DAC81408EVM: PWL waveform output from DAC

Koshi Ninomiya

Part Number: DAC81408EVM
Other Parts Discussed in Thread: USB2ANY, DAC71408, PSPICE-FOR-TI, DAC81408, DAC80508, OPA593, DAC82002

Dear Team,

My customer is considering to use the DAC71408 (14-bit), and has the DAC81408EVM and the USB2ANY now.
They want to ouput PWL (Piece-wise Linear) waveform from the DAC81408EVM.
For example, a PWL signal source of the PSPICE-for-TI.

Can the PWL data be input to the DACx Data Register for the PWL waveform output on the DAC81408EVM software?

I look forward to your reply.
Thank you.

Best Regards,

Koshi Ninomiya

over 2 years ago

0 Sanjay over 2 years ago

TI__Expert 5450 points

Hi Koshi,

Yes, it's possible to provide input codes to DACx registers corresponding to a PWM output.

Can you the please some more details about the PWM frequency, DACx output update rates and output voltage requirements?

Thanks,

Sanjay

0 Koshi Ninomiya over 2 years ago in reply to Sanjay

TI__Expert 5655 points

Hi Sanjay-san,

My costomer wants to ouput PWL (Piece-wise Linear) waveform from the DAC81408EVM as follows,

5V:0s=>5V:10us=>0V:12us=>0V:17us=>40V:19us=>40V:24us=>5V:26us=>5V:36us（Repeat）
0V to 40V

Best Regards,

Koshi Ninomiya

+1 Sanjay over 2 years ago in reply to Koshi Ninomiya

TI__Expert 5450 points

Hi Koshi-san,

This PWL waveform will not be possible with DAC81408 because of-

1. slew rate for DAC81408 is only 4 V/us

2. minimum wait for the sequential update for DACx voltage output is 2.4 us

I would recommend to suggest the customer DAC80508 or DAC82002 device and use high voltage gain stage with OPA593 (it has very high 45 V/us slew rate).

DAC80508 datasheet

DAC82002 datasheet

Let me know if you need any further assistant.

Regards,

Sanjay

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DAC81408EVM: PWL waveform output from DAC