VDAC Voltage goes to maximum value while programming

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Anonymous
Not applicable

Hi,

   

While my PSoC5 is programmed with PSoC Creator the output of my VDAC component goes to the maximum value (in my case ~1V). Is there any chance to prevent this behaviour? Or is this a known problem?

   

PS: The initial value is set to 0.25mV (Hex: 1).

   

Kind regards,

   

Stefan

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ETRO_SSN583
Level 9
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1) Is that because VDAC pin is HiZ as default ? And not terminated in any

   

load that can absorb the leakage ?

   

 

   

2) What is the concern over this pin developing a voltage ?

   

 

   

Regard, Dana.

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Anonymous
Not applicable

2) The VDAC is connected to a transistor current source and i run into problems if i get the maximum current in my device while programming

   

1) well i understand, but is there an possibility to change this?

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ETRO_SSN583
Level 9
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While programming the PSOC GPIO, not having been configured during

   

boot, must be Hi Z digital. I have to check on this. What is the schematic

   

look like for the external current source, are you seeing enough leakage

   

from a Hi Z pin to create the problem ?

   

 

   

What is the range of current created by your external I source ? Maybe you

   

could use a GPIO to turn on its ground path once PSOC starts up ?

   

 

   

From ap note AN72382 -

   

 

   

www.cypress.com/

   


   

Startup and Low-Power Behavior

   


Out of the box, all GPIO pins start up in an Analog  HI-Z
state, where they  remain until reset is released.  The initial
operating  configuration of each pin is loaded  during  boot
and  takes  effect  at  that  time.  You  can  change  the  reset
behavior  of  GPIOs  using  the  PRTxRDM  fields  of  the
nonvolatile latch array, which are written when the PSoC
is programmed.

   

 

   

Regards, Dana.

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