Fully Differential Headphone Amplifier

[jan.didden]

Maybe we should wait until he runs out of pills ;-)

Jan

 

[808eengr]

Maybe we should wait until he runs out of pills ;-)

Jan

I'll wait until you run out of insults. Just ignore this thread and go do whatever you were previously doing. Don't you have an magazine to write? That's cool you know, working at a magazine.

 

[808eengr]

Maybe we should wait until he runs out of pills ;-)

Jan

Maybe you should wait for the design in this thread to stop working

 

[808eengr]

I'm inclined to agree. The current "stream of consciousness" in this thread does not really convey useful or helpful information. 808eengr, you might consider drafting your posts in a more coherent fashion 🙂

Duly (Differentially) noted

 

[808eengr]

See "Relationship to Frequency series and Frequency transform"

Z-transform - Wikipedia

 

[808eengr]

See "Relationship to Frequency series and Frequency transform"

Z-transform - Wikipedia

then the frequency transform of the correponsive LPF (a box) varies accordingly

 

[U102324]

What exactly are you trying to convey in all these posts. Are we looking at op-amp theory?

 

[808eengr]

What exactly are you trying to convey in all these posts. Are we looking at op-amp theory?

it's a thread

 

[808eengr]

v.047

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[808eengr]

thd+n @4kHz 2VRMs differential 125R 32mw 3.2uV DC offset

 

[808eengr]

the harmonic profile is looking good

 

[808eengr]

v.047 with OPA1656 quad buffer


thd (thd+n) @4kHz 2VRMs differential 125R 32mw 3.14uV DC offset


<a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/"> <img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" /></a> <br /> This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>

 

[808eengr]

New layout allows multiple feedback filter for OPA1642 composite amplifier configurations


....and v.074 is a low power version and ready for sim

 

[808eengr]

Maybe we should wait until he runs out of pills ;-)

Jan

Who lets you say whatever you want?

I think your words are just that... words

Results Didder. Results

 

[808eengr]

v.074 later today

 

[808eengr]

v.074
v.074 with dual AD8597 and OPA1642 quad buffer


thd @4kHz 2VRMs differential 125R 32mw 3.14uV DC offset
Total Harmonic Distortion: 0.000073%


thd @64kHz 2VRMs differential 125R 32mw 3.14uV DC offset
Total Harmonic Distortion: 0.000161%

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[808eengr]

the system couldn't resolve at 1k


run at 4k and 64k

anyone is square law up for a diff eq to approximate 1k thd


(f^n)*(n^n)

[(f^2)*(2^2)=f1, f=1k, n=2;] //(2VRMS 😕)
[(f^2)*(2^2)=f4, f=4k, n=2;]
[(f^2)*(2^2)=f64, f=64k, n=2;]



my coding is in need of a c++ update for sure

 

[808eengr]

Vuelo Fully Differential Hybrid Amplifier

(transresistance amplifier)



v.074 low voltage with AD8597 voltage gain stage and quad || OPA1656 current gain stage


using:

AD8597ARZ-REEL7DKR-ND
296-OPA1656ID-ND

thd @1kHz 1VRMs differential 125R 32mw 3.14uV DC offset
Total Harmonic Distortion: 0.000036%

thd @1kHz 2VRMs differential 125R 32mw 3.14uV DC offset
Total Harmonic Distortion: 0.000073%


thd @1kHz 4VRMs differential 125R 32mw 10.34uV DC offset
Total Harmonic Distortion: 0.001675%


square wave response 100kHz 100mV Single Ended (Vin- to GND)

<a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/"> <img alt="Creative Commons License" style="border-width:0" src="https://i.creativecommons.org/l/by-nc-sa/4.0/88x31.png" /></a> <br /> This work is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/4.0/">Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License</a>

 

[808eengr]

Note the symmetry with a non-offset input

 

[808eengr]

Vuelo Fully Differential Hybrid Amplifier v.0741

Vuelo Fully Differential Hybrid Amplifier v.0741

(transresistance amplifier current gain stage complete)

v.0741 low voltage with AD8597 voltage gain stage and quad || OPA1656 current gain stage

changed AD824 to AD823 over V/us error correcting integrator, adjusted component values

added 47 milliohm R's

2nd Harmonic is now ~ 90deg neg phase

DC offset now .7uV


thd @1kHz 2VRMs differential 125R 32mw .7uV DC offset
Total Harmonic Distortion: 0.000073%

using:

AD8597ARZ-REEL7DKR-ND
296-OPA1656ID-ND
LLC450HB-0R047-ND


over 3 million frequency series points 🙄


Date: Mon Jul 13 08:27:26 2020
Total elapsed time: 1232.752 seconds.

tnom = 27
temp = 27
method = modified trap
totiter = 7349283
traniter = 7343403
tranpoints = 3671543
accept = 3671139
rejected = 404
matrix size = 689
fillins = 2711
solver = Normal
Matrix Compiler1: 350.52 KB object code size 748.1/42.0/[18.4]
Matrix Compiler2: 104.40 KB object code size 22.0/29.9/[12.1]