Power consumption

stefano239955_stm1_stmicro · ‎2006-10-03

Posted on October 03, 2006 at 15:50

Power consumption

stefano239955_stm1_stmicro · ‎2011-05-17

Posted on May 17, 2011 at 09:31

hi.

I need to define the power supply stage for my board.

I didn't find the current for the core 1.8V and for the I/O.

Could anyone let me know if exist a table of power consumption

for any internal device? This thing could be useful also for

design of low power application.

spurious · ‎2011-05-17

Posted on May 17, 2011 at 09:31

Isn't the consumption curve in the datasheet? Page 51 - AC characteristics.

Oh... curve is not full throtle one.

[ This message was edited by: ssds on 09-09-2006 10:11 ]

taylor2 · ‎2011-05-17

Posted on May 17, 2011 at 09:31

I am looking for the same data.

I do not see the requirements clearly specified in the v3 Data Sheet or the v1 Reference Manual. I have seen a few reference designs using the LD1117 for 800mA on 3V3 and 1V8, but I hope that 800mA is gross overkill. I would like to use a smaller, cheaper 150mA regulator on at least the 1V8 line. A little more data from the factory would be nice.

roger_lynx · ‎2011-05-17

Posted on May 17, 2011 at 09:32

iamltr wrote:

I do not see the requirements clearly specified

Hm, define ''clearly'', ssds earlier mentioned pg 51 (Table 9)

it says:

1. core and peripherals running = 2.3 mA/MHz

2. core stopped peripherals running = 1.7 mA/MHz

3. core and peripherals stopped = 0.75 mA/MHz

ALL are MAX (not typical) values.

It is quite clear that in case 1. the max current drawn by device

is 220.8 mA (at 96MHz).

Basic algebra, fourth grade?

[ This message was edited by: hARMless on 02-10-2006 23:32 ]

taylor2 · ‎2011-05-17

Posted on May 17, 2011 at 09:32

The v3 datasheet labels 3V3 and 1V8 as VDDQ and VDD respectively. The AC Electrical Charactersitics section you reference provides current for IDDrun. Does IDDrun apply exclusively to VDD (1V8) or does it also cover VDDQ (3V3). Perhaps I need a lesson in reading as well as arithmetic, because it is not clear to me. What I need is a clear specification of maximum respective current draws for the 1.8V and 3.3V lines.

[ This message was edited by: iamltr on 03-10-2006 16:10 ]

roger_lynx · ‎2011-05-17

Posted on May 17, 2011 at 09:32

Perhaps I need a lesson in reading as well as arithmetic,

because it is not clear to me.

What I need is a clear specification of maximum respective

current draws for the 1.8V and 3.3V lines.

Surely, you must be joking?!

You cannot see the worst case from the

info that is in Table 9?

I will do what MacGyver would be doing, I suppose:

C=core (1.8V), I/O= well...I/O (3.3V)

a. C + I/O = 220.8 mA

b. I/O = 163.2 mA

subtract a - b, therefore C = 57.6 mA

b. I/O = 163.2 mA

c. OFF = 72.0 mA

subtract b - c = 91.2 mA, therefore I/O = 91.2 mA

at 96 MHz.

If you want to get better results than what I have eluded to,

I suggest you better to talk to STMicro.

It could be said, that 800mA LM1117 might be more than

one needs to supply the current for STR9, at either potential.

Oui?

taylor2 · ‎2011-05-17

Posted on May 17, 2011 at 09:32

I see where you get your numbers, but I think that you are making some unsupported inferences from the data in table 9 to get there.