Voltage dacs in parallel

[pistollero]

Hello i need some help.
If i put two voltage cirrus or akm dacs in parallel what happens to the output voltage.
I m using a transformer on output with one dac.
And what happens to output impedance of the dacs?
Can i connect the two to the same transformer?

Tks

 

[abraxalito]

Putting two voltage-out DACs in parallel in theory lets you get twice as much current out. The voltage won't change though - best to use sharing resistors as their output voltages won't be completely identical, there's a certain tolerance on the voltage accuracy.

 

[pistollero]

Putting two voltage-out DACs in parallel in theory lets you get twice as much current out. The voltage won't change though - best to use sharing resistors as their output voltages won't be completely identical, there's a certain tolerance on the voltage accuracy.

Tks for the help.
But for example with one dac i use 47k parallel on the secondary side of transformer.. with two dac the value should be different?

When you say sharing resistors is putting a resistor in series with each + and -
In this case 1 resistor for two + and two - ?

 

[abraxalito]

The 47k on the secondary is to provide damping against the transformer's leakage inductance? If so it should be an RC not just an R - the damping is only needed at higher frequencies. The resistor is for the transformer so no, no need to change it if the trafo is driven by two DACs.

Sharing resistors go in series with the DAC outputs - driving a transformer you don't want to raise the output impedance too much, I'd try putting 47R in series with each and then join the 'far' end of the two 47Rs together - that's the node connected to the primary of the trafo.

 

[pistollero]

The 47k on the secondary is to provide damping against the transformer's leakage inductance? If so it should be an RC not just an R - the damping is only needed at higher frequencies. The resistor is for the transformer so no, no need to change it if the trafo is driven by two DACs.

Sharing resistors go in series with the DAC outputs - driving a transformer you don't want to raise the output impedance too much, I'd try putting 47R in series with each and then join the 'far' end of the two 47Rs together - that's the node connected to the primary of the trafo.

thks Abraxalito.
is the draw correct??
this is an ideia when i have the 2 dacs i want to test it...

 

[abraxalito]

Yes, that's the right idea.