Opto Couplers

[blu_line]

I like to isolate my bitstream converter (TDA1307) with opto couplers from the DAC (TDA1547).
Has any one ideas/links/circuits and suggested components ??

grtz

Simon

 

[BeanZ]

The HCPL-2232 and the rest of this HCPL series is an awesome high speed optocoupler for high speed digital applications. This is and Agilent (HP) part but I think that it may be syndicated by other manufacturers. You will probably need some driver circuit with most optocouplers including this series. This part is available through digikey and www.digikey.com.

BeanZ

 

[tiroth]

Jitter is sure to increase. I would use a series resistor instead...this presents some impedance to high speed switching currents without affecting the signal much.

What do you hope to obtain through the use of the optocoupler?

 

[BeanZ]

Jitter shouldn't increase much at all as long as you use proper grounding techniques and drive on both sides of the coupler. Also you may want to check out the ISO150 from Burr-Brown (TI). It is designed for this type of thing and they have similar applications. Optocoupling the signal ensures complete isolation of the analog and digital circuitry. Though that is not to say that noise can be coupled between them with poor design.

BeanZ

 

[blu_line]

thanks i will check them out.

I have spoken to the former designer of the DAC7 (TDA1547)
and he stated that opto couplers are one of the solutions to get
a good design with both the TDA1307 and TDA1547.

grtz

Simon

 

[alvaius]

Optocouplers tend to be quite jittery... just like a TOSLINK connection which is essentially an optocoupler. The ADuM1100 is based on different technology and tends to be much better.

However, limiting edge speed, and excellent layout are likely to accomplish what you are trying to do. That is my opinion and others will no doubt differ.