Dac7563 timeout to Init to midscale

Oscar Gomez Fuente

Expert 2066 points

Other Parts Discussed in Thread: DAC7563

Hi,

I've been measuring the time between the power is on and the time the dac7563 places its output to midscale. I attached an image from my oscilloscope:

According to the figure 36. (page 16 from the datasheet of dac7563) this time It'll have to be less:

Could anyone help me?

Thank you so much. Best regards.

over 10 years ago

0 Eugenio Mejia over 10 years ago

TI__Genius 10615 points

Hi Oscar,

We usually don't guarantee a specification on the power-on time. The figures in the datasheet should be used as a typical value only, not a max value.

I will ask around with the designers to see if we can give you a better estimate.

0 Oscar Gomez Fuente over 10 years ago in reply to Eugenio Mejia

Expert 2066 points

Thank you, I'll wait for any advice from your engineers.

0 Eugenio Mejia over 10 years ago in reply to Oscar Gomez Fuente

TI__Genius 10615 points

Hi Oscar,

Apologies for the delay in my response, I must have missed the notification.

I was able to to talk to the designers, and they told me that this is not something that we design for. The plots on the datasheet can only be taken as a typical behavior. This is the first time that I have encountered a customer that is concerned with this power on timing spec.

Can you share the reason for which you need this timing to be consistent?

0 Oscar Gomez Fuente over 10 years ago in reply to Eugenio Mejia

Expert 2066 points

Hi Eugenio,

My target is to achieve the midscale as fast as I could because the output of the dac is going to this op-amp: e2e.ti.com/.../dac7563_5F00_design_5F00_opamp_5F00_20150714.png

With midscale I am going to get 0V. This output is going to command the speed of a thruster (input called SP_speed), and I need when I'll init my system the output of the dac will be midscale and so the output of the op-amp will be 0V. Do know what I mean?

Thank you so much. Best regards.

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Dac7563 timeout to Init to midscale