Hi
My first post in this part of the site.
I am just starting to use Spice to model analogue circuits for the audio out from DACs. Several DACs provide their output as a current swing. As an example, the classic TDA1541 sits at a -2mA current sink with no signal and then swings ±2ma for full level.
I know that a current source with both AC and DC characteristics is available in Spice but the actual behaviour of a 1541 o/p is going to be more complex than that e.g. a finite output impedance. I thought about modelling this as a resistor in parallel with the current source?
Also, what is connected to the other end of the current source? My two current thoughts are either ground or the -6V supply.
TIA
Michael
My first post in this part of the site.
I am just starting to use Spice to model analogue circuits for the audio out from DACs. Several DACs provide their output as a current swing. As an example, the classic TDA1541 sits at a -2mA current sink with no signal and then swings ±2ma for full level.
I know that a current source with both AC and DC characteristics is available in Spice but the actual behaviour of a 1541 o/p is going to be more complex than that e.g. a finite output impedance. I thought about modelling this as a resistor in parallel with the current source?
Also, what is connected to the other end of the current source? My two current thoughts are either ground or the -6V supply.
TIA
Michael
Or you can use a voltage source in series with a resistor - completely equivalent to a current source in parallel with a resistor. "Thevenin equivalent circuit".
Reference your source to ground for an easy life.
Reference your source to ground for an easy life.