SmartMedia Card will crash my system ?

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory card
to my system, my system power will be shifted, the VCC will be shit down to
ground abruptly and then reutrn to VCC, the ground is doing the same thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

 

[Rheilly Phoull]

One day bokiteam@ms21.hinet.net got dressed and committed to text

Hi All,
I enconuter a big problem, when I insert a SmartMedia
memory card to my system, my system power will be shifted, the VCC
will be shit down to ground abruptly and then reutrn to VCC, the
ground is doing the same thing, from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it
will auto reset ( restart) when I insert SmartMedia card, but it will
not happen every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

Words fail me !!

--
Regards ..... Rheilly Phoull

 

[martin griffith]

On Fri, 24 Jun 2005 20:18:34 +0800, in sci.electronics.design
<bokiteam@ms21.hinet.net> wrote:

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory card
to my system, my system power will be shifted, the VCC will be shit down to
ground abruptly and then reutrn to VCC, the ground is doing the same thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

rebuild the power supply, or find out why the SM is drawing enough

current to put the PSU into shutdown.
What is the maximum current the supply can deliver?
What are the startup parameters for the SM card
Are the 3V3 componets 5V tolerant?


martin

 

[martin griffith]

On Fri, 24 Jun 2005 20:22:39 +0800, in sci.electronics.design "Rheilly
Phoull" <Rheilly@bigpong.com> wrote:

One day bokiteam@ms21.hinet.net got dressed and committed to text

Hi All,
I enconuter a big problem, when I insert a SmartMedia
memory card to my system, my system power will be shifted, the VCC
will be shit down to ground abruptly and then reutrn to VCC, the
ground is doing the same thing, from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it
will auto reset ( restart) when I insert SmartMedia card, but it will
not happen every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

Words fail me !!
it's a wikiBoki post(TM), they normally arrive on fridays

martin

 

[Boki]

I didn't go to make sure the 3V3 componets have 5V tolerant or not yet.
Due to I can see the supply voltage will become lower than 5V( maybe 2V,
3V..whatever), I think that is a big issue, because my main chip (CPU) is
woking on 5V supply voltage, the others DRAM/UART/xxxx/... I think it maybe
not so important at this time, how about DRAM? will DRAM cause system reset
?

why the SM is drawing enough current to put the PSU into shutdown.
current is a good point.

one possible thing, the system will not( or very few) be reset before I add
EMI circuit/beds..

Best regards,
Boki.

"martin griffith" <martingriffith@XXyahoo.co.uk>
???????:sv5ob1ph661i0v2sudm9et3lvq2imspev4@4ax.com...

On Fri, 24 Jun 2005 20:18:34 +0800, in sci.electronics.design
bokiteam@ms21.hinet.net> wrote:

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory
card
to my system, my system power will be shifted, the VCC will be shit down
to
ground abruptly and then reutrn to VCC, the ground is doing the same
thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not
happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

rebuild the power supply, or find out why the SM is drawing enough
current to put the PSU into shutdown.
What is the maximum current the supply can deliver?
What are the startup parameters for the SM card
Are the 3V3 componets 5V tolerant?


martin

 

[Boki]

Does it possible if I add circuit that enforece 3V3 stronger? I mean, make
my 3V3 will not be shifted any more.

I hope I can do it in a simply way.... it is going to mass
production@@@@@@~~~~~~



<bokiteam@ms21.hinet.net> źśźgŠóślĽóˇsťD:d9gtms$jhr$1@netnews.hinet.net...

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory
card to my system, my system power will be shifted, the VCC will be shit
down to ground abruptly and then reutrn to VCC, the ground is doing the
same thing, from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not
happen every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

 

[Boki]

How about "Word beats me" ?

Best regards,
Boki.

"Rheilly Phoull" <Rheilly@bigpong.com> źśźgŠóślĽóˇsťD:42bbfb11$0$18645$14726298@news.sunsite.dk...

One day bokiteam@ms21.hinet.net got dressed and committed to text

Hi All,
I enconuter a big problem, when I insert a SmartMedia
memory card to my system, my system power will be shifted, the VCC
will be shit down to ground abruptly and then reutrn to VCC, the
ground is doing the same thing, from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it
will auto reset ( restart) when I insert SmartMedia card, but it will
not happen every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

Words fail me !!

--
Regards ..... Rheilly Phoull

 

[Boki]

The maximum current can supply by adapter is about 1000mA, it is working on
about 500mA.

Best regards,
Boki.

"martin griffith" <martingriffith@XXyahoo.co.uk>
???????:sv5ob1ph661i0v2sudm9et3lvq2imspev4@4ax.com...

On Fri, 24 Jun 2005 20:18:34 +0800, in sci.electronics.design
bokiteam@ms21.hinet.net> wrote:

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory
card
to my system, my system power will be shifted, the VCC will be shit down
to
ground abruptly and then reutrn to VCC, the ground is doing the same
thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not
happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

rebuild the power supply, or find out why the SM is drawing enough
current to put the PSU into shutdown.
What is the maximum current the supply can deliver?
What are the startup parameters for the SM card
Are the 3V3 componets 5V tolerant?


martin

 

[Boki]

It seems to be a big problem! We have no negative power supply.

What I were amazed is my old version circuit( without EMI circuit ) also
encounter this problem, but it almost never reset...


Please review this picture:

http://photo.xuite.net/boki.team/57013/22.jpg#picture

green line is VCC, yellow line is GND, (2V/grid in scope)




<cs_posting@hotmail.com>
???????:1119621952.216492.45730@g47g2000cwa.googlegroups.com...

bokiteam@ms21.hinet.net wrote:
Hi All,
I enconuter a big problem, when I insert a SmartMedia memory
card
to my system, my system power will be shifted, the VCC will be shift down
to
ground abruptly and then reutrn to VCC, the ground is doing the same
thing,
from 0V to -5V.

What are these voltages measured relative too? Where is the ground
lead of your scope probe connected? If part of your ground net (with
the probe tip) is reading -5v relative to another part (with the ground
clip) you have a serious problem! Are there even any negative power
supplies in the system?

If it were only the VCC dropping, it would seem like an inrush current
issue. I'd try another smartmedia card if one were available. Also
would considering putting together something to power up the card with
no signals connected, with a small series resitor in the ground lead to
it, and measure the voltage across that resitor, hence the startup
current. You should expect some startup current, which would be
supplied by capacitors located close to the card socket, but it
shouldn't be huge.

But what you are seeing in the ground suggests something more
systematic is wrong with the circuit or your measurement setup.

 

[martin griffith]

On Fri, 24 Jun 2005 20:18:34 +0800, in sci.electronics.design
<bokiteam@ms21.hinet.net> wrote:

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory card
to my system, my system power will be shifted, the VCC will be shit down to
ground abruptly and then reutrn to VCC, the ground is doing the same thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

nice picture

http://photo.xuite.net/boki.team/57013/1.jpg#picture
where is it?



martin

 

[martin griffith]

On Sat, 25 Jun 2005 00:28:31 +0800, in sci.electronics.design "Boki"
<bokiteam@ms21.hinet.net> wrote:

It seems to be a big problem! We have no negative power supply.

What I were amazed is my old version circuit( without EMI circuit ) also
encounter this problem, but it almost never reset...


Please review this picture:

http://photo.xuite.net/boki.team/57013/22.jpg#picture

green line is VCC, yellow line is GND, (2V/grid in scope)


snip
I missed this at the first look at your post

You are measuring it _incorrectly_. As cs_posting suggested
Check your grounding carefully. There should be no V on the ground
connection.
Or
You have the scope probe ground on a point that IS NOT GROUND.


martin

 

[James Meyer]

On Fri, 24 Jun 2005 23:34:03 +0800, "Boki" <bokiteam@ms21.hinet.net> wroth:

Does it possible if I add circuit that enforece 3V3 stronger? I mean, make
my 3V3 will not be shifted any more.

I hope I can do it in a simply way.... it is going to mass
production@@@@@@~~~~~~

Words now fail ME!

Jim

 

[Boki]

I am very sorry about that.

I am using something like this(but not this one):
http://www.emcesd.com/gndlead.jpg

and I measure the ground relative to the embedded system's ground.

The crocodile(?) clip of picture is connecting to system's ground, and the
probe is connect to the ground of components. ( they should the same
right?@@)

I use one probe to measure the 3V3 and the other one to measure GND...


Best regards,
Boki.

<cs_posting@hotmail.com>
???????:1119633774.940066.298710@g49g2000cwa.googlegroups.com...

Boki wrote:
It seems to be a big problem! We have no negative power supply.

What I were amazed is my old version circuit( without EMI circuit ) also
encounter this problem, but it almost never reset...

Please review this picture:

http://photo.xuite.net/boki.team/57013/22.jpg#picture

green line is VCC, yellow line is GND, (2V/grid in scope)

Picture won't open for me.

But I ask again, what is the voltage of ground being measured relative
to?

Where is the ground lead of the scope probe connected to the circuit?

You are using a ground lead, right?

 

[Boki]

Hi Martin,

"no V", do you mean 0V?

Yes, the ground is 0V, I just take some offset..


BR,
Boki.

"martin griffith" <martingriffith@XXyahoo.co.uk>
???????:vgrob1tj63iq9t857365b1vrs73b8ad8ij@4ax.com...

On Sat, 25 Jun 2005 00:28:31 +0800, in sci.electronics.design "Boki"
bokiteam@ms21.hinet.net> wrote:

It seems to be a big problem! We have no negative power supply.

What I were amazed is my old version circuit( without EMI circuit ) also
encounter this problem, but it almost never reset...


Please review this picture:

http://photo.xuite.net/boki.team/57013/22.jpg#picture

green line is VCC, yellow line is GND, (2V/grid in scope)


snip
I missed this at the first look at your post
You are measuring it _incorrectly_. As cs_posting suggested
Check your grounding carefully. There should be no V on the ground
connection.
Or
You have the scope probe ground on a point that IS NOT GROUND.


martin

 

[Boki]

Taipei 101

BR,
Boki.

"martin griffith" <martingriffith@XXyahoo.co.uk>
???????:l1hob1lpjfdfgnjufllc2k3o5s03hgieg3@4ax.com...

On Fri, 24 Jun 2005 20:18:34 +0800, in sci.electronics.design
bokiteam@ms21.hinet.net> wrote:

Hi All,
I enconuter a big problem, when I insert a SmartMedia memory
card
to my system, my system power will be shifted, the VCC will be shit down
to
ground abruptly and then reutrn to VCC, the ground is doing the same
thing,
from 0V to -5V.

my system ( embedded system ) will crash after that, in my case, it will
auto reset ( restart) when I insert SmartMedia card, but it will not
happen
every time, but it happens.

I main chip is running 5V, other components is running at 3.3V.

Could you please give me any hints?

Thank you very much!

Best regards,
F.Y.

nice picture
http://photo.xuite.net/boki.team/57013/1.jpg#picture
where is it?



martin

 

[Pooh Bear]

Boki wrote:

it is going to mass production@@@@@@~~~~~~

In its current state I suspect it isn't actually !

I think you may have a basic problem understanding how power supplies need to
be capable of high peak currents when powering digital circuits.

How much 'decoupling' capacitance do you have on your pcb ? How is it
distributed ?

How many layers on the pcb btw ? Do you have any dedicated ground and power
planes. What's the system clock frequency ?

If you have mixed 3.3 and 5 volts logic you *have* to use parts that are 'mixed
voltage I/O tolerant' where appropriate..

Where the memory card plugs in, you do have a large decoupling capacitor across
the supply rails don't you ?


Graham

 

[Pooh Bear]

Boki wrote:

I distributed the decoupling capacitance in every chips' VCC and
GND..., is that correct?

You have 1 per IC ? That's good. Multilayer ceramic presumably ?

4 layer.

Yes, I have dedicated ground and power planes.

Good.

3.3 and 5 V I/O tolerant is good point, but... ... does it possible
no tolerant between 3.3V and 5V? I remember we have to apply more then
10V or 15V to make MOSFETs breakdown, isn't it?

It doesn't work like that Boki ! IC's have 'parasitic paths' that can cause
breakdown problems if any pin exceeds ( or falls below ) substrate
potential by about 0.5 V. It all depends on the precise situation. Indeed I
just expereinced such a problem myself - although in very different
circumstances and for a very unexpected and subtle reason. I had a chip
going 'bang' on power-down. Took me a while to realise why. It was indeed a
substrate reverse-bias problem caused by a parasitic current path through
another IC !

Where? close to CPU and DRAM.
Yes, a large decoupling capactitor across the supply rails, but I think
due to the complicated GND,

What's complicated about it. That sounds like bad news ! This may be a
clue. And you need a big cap right next to the memory card socket.

we still have to add some L to critical
components, right?

Very carefully and only ever in critical locations where you're *totally
sure* of why you're doing it. And not in the ground path ever in this kind
of application.

Graham

 

It was indeed a
substrate reverse-bias problem caused by a parasitic current path through
another IC !

Vbs ( body , source ) ++, Vth --
Vth --, Id ++

Very good point, I will remember that!

Thanks a lot, Graham!

Best regards,
Boki.


"Pooh Bear" <rabbitsfriendsandrelations@hotmail.com>
???????:42C4E825.C2D4D617@hotmail.com...

Boki wrote:

I distributed the decoupling capacitance in every chips' VCC and
GND..., is that correct?

You have 1 per IC ? That's good. Multilayer ceramic presumably ?

4 layer.

Yes, I have dedicated ground and power planes.

Good.

3.3 and 5 V I/O tolerant is good point, but... ... does it possible
no tolerant between 3.3V and 5V? I remember we have to apply more then
10V or 15V to make MOSFETs breakdown, isn't it?

It doesn't work like that Boki ! IC's have 'parasitic paths' that can
cause
breakdown problems if any pin exceeds ( or falls below ) substrate
potential by about 0.5 V. It all depends on the precise situation. Indeed
I
just expereinced such a problem myself - although in very different
circumstances and for a very unexpected and subtle reason. I had a chip
going 'bang' on power-down. Took me a while to realise why. It was indeed
a
substrate reverse-bias problem caused by a parasitic current path through
another IC !


Where? close to CPU and DRAM.
Yes, a large decoupling capactitor across the supply rails, but I think
due to the complicated GND,

What's complicated about it. That sounds like bad news ! This may be a
clue. And you need a big cap right next to the memory card socket.

we still have to add some L to critical
components, right?

Very carefully and only ever in critical locations where you're *totally
sure* of why you're doing it. And not in the ground path ever in this kind
of application.

Graham