FPGA Central

This again is a question for Austin:

The recommended operating conditions for spartan-3 are VCCINT < 1.26V.
What will happen if I power it with 1.28V?

Antything more serious than a live expectancy reduced from 20 years to
15 years?

You know, there a only a few small 1.2V regulators on the market but
there a plenty of 1.25V versions around. But those have a tolerance of
a few percent...

Kolja Sulimma

According to the data sheet, the absolute maximum VCCINT is 1.32 volts. This
would be 4% high side tolerence for a 1.25 V regulator. I am not aware of
any derating Xilinx has for higher voltages with their Spartan 3 device. I
would conclude a 1.25 V regulator would be acceptable. If you were really
paranoid you could tweak down the regulator by adjusting the passives in the
circuit.

"Kolja Sulimma" <[email protected]> wrote in message
news:[email protected] m...
> This again is a question for Austin:
>
> The recommended operating conditions for spartan-3 are VCCINT < 1.26V.
> What will happen if I power it with 1.28V?
>
> Antything more serious than a live expectancy reduced from 20 years to
> 15 years?
>
> You know, there a only a few small 1.2V regulators on the market but
> there a plenty of 1.25V versions around. But those have a tolerance of
> a few percent...
>
> Kolja Sulimma

All,

The voltage drop to the part might be just about 50mV....

Seriously.

I would try it an see what voltage the part actually is at relative to
the regulator. You might be pleasantly surprised.

Remember the part is specified by Xilinx to operate at the abs max
voltage AND temperature for the rated lifetime.

We prefer you stay within the recommended values, however.

Austin

fabbl wrote:
> According to the data sheet, the absolute maximum VCCINT is 1.32 volts. This
> would be 4% high side tolerence for a 1.25 V regulator. I am not aware of
> any derating Xilinx has for higher voltages with their Spartan 3 device. I
> would conclude a 1.25 V regulator would be acceptable. If you were really
> paranoid you could tweak down the regulator by adjusting the passives in the
> circuit.
>
> "Kolja Sulimma" <[email protected]> wrote in message
> news:[email protected] m...
>
>>This again is a question for Austin:
>>
>>The recommended operating conditions for spartan-3 are VCCINT < 1.26V.
>>What will happen if I power it with 1.28V?
>>
>>Antything more serious than a live expectancy reduced from 20 years to
>>15 years?
>>
>>You know, there a only a few small 1.2V regulators on the market but
>>there a plenty of 1.25V versions around. But those have a tolerance of
>>a few percent...
>>
>>Kolja Sulimma
>
>
>

OK.
As I am probably inside the recommended spec and for granted in the the
abs max spec I stop worrying.

Thank you Austin,

Kolja Sulimma

Austin Lesea <[email protected]> wrote in message news:<[email protected]>...
> All,
>
> The voltage drop to the part might be just about 50mV....
>
> Seriously.
>
> I would try it an see what voltage the part actually is at relative to
> the regulator. You might be pleasantly surprised.
>
> Remember the part is specified by Xilinx to operate at the abs max
> voltage AND temperature for the rated lifetime.
>
> We prefer you stay within the recommended values, however.
>
> Austin
>
> fabbl wrote:
> > According to the data sheet, the absolute maximum VCCINT is 1.32 volts. This
> > would be 4% high side tolerence for a 1.25 V regulator. I am not aware of
> > any derating Xilinx has for higher voltages with their Spartan 3 device. I
> > would conclude a 1.25 V regulator would be acceptable. If you were really
> > paranoid you could tweak down the regulator by adjusting the passives in the
> > circuit.
> >
> > "Kolja Sulimma" <[email protected]> wrote in message
> > news:[email protected] m...
> >
> >>This again is a question for Austin:
> >>
> >>The recommended operating conditions for spartan-3 are VCCINT < 1.26V.
> >>What will happen if I power it with 1.28V?
> >>
> >>Antything more serious than a live expectancy reduced from 20 years to
> >>15 years?
> >>
> >>You know, there a only a few small 1.2V regulators on the market but
> >>there a plenty of 1.25V versions around. But those have a tolerance of
> >>a few percent...
> >>
> >>Kolja Sulimma
> >
> >
> >