Decoupling capacitors...

On Friday, December 11, 2020 at 6:21:22 PM UTC-8, John Larkin wrote:
What exactly do you mean by \"on-chip\" in this context?
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.
Click to expand...

You can see some caps as well as the crystal inside the LMK61E2:
http://www.ke5fx.com/LMK61E2_30kVp_20s.jpg

The package is about 1 cm wide. Probably my favorite shot to date with
this machine.

Other shots (that I think I posted before):

LTM8049 buck regulator module
http://www.ke5fx.com/LTM8049_MX20_58256.146068_35kVp_15s.png

LT8650 buck regulator IC:
http://www.ke5fx.com/LT8650S_MX20_58230.228355_37kVp_7s.png

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ.
Click to expand...

Kintex BGAs have the internal caps, but AFAIK the lower-end parts
(including Zynq?) do not. It\'d sure be nice if they did.

-- john, KE5FX
 
On Fri, 11 Dec 2020 19:27:01 -0800 (PST), \"John Miles, KE5FX\"
<jmiles@gmail.com> wrote:

On Friday, December 11, 2020 at 6:21:22 PM UTC-8, John Larkin wrote:
What exactly do you mean by \"on-chip\" in this context?
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

You can see some caps as well as the crystal inside the LMK61E2:
http://www.ke5fx.com/LMK61E2_30kVp_20s.jpg

The package is about 1 cm wide. Probably my favorite shot to date with
this machine.

Other shots (that I think I posted before):

LTM8049 buck regulator module
http://www.ke5fx.com/LTM8049_MX20_58256.146068_35kVp_15s.png

LT8650 buck regulator IC:
http://www.ke5fx.com/LT8650S_MX20_58230.228355_37kVp_7s.png

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ.

Kintex BGAs have the internal caps, but AFAIK the lower-end parts
(including Zynq?) do not. It\'d sure be nice if they did.

-- john, KE5FX
Click to expand...

I measured a ZYNQ 7020. It definitely has some sort of caps on the
core and the bank supply pins.





--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.
 
John Larkin <jlarkin@highland_atwork_technology.com> wrote:
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

Please try!
Click to expand...

Thanks
--
Uwe Bonnes bon@elektron.ikp.physik.tu-darmstadt.de

Institut fuer Kernphysik Schlossgartenstrasse 9 64289 Darmstadt
--------- Tel. 06151 1623569 ------- Fax. 06151 1623305 ---------
 
lørdag den 12. december 2020 kl. 05.06.56 UTC+1 skrev jla...@highlandsniptechnology.com:
On Fri, 11 Dec 2020 19:27:01 -0800 (PST), \"John Miles, KE5FX\"
jmi...@gmail.com> wrote:

On Friday, December 11, 2020 at 6:21:22 PM UTC-8, John Larkin wrote:
What exactly do you mean by \"on-chip\" in this context?
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

You can see some caps as well as the crystal inside the LMK61E2:
http://www.ke5fx.com/LMK61E2_30kVp_20s.jpg

The package is about 1 cm wide. Probably my favorite shot to date with
this machine.

Other shots (that I think I posted before):

LTM8049 buck regulator module
http://www.ke5fx.com/LTM8049_MX20_58256.146068_35kVp_15s.png

LT8650 buck regulator IC:
http://www.ke5fx.com/LT8650S_MX20_58230.228355_37kVp_7s.png

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ.

Kintex BGAs have the internal caps, but AFAIK the lower-end parts
(including Zynq?) do not. It\'d sure be nice if they did.

-- john, KE5FX
I measured a ZYNQ 7020. It definitely has some sort of caps on the
core and the bank supply pins.
Click to expand...

It might depend on the package/device , table 3.1 list the required caps

https://www.xilinx.com/support/documentation/user_guides/ug933-Zynq-7000-PCB.pdf
 
On Fri, 11 Dec 2020 18:21:10 -0800, John Larkin
<jlarkin@highland_atwork_technology.com> wrote:

On Sat, 12 Dec 2020 00:54:00 +0000, Cursitor Doom <cd@noreply.com
wrote:

On Thu, 10 Dec 2020 16:52:19 -0800, jlarkin@highlandsniptechnology.com
wrote:

I don\'t think I have ever used too few bypass caps. Always too many.

I know one guy who didn\'t use bypass caps on digital boards, and his
stuff worked.

So was he

a) stupid
b) a genius
c) just lucky

His stuff worked, and he knew what he was doing.
Click to expand...

b) then. :)

I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.
Click to expand...

Well it certainly beats what I\'ve always done with DIL packages: strap
an ugly looking, long-leaded ceramic over the top diagonally.

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ.
Click to expand...

Yes sir. One less thing to worry about can\'t be bad.
 
On Sat, 12 Dec 2020 06:54:14 -0800 (PST), Lasse Langwadt Christensen
<langwadt@fonz.dk> wrote:

lørdag den 12. december 2020 kl. 05.06.56 UTC+1 skrev jla...@highlandsniptechnology.com:
On Fri, 11 Dec 2020 19:27:01 -0800 (PST), \"John Miles, KE5FX\"
jmi...@gmail.com> wrote:

On Friday, December 11, 2020 at 6:21:22 PM UTC-8, John Larkin wrote:
What exactly do you mean by \"on-chip\" in this context?
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

You can see some caps as well as the crystal inside the LMK61E2:
http://www.ke5fx.com/LMK61E2_30kVp_20s.jpg

The package is about 1 cm wide. Probably my favorite shot to date with
this machine.

Other shots (that I think I posted before):

LTM8049 buck regulator module
http://www.ke5fx.com/LTM8049_MX20_58256.146068_35kVp_15s.png

LT8650 buck regulator IC:
http://www.ke5fx.com/LT8650S_MX20_58230.228355_37kVp_7s.png

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ.

Kintex BGAs have the internal caps, but AFAIK the lower-end parts
(including Zynq?) do not. It\'d sure be nice if they did.

-- john, KE5FX
I measured a ZYNQ 7020. It definitely has some sort of caps on the
core and the bank supply pins.

It might depend on the package/device , table 3.1 list the required caps

https://www.xilinx.com/support/documentation/user_guides/ug933-Zynq-7000-PCB.pdf
Click to expand...

Hilarious. A CLG484 \"requires\" about 56 caps, about a dozen of which
are 47 uF or more.

I use about 10x 1uF ceramics total on a Zynq 7020 with DRAM. That\'s
probably overkill.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.
 
On 12 Dec 2020 11:56:18 GMT, Uwe Bonnes
<bon@hertz.ikp.physik.tu-darmstadt.de> wrote:

John Larkin <jlarkin@highland_atwork_technology.com> wrote:

I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

Please try!

Thanks
Click to expand...

OK, I\'ll ask the boys to do that on Monday.



--

John Larkin Highland Technology, Inc

The best designs are necessarily accidental.
 
On Saturday, December 12, 2020 at 12:50:57 PM UTC-5, jla...@highlandsniptechnology.com wrote:
On Sat, 12 Dec 2020 06:54:14 -0800 (PST), Lasse Langwadt Christensen
lang...@fonz.dk> wrote:

lørdag den 12. december 2020 kl. 05.06.56 UTC+1 skrev jla...@highlandsniptechnology.com:
On Fri, 11 Dec 2020 19:27:01 -0800 (PST), \"John Miles, KE5FX\"
jmi...@gmail.com> wrote:

On Friday, December 11, 2020 at 6:21:22 PM UTC-8, John Larkin wrote:
What exactly do you mean by \"on-chip\" in this context?
I think the caps are monolithic on the chip, on the core and the bank
supplies. The Xilinx BGA package is pretty thin and has no obvious
bumps. I suppose a few tiny ceramics inside are possible. Our Xray
doesn\'t have much resolution, but I might try. It\'s mainly a
parts-on-reels counter.

You can see some caps as well as the crystal inside the LMK61E2:
http://www.ke5fx.com/LMK61E2_30kVp_20s.jpg

The package is about 1 cm wide. Probably my favorite shot to date with
this machine.

Other shots (that I think I posted before):

LTM8049 buck regulator module
http://www.ke5fx.com/LTM8049_MX20_58256.146068_35kVp_15s.png

LT8650 buck regulator IC:
http://www.ke5fx.com/LT8650S_MX20_58230.228355_37kVp_7s.png

Anyhow, knowing about the internal caps means I don\'t need many bypass
caps on the board, and none need to be especially close to the ZYNQ..

Kintex BGAs have the internal caps, but AFAIK the lower-end parts
(including Zynq?) do not. It\'d sure be nice if they did.

-- john, KE5FX
I measured a ZYNQ 7020. It definitely has some sort of caps on the
core and the bank supply pins.

It might depend on the package/device , table 3.1 list the required caps

https://www.xilinx.com/support/documentation/user_guides/ug933-Zynq-7000-PCB.pdf
Hilarious. A CLG484 \"requires\" about 56 caps, about a dozen of which
are 47 uF or more.

I use about 10x 1uF ceramics total on a Zynq 7020 with DRAM. That\'s
probably overkill.
Click to expand...

Lee Ritchey talked about this in his class. I don\'t recall which vendor told him they didn\'t guarantee the design would work if he didn\'t use the excessive number of caps recommended. His reply was, \"Do you guarantee the design will work if I do follow the recommendations?\"

In the case of Xilinx they don\'t know what your design is doing. They have to allow for every FF in the package changing state at the same time as well as every I/O changing in the same direction. What are the chances that will happen?

--

Rick C.

++ Get 1,000 miles of free Supercharging
++ Tesla referral code - https://ts.la/richard11209
 
On Saturday, December 12, 2020 at 9:58:42 AM UTC-8, jla...@highlandsniptechnology.com wrote:
Please try!

Thanks
OK, I\'ll ask the boys to do that on Monday.
Click to expand...

I happen to have some of the CLG484 Zynqs on the shelf:
http://www.ke5fx.com/XC7Z020_1CLG484C_1I_MX20_59195_970706_35kVp_15s.png

If there are any caps in there, I sure don\'t see \'em. :( They usually jump out of the image,
barium titanate being on the opaque side.

-- john, KE5FX
 
On Friday, December 11, 2020 at 8:06:56 PM UTC-8, jla...@highlandsniptechnology.com wrote:
I measured a ZYNQ 7020. It definitely has some sort of caps on the
core and the bank supply pins.
Click to expand...

The ones I have came from a lot of 20 that I got from a surplus dealer in China.
They look kosher enough, but I\'ve never actually tried them. If you get a chance
to X-ray yours, it\'ll be interesting to see if they match. It doesn\'t take much
resolution to spot capacitors, given that no other features besides the balls
themselves tend to be as opaque...

-- john, KE5FX
 
søndag den 13. december 2020 kl. 00.35.21 UTC+1 skrev John Miles, KE5FX:
On Saturday, December 12, 2020 at 9:58:42 AM UTC-8, jla...@highlandsniptechnology.com wrote:
Please try!

Thanks
OK, I\'ll ask the boys to do that on Monday.
I happen to have some of the CLG484 Zynqs on the shelf:
http://www.ke5fx.com/XC7Z020_1CLG484C_1I_MX20_59195_970706_35kVp_15s.png

If there are any caps in there, I sure don\'t see \'em. :( They usually jump out of the image,
barium titanate being on the opaque side.
Click to expand...

yeh I dound one on google, https://media.springernature.com/original/springer-static/image/chp%3A10.1007%2F978-3-030-42068-0_7/MediaObjects/489022_1_En_7_Fig9_HTML.png

I think what looks like caps are on the back of the board
 
You must log in or register to reply here.

Welcome to EDABoard.com

Sponsor

Back
Top