Counterfeit switching regulator...

P

Phil Hobbs

Guest
So we had a bunch of small power supply boards fabbed and stuffed in
Shenzen. The CM (PCBway) said they had all the parts in stock.

When we got the boards, everything worked great till the negative
switcher was enabled, at which point it went berserk. I talked about
that in another thread a few weeks back. It was strange--we\'d used all
those parts before with no issues.

I had a chance to investigate a bit more closely, and found that what
was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz async buck,
was in fact switching at 1.32 MHz. AO makes a quicker version, the
AOZ1282CI-1, that runs at 1 MHz, but its specified max is 1.2, and this
one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus bolonus. (*)

I\'ll try putting in the real ones and see if that helps.

Cheers

Phil Hobbs

(*) Damon Runyon
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On Thu, 5 Nov 2020 17:08:29 -0500, Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

I had a chance to investigate a bit more closely, and found that what
was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz async buck,
was in fact switching at 1.32 MHz. AO makes a quicker version, the
AOZ1282CI-1, that runs at 1 MHz, but its specified max is 1.2, and this
one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus bolonus. (*)

I\'ll try putting in the real ones and see if that helps.
Click to expand...

The Chinese seem to specialise in fake regulators for some reason.
 
On 05/11/2020 22:08, Phil Hobbs wrote:
So we had a bunch of small power supply boards fabbed and stuffed in
Shenzen.  The CM (PCBway) said they had all the parts in stock.

When we got the boards, everything worked great till the negative
switcher was enabled, at which point it went berserk.  I talked about
that in another thread a few weeks back.  It was strange--we\'d used all
those parts before with no issues.

I had a chance to investigate a bit more closely, and found that what
was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz async buck,
was in fact switching at 1.32 MHz.  AO makes a quicker version, the
AOZ1282CI-1, that runs at 1 MHz, but its specified max is 1.2, and this
one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus bolonus. (*)

I\'ll try putting in the real ones and see if that helps.

Cheers

Phil Hobbs

(*) Damon Runyon
Generally clearly visible under X-ray
Click to expand...


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
On 11/5/20 5:22 PM, TTman wrote:
On 05/11/2020 22:08, Phil Hobbs wrote:
So we had a bunch of small power supply boards fabbed and stuffed in
Shenzen.  The CM (PCBway) said they had all the parts in stock.

When we got the boards, everything worked great till the negative
switcher was enabled, at which point it went berserk.  I talked about
that in another thread a few weeks back.  It was strange--we\'d used
all those parts before with no issues.

I had a chance to investigate a bit more closely, and found that what
was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz async buck,
was in fact switching at 1.32 MHz.  AO makes a quicker version, the
AOZ1282CI-1, that runs at 1 MHz, but its specified max is 1.2, and
this one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus bolonus.
(*)

I\'ll try putting in the real ones and see if that helps.

Cheers

Phil Hobbs

(*) Damon Runyon

Generally clearly visible under X-ray
Click to expand...

Drat. Where _is_ that x-ray microscope I bought at last January\'s
hamfest? Ought to be here under the box of dilithium crystals where I
left it....

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On 05/11/2020 23:40, Phil Hobbs wrote:
On 11/5/20 5:22 PM, TTman wrote:
On 05/11/2020 22:08, Phil Hobbs wrote:
So we had a bunch of small power supply boards fabbed and stuffed in
Shenzen.  The CM (PCBway) said they had all the parts in stock.

When we got the boards, everything worked great till the negative
switcher was enabled, at which point it went berserk.  I talked about
that in another thread a few weeks back.  It was strange--we\'d used
all those parts before with no issues.

I had a chance to investigate a bit more closely, and found that what
was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz async
buck, was in fact switching at 1.32 MHz.  AO makes a quicker version,
the AOZ1282CI-1, that runs at 1 MHz, but its specified max is 1.2,
and this one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus
bolonus. (*)

I\'ll try putting in the real ones and see if that helps.

Cheers

Phil Hobbs

(*) Damon Runyon

Generally clearly visible under X-ray

Drat.  Where _is_ that x-ray microscope I bought at last January\'s
hamfest?  Ought to be here under the box of dilithium crystals where I
left it....

Cheers

Phil Hobbs

You don\'t have an X-ray machine for BGA insprection ?
Click to expand...


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus
 
On 11/5/20 7:13 PM, TTman wrote:
On 05/11/2020 23:40, Phil Hobbs wrote:
On 11/5/20 5:22 PM, TTman wrote:
On 05/11/2020 22:08, Phil Hobbs wrote:
So we had a bunch of small power supply boards fabbed and stuffed in
Shenzen.  The CM (PCBway) said they had all the parts in stock.

When we got the boards, everything worked great till the negative
switcher was enabled, at which point it went berserk.  I talked
about that in another thread a few weeks back.  It was strange--we\'d
used all those parts before with no issues.

I had a chance to investigate a bit more closely, and found that
what was supposed to be an AOZ1282CI, a fixed-frequency 450 kHz
async buck, was in fact switching at 1.32 MHz.  AO makes a quicker
version, the AOZ1282CI-1, that runs at 1 MHz, but its specified max
is 1.2, and this one\'s running at 1.32.

Sooo, it looks like somebody over there slipped us the phonus
bolonus. (*)

I\'ll try putting in the real ones and see if that helps.

Cheers

Phil Hobbs

(*) Damon Runyon

Generally clearly visible under X-ray

Drat.  Where _is_ that x-ray microscope I bought at last January\'s
hamfest?  Ought to be here under the box of dilithium crystals where I
left it....

Cheers

Phil Hobbs

You don\'t have an X-ray machine for BGA insprection ?
Click to expand...

Three or four, IIRC. I just can\'t find them under all these random
starship parts. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
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