DAC8568: DAC8568 Can't work

Chen Alex1

Expert 2065 points

Part Number: DAC8568
Other Parts Discussed in Thread: DAC80508

hi sir

I use the FPGA to control the DAC8568, the FPGA is 2.5v, and DAC8568 AVDD is 5v

i can't control the DAC, after change to ADI/AD5668, the work normal

I think maybe is the VIH/VIL issue?

please advise it, thanks

3 months ago

0 Paul_Frost 3 months ago

TI__Guru 52683 points

Hi Alex,

The VIH for the DAC8568 is 0.625×AVDD, which is 3.125V in your system. So I think you are correct that this could be a VIH issue. Can you reduce the AVDD voltage and test to confirm?

Thanks,
Paul

0 Chen Alex1 3 months ago in reply to Paul_Frost

Expert 2065 points

hi Paul

after change to the ADI/AD5668, no the same issue

did you have other parts same as AD5668?

Thanks

0 Katlynne Jones 3 months ago in reply to Chen Alex1

TI__Mastermind 25563 points

Hi Alex,

What are the other requirements for the device? Are you requiring a p2p replacement?

We don't have very many devices that have logic levels that are independent of the VDD supply, but maybe we can find one that fits. Otherwise you will need to adjust the logic level or lower VDD like Paul suggested.

Best,

Katlynne Jones

0 Chen Alex1 3 months ago in reply to Katlynne Jones

Expert 2065 points

HI Sir

could you provide a solution, witch independent of the VDD supply?

spec same as DAC8568

thanks

0 Paul_Frost 3 months ago in reply to Chen Alex1

TI__Guru 52683 points

Hi Alex,

You could consider the DAC80508, which has a dedicated VIO pin for controlling the IO voltage.

Thanks,

Paul

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DAC8568: DAC8568 Can't work