par otazek tykajici se desky s vetsim FPGA

[Pavel Brabenec]

Zdravim,

to schema samozrejme znam, stejne tak jako schema desky od memecu s XC3S400.
Ale v datasheetu je napsano : Because the three supply inputs must be valid to release
the POR reset and can be supplied in any order, there are no specific voltage sequencing requirements. However, applying the FPGA’s VCCAUX supply before the VCCINT supply uses the least ICCINT current.... If the VCCINT supply is applied before the VCCAUX supply, the FPGA may draw a surplus ICCINT current in addition to the ICCINT quiescent current levels specified in Table 33.
The momentary additional ICCINT surplus current might be a few hundred milliamperes under nominal conditions, significantly less than the instantaneous current consumed by the bypass capacitors at power-on.

V tabulce 33 je pro XC3S5000 ICCINTQ 1450mA

Zdroj mam koncipovan takto:
VCCO - DC/DC 5V/3V3/6A, 
VCCAUX - LDO z 3V3 na 2V5/1.5A
VCCINT - DC/DC 5V/1V2/6A
takze stabilizator pro VCCAUX zacne nabihat az po nabehu 1V2 (menic na 3V3 je stejny jak menic na 1V2)

Takze se nabizi otazka proc deska od memecu s xc3S1500, a dalsi dve desky s xc3s2000 a xc3s4000 sequencovani ma.

Diky

P.B.
______________________________________________________________
> Od: danhard@volny.cz
> Komu: "HW-news" <hw-list@list.hw.cz>
> Datum: 18.10.2006 08:34
> Předmět: Re: par otazek tykajici se desky s vetsim FPGA
>
>http://www.digilentinc.com/Data/Products/S3BOARD/S3BOARD-rm.pdf
>
>
>> Spartan 3E Starter Kit ma tohle:
>>
>> IC7 is a Texas Instruments TPS75003 triple-output regulator. The
>> regulator provides 1.2V
>> to the FPGA´s VCCINT supply input, 2.5V to the FPGA´s VCCAUX supply
>> input, and 3.3V
>> to other components on the board and to the FPGA´s VCCO supply inputs
on
>> I/O Banks 0,
>> 1, and 2.
>>
>> A texas o tom pise
>>
>> Integrated Triple Supply Power Management IC for Xilinx(R)
Spartan(TM)-3
>> FPGAs
>>
>> PK
>>
>>
>> Petr Tošovský napsal(a):
>> > Ja mam Spartan 3 Starter Kit a sequencer tam nevidim (mozna spatne
koukam).
>> >
>> > Tosa
>
>
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