensors and two light sensors. Each sensor is connected to the six individual pin of the ADC. This ADC is integrated into the microcontroller chip. Th...


AMP, ADC, Transistor Questions!

Started by Anonymous in sci.electronics.basics1 year ago

Hello everyone. I am picking up on a project someone else worked and and I wanted to see if anyone had some ideas on a amplifier and ADC...

Hello everyone. I am picking up on a project someone else worked and and I wanted to see if anyone had some ideas on a amplifier and ADC connection that is being made in their schematic: 1.) See the schematic here: http://i1228.photobucket.com/albums/ee460/MrBlueCalifornia/qustion_zps3ck8j17m.jpg 2.) I am using a differenctial amplifier to measure a signal (U4 and U5 of


Flash ADC question

Started by Daku in sci.electronics.basics6 years ago 5 replies
ADC

Could some electronics guru please help ? In a flash ADC, there is a resistor chain, whose voltages at each node are the reference voltages for...

Could some electronics guru please help ? In a flash ADC, there is a resistor chain, whose voltages at each node are the reference voltages for the quantization levels. So, let us suppose that I want to digitize a sine wave, with +ve and -ve lobes - in this case how is the polarity of the reference voltages going to change, with each zero crossing ? In commercial designs, is there a togg...


Digital Electric Fence Tester?

Started by torg...@torgil.com in sci.electronics.basics8 years ago 3 replies

Hi! I've got an electric fence with 1Hz high-voltage pulses (2kV-10kV). I'd like to monitor the voltage from the fence using an ADC....

Hi! I've got an electric fence with 1Hz high-voltage pulses (2kV-10kV). I'd like to monitor the voltage from the fence using an ADC. Could anyone give me some ideas for a high-impedance circuit that could be connected to an ADC? Could I use a capacitor and a diode? Any ideas are welcome!


repeated data conversions

Started by Jon Slaughter in sci.electronics.basics10 years ago 5 replies
ADC

I was wondering just how bad data is corrupted through repeated conversions. I have this idea to test it and was wondering how hard it would be...

I was wondering just how bad data is corrupted through repeated conversions. I have this idea to test it and was wondering how hard it would be to set up. Essentially you have a ADC, DAC, buffer, and control system. you initially setup the buffer with the required digital data. Then the buffer sends the data into the DAC and the DAC feeds the ADC which then goes back into the buff...


External clock for Analog to Digital Converter

Started by Bilal Amin in sci.electronics.basics11 years ago 1 reply

Hi Everyone, I am working on Jitter in Analog to Digital Converters(ADCs). I am trying to setup an experiment to see the effects of jitter in...

Hi Everyone, I am working on Jitter in Analog to Digital Converters(ADCs). I am trying to setup an experiment to see the effects of jitter in real time ADCs. I have an ADC evalutaion board with external clock input for sampling (i.e Sampling clock). Now I want to produce a self created jittery signal to see the effects of jitter in ADC. Can anyone out there have any idea(s) how I can produc...


how I can connect 89c51serial port to telephone lineto send data?

Started by Anonymous in sci.electronics.basics10 years ago 6 replies

dear all, I try to send vedio from cctv via telephone line I connect the cctv camera output to ADC and the output of the ADC to Atmel...

dear all, I try to send vedio from cctv via telephone line I connect the cctv camera output to ADC and the output of the ADC to Atmel 89c51 micocontroller to send the data serial but I want to connect the output of the atmel89c51 to the telephone line please help? what the next step best regards yar


single ended or differential input

Started by Tareq Matar in sci.electronics.basics3 years ago 6 replies
ADC

what is the difference between these configurations on an ADC ?

what is the difference between these configurations on an ADC ?


multi input multi output analog to digital converter

Started by Tareq Matar in sci.electronics.basics3 years ago 9 replies
ADC

Is there a way to convert to different signals with one ADC instead of using two separate converters?

Is there a way to convert to different signals with one ADC instead of using two separate converters?


Impedance Calculation

Started by Rob in sci.electronics.basics10 years ago 3 replies
ADC

Hello, I have a quick question. I have an RC low pass filter and I need to calculate the impedance so I can match it to a SAR ADC. What...

Hello, I have a quick question. I have an RC low pass filter and I need to calculate the impedance so I can match it to a SAR ADC. What would the steps be to calcuate the impedance? Thanks, Rob


Importance to be in Full Scale for ADC

Started by Anonymous in sci.electronics.basics9 years ago 4 replies
ADC

Why is it important to be full scale when performing the analog-to- digital conversion?

Why is it important to be full scale when performing the analog-to- digital conversion?


Re: Does anyone know a way to take an audio signal and output it multiple times with different amplitude and phases tia sal2

Started by please_post_to_groups in sci.electronics.basics9 years ago 3 replies
ADC

Thanks for the response I know ADC is analog to digital converter but what is a LUT? Can anyone point to an example circuit with real...

Thanks for the response I know ADC is analog to digital converter but what is a LUT? Can anyone point to an example circuit with real components that may do this or an off the shelf item Tia sal2


What is an adc with pseudo-differential inputs?

Started by Anonymous in sci.electronics.basics10 years ago 2 replies
ADC

Hi. I've done some reading (eg Horowitz & Hill and other books), but I can't find an explanation to what pseudo-differential inputs is....

Hi. I've done some reading (eg Horowitz & Hill and other books), but I can't find an explanation to what pseudo-differential inputs is. Could someone explain or direct me to an application note? Thanks Juan Herrera


Magnitude Comparators

Started by Michael in sci.electronics.basics10 years ago 2 replies
ADC

Hi, I'm working on a school project where I need to compare 16bits (4 BCD values) from a CMOS logic system and need alternative ways of doing...

Hi, I'm working on a school project where I need to compare 16bits (4 BCD values) from a CMOS logic system and need alternative ways of doing it. So far I've got 4 cascaded 4063 bit comparators, ADC conversion but I'm struggling for a third. Can anyone suggest a method? I was thinking about using a CMOS compatible 74 series bit comparator but it's not really that different from the ...


Battery Level Monitor

Started by Michael in sci.electronics.basics11 years ago 3 replies

Hi, I'd like to create a 12V battery monitor and interface it to a PICAXE-08M running at 3.3V. What would be the best way to do this? I...

Hi, I'd like to create a 12V battery monitor and interface it to a PICAXE-08M running at 3.3V. What would be the best way to do this? I was thinking about using a 3.3V reg for the picaxe and then use a voltage divider so the changes in voltage can be picked up using the onboard ADC. Would I be right in assuming the resistor values should be about 10Kohms and 2.96Kohms? Cheers, ...


Analog multiplexor help

Started by Jan Nielsen in sci.electronics.basics10 years ago 12 replies
ADC

I was recommended to use a analog multiplexor to expand the number of ADC ports on a picaxe "cpu" earlier. I have now tried to use them for a...

I was recommended to use a analog multiplexor to expand the number of ADC ports on a picaxe "cpu" earlier. I have now tried to use them for a few days and cant get it working, any help please :) When I connect everything theres light in 2 of the 8 LEDs I used for a test, even when all 3 pins are low, if I remove the signal wire the 2 LEDs still light. I connected the 8outputs to a...


ADC current requirement

Started by nogoodinel in sci.electronics.basics11 years ago 4 replies
ADC

Im still working on ATmega16 which has buil-in A/D -converter. It seems that the converter is a drain for 10mA current ( 0 - 5 V ). Devise that...

Im still working on ATmega16 which has buil-in A/D -converter. It seems that the converter is a drain for 10mA current ( 0 - 5 V ). Devise that feeds the analog voltage gives only 5mA ( 0 - 10 V ). So at the moment when I connect the lines, voltage drops heavily from about 4 V --> some mV. Is there a way to work it out? 10mA sound quite big to me. Is there a possibility that there are som