Questions on TDA1543 & TDA1541

[mrstone]

Questions on TDA1543 & TDA1541

Hi Folks,

I'm new in this Forum and got some basic questions on Non-OS DAC....hope you guy can help to answer

Q1: Understand that a resistor will be connected between the DAC output and GND, so what are the best resistor valves for TDA1543 and TDA1541? and how to calculate them?

Q2: Just want to confirm the output of TDA1541 output is at 0Vdc. That means it can directly-coupled to another stage.

Thanks all!

Cheers
Mr. Stone

 

[dddac]

Re: Questions on TDA1543 & TDA1541

Hi Folks,

I'm new in this Forum and got some basic questions on Non-OS DAC....hope you guy can help to answer

Q1: Understand that a resistor will be connected between the DAC output and GND, so what are the best resistor valves for TDA1543 and TDA1541? and how to calculate them?

Q2: Just want to confirm the output of TDA1541 output is at 0Vdc. That means it can directly-coupled to another stage.

Thanks all!

Cheers
Mr. Stone

hi mr stone !
on the 1543 a lot of work has been done on this topic. just check www.dddac.de ....

the max value, due to internal limits for the 1541 is aprox 22 Ohm...

take care

doede

 

[alean]

Re: Questions on TDA1543 & TDA1541

Hi dddac,

the max value, due to internal limits for the 1541 is aprox 22 Ohm...

On what knowledge your statement about maximal limit TDA1541A of the loading resistor in 22 ohms is based?
Thank.

 

[dddac]

The 22 Ohm load is based on similar background of the load of the PCM63 (which is 100Ohm by the way).

The output is aprox 4mA for the 1541, so max output is aprox 90mV, as with the pcm63.

The way the currentsources are constructed, you get more distortion if the voltage acroos the output is rising. The design is actually meant to have 0Volt across the output through the virtual ground of an opamp.

Any way, also 100 Ohm will work (as 500 with the pcm63) but you have increased distortion and you can hear it.

For the pcm63 I did extended measurements my self. For the 1541 similar measuremenst have been done by others with the sam results and from that the 22 Ohm came out.

You can read on my WEB Site about this www.dddac.de
follow: description dddac200 (banner) then in the frame DAC Stage and in the text "technical bulletin with a digital scope and spectrum analyzer"

tc
doede

 

[alean]

Hi dddac,

Thank for the answer.

On an output of mine TDA1541A a constant voltage -107 mV. Scope of amplitude of a voltage on an output this value for maintenance of the minimal distortions means should not exceed. The resistor should be < 26 Ohm.

 

[Bernhard]

Hi dddac,

Thank for the answer.

On an output of mine TDA1541A a constant voltage -107 mV. Scope of amplitude of a voltage on an output this value for maintenance of the minimal distortions means should not exceed. The resistor should be < 26 Ohm.

minus 107mV ???

 

[alean]

Joke