ADC - DAC delay

knight23 · Sep 13, 2006, 03:45 PM

hi, im new here. sorry if this has been answered, i tried searching but i couldnt find what i was looking for.

how much delay is there in the DAC and ADC process?

thanks!

knight23 · Sep 16, 2006, 01:51 AM

follow-up: is there a way to measure the delay? suggestions?

thanks

dsdsdk · Sep 16, 2006, 02:07 AM

no idea.. my guess would be around 1ms. Do you need it to be precise?

dsdsdk · Sep 16, 2006, 02:12 AM

Delay from digital input to
analog output is a function of sample rate

2.72 ms at 28 kHz
2.51 ms at 32 kHz
2.10 ms at 44.1 kHz
2.01 ms at 48 kHz
1.55 ms at 88.2 kHz
1.51 ms at 96 kHz
1.45 ms at 108 kHz

The delay can be calculated
using the following formula:
Delay = 1.01 ms + (48/Fs)
Where Fs = the sample rate in Hz.

knight23 · Sep 16, 2006, 05:06 AM

Quote:

Originally Posted by dsdsdk

Delay from digital input to
analog output is a function of sample rate

2.72 ms at 28 kHz
2.51 ms at 32 kHz
2.10 ms at 44.1 kHz
2.01 ms at 48 kHz
1.55 ms at 88.2 kHz
1.51 ms at 96 kHz
1.45 ms at 108 kHz

The delay can be calculated
using the following formula:
Delay = 1.01 ms + (48/Fs)
Where Fs = the sample rate in Hz.

thanks!

where did you get this?
im trying to determine the filter length to use.

knight23 · Feb 2, 2007, 03:34 PM

did some feedback testing (connecting the ouput(rear/front out) directly to the input(line in)) with by audigy sb0090 card using profx.

what i found out...

d/a-a/d delay using ac97: 40 samples
d/a-a/d delay using uda: 52 samples with a 180 deg. phase difference?!

dont know how much specifically the delay due to d/a or a/d but im sure that the uda a/d is 12 samples slower than ac97.

Maddogg6 · Feb 12, 2007, 09:38 PM

I would think the DACs manufacturers offer this (delay) info in the form of a timing chart or something on their data sheets. Did you look there??? They may call it 'latency' ?? I cant think of a more appropriate term they might use.

Sep 13, 2006, 03:45 PM	#1
knight23 DriverHeaven Newbie Join Date: Sep 2006 Location: cebu, philippines Posts: 9 Rep Power: 0	ADC - DAC delay hi, im new here. sorry if this has been answered, i tried searching but i couldnt find what i was looking for. how much delay is there in the DAC and ADC process? thanks!

Sep 16, 2006, 02:07 AM	#3
dsdsdk DriverHeaven Senior Member Join Date: Oct 2003 Location: Denmark, CPH. Posts: 586 Rep Power: 0 System Specs	no idea.. my guess would be around 1ms. Do you need it to be precise? __________________ No more Kitty!

Sep 16, 2006, 02:12 AM	#4
dsdsdk DriverHeaven Senior Member Join Date: Oct 2003 Location: Denmark, CPH. Posts: 586 Rep Power: 0 System Specs	Delay from digital input to analog output is a function of sample rate 2.72 ms at 28 kHz 2.51 ms at 32 kHz 2.10 ms at 44.1 kHz 2.01 ms at 48 kHz 1.55 ms at 88.2 kHz 1.51 ms at 96 kHz 1.45 ms at 108 kHz The delay can be calculated using the following formula: Delay = 1.01 ms + (48/Fs) Where Fs = the sample rate in Hz. __________________ No more Kitty!

Sep 16, 2006, 01:51 AM	Thread Starter #2
knight23 DriverHeaven Newbie Join Date: Sep 2006 Location: cebu, philippines Posts: 9 Rep Power: 0	follow-up: is there a way to measure the delay? suggestions? thanks

Feb 2, 2007, 03:34 PM	Thread Starter #6
knight23 DriverHeaven Newbie Join Date: Sep 2006 Location: cebu, philippines Posts: 9 Rep Power: 0	did some feedback testing (connecting the ouput(rear/front out) directly to the input(line in)) with by audigy sb0090 card using profx. what i found out... d/a-a/d delay using ac97: 40 samples d/a-a/d delay using uda: 52 samples with a 180 deg. phase difference?! dont know how much specifically the delay due to d/a or a/d but im sure that the uda a/d is 12 samples slower than ac97.

Feb 12, 2007, 09:38 PM	#7
Maddogg6 Tail Razer Join Date: Jun 2005 Location: Bernyurass, AZ - USA Posts: 4,027 Rep Power: 0	I would think the DACs manufacturers offer this (delay) info in the form of a timing chart or something on their data sheets. Did you look there??? They may call it 'latency' ?? I cant think of a more appropriate term they might use.