DAC81404: BOM for the external circuit shown in the DATASHEET.

Hi Sudhir, 

Sanjay will review and provide a response soon. 

Best,

Katlynne 

Hi Sudhir,

There is reference design in the DAC81404EVM, please check the page-10 in the user's guide https://www.ti.com/lit/ug/slau912a/slau912a.pdf?ts=1745556202993&ref_url=https%253A%252F%252Fwww.google.com%252F.

I would suggest to have a look and see if this helps. 

On the 1A current amplifier design, you can use  a amplifier with high current output i.e. - OPA541, OPA521 or OPA561. You check this link - https://www.ti.com/amplifier-circuit/op-amps/power/products.html#451typ=1.2%3B10&23typ=2%3B600&.

Let me know for any further help.

Thanks,
Sanjay

Hi Sanjay,

Thank You for sharing the EVM Schematics. I simulated the current amplifier circuit on LTspice using available transistor models.
This is the schematics and waveform which I obtained

The voltage at output is in mV and the current which I get is around the desired value which I want. But the voltage I am getting at the output is in mV. Is it because I am using a low resistance load which is causing this problem? 

Further, when I run simulation for -ve voltages

I am getting the output in Amps.

But in the EVM it is mentioned that the output is for -100mA to 100mA

Am I missing something in the simulations or do I need to follow a different method for current amplification?

And for the 1A output amplification do I need to use the Op-Amp as a voltage follower circuit?

Thanks & Regards
Sudhir D

Hi Sudhir,

Couple of issues here. 

You are running a simulation in open loop case and with very low load resistance. If you look at the application digram, current amplifier stage is within closed loop. 

Here is what you should try out. 
1. Set the load resistance = Vset /0.1A
2. Try to emulate a close loop simulation as shown in the application diagram below.

Please send the simulation schematic file, I can help in the situation for you if needed.

Thanks,
Sanjay