ICs from Futurlec

[Mike Warren]

I received 100 PT2258 ICs from Futurlec a couple of weeks ago and just
fitted the first one to my prototype PCB this afternoon.

It ran very hot. I assumed I had made an error with the board design,
but that was not the case. I fitted another IC with the same result. I
discovered that both ICs read about 3 ohms between the Vcc and analog
ground pins. I've now tested 22 of them and 10 of them read less than
60 ohms. The rest are over 30K. Of course, I don't trust any of them.

Looks to me like these have been subjected to a static discharge, and
if so, is a first to me in over 25 years. I have a good anti static
procedure, so am very confident it didn't happen here.

I had small concern when they arrived as the tubes had all been cut in
half and they were not in a metallic bag, but I've had CMOS sent this
way many times in the past (although, not from overseas) without any
problems.

Anyway, I've e-mailed Futurlec to see how they handle this, and wonder
if anyone else here has had a similar problem with Futurlec or another
supplier.


--
- Mike

 

[David L. Jones]

Mike Warren wrote:

I received 100 PT2258 ICs from Futurlec a couple of weeks ago and just
fitted the first one to my prototype PCB this afternoon.

It ran very hot. I assumed I had made an error with the board design,
but that was not the case. I fitted another IC with the same result. I
discovered that both ICs read about 3 ohms between the Vcc and analog
ground pins. I've now tested 22 of them and 10 of them read less than
60 ohms. The rest are over 30K. Of course, I don't trust any of them.

Looks to me like these have been subjected to a static discharge, and
if so, is a first to me in over 25 years. I have a good anti static
procedure, so am very confident it didn't happen here.

I had small concern when they arrived as the tubes had all been cut in
half and they were not in a metallic bag, but I've had CMOS sent this
way many times in the past (although, not from overseas) without any
problems.

Anyway, I've e-mailed Futurlec to see how they handle this, and wonder
if anyone else here has had a similar problem with Futurlec or another
supplier.

I would not rule out them being dodgy or rejected chips from the gray
market.
Actually I'd hazard a guess as this is where Futurlec get all their parts.
Just like buying at Tricky Dicks or Jaycar, it's a lucky DIP (pun intended).

Dave.

--
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[Mike Warren]

David L. Jones wrote:

Mike Warren wrote:
Anyway, I've e-mailed Futurlec to see how they handle this, and wonder
if anyone else here has had a similar problem with Futurlec or another
supplier.

I would not rule out them being dodgy or rejected chips from the gray
market. Actually I'd hazard a guess as this is where Futurlec get all
their parts.

Quite possibly. I've now tested all 100 chips and 74 of them read about
65K to 70K between Vcc and AGnd, so I'm guessing they may actually be okay.
I've grouped 3 that read about 35K with the bad ones.

None of the control inputs read very low on a couple of faulty chips I've
checked, so it may not be static. I'd expect one or more of the inputs to
read short to ground or Vcc, not that I really have any experience in
testing for static damage.

I'll fit one of the suspected good chips to my board and see if I can
get it to work. I haven't written the section of firmware that controls
it yet, so this will have to be next week.

Just like buying at Tricky Dicks or Jaycar, it's a lucky
DIP (pun intended).

I don't buy from DSE or Jaycar unless desperate, and even then only in
small quantities. I did get 6 from a shipment of 10 ULN2804s from WES a
few years ago that were faulty, but they replaced them without any fuss.


--
- Mike

 

[Ian Macmillan]

"Mike Warren" <miwa-not-this-bit@or-this-csas.net.au> wrote in message
news:xn0gigxlg4qeyx000@news.aioe.org...

I received 100 PT2258 ICs from Futurlec a couple of weeks ago and just
fitted the first one to my prototype PCB this afternoon.

It ran very hot. I assumed I had made an error with the board design,
but that was not the case. I fitted another IC with the same result. I
discovered that both ICs read about 3 ohms between the Vcc and analog
ground pins. I've now tested 22 of them and 10 of them read less than
60 ohms. The rest are over 30K. Of course, I don't trust any of them.

Looks to me like these have been subjected to a static discharge, and
if so, is a first to me in over 25 years. I have a good anti static
procedure, so am very confident it didn't happen here.

I had small concern when they arrived as the tubes had all been cut in
half and they were not in a metallic bag, but I've had CMOS sent this
way many times in the past (although, not from overseas) without any
problems.

Anyway, I've e-mailed Futurlec to see how they handle this, and wonder
if anyone else here has had a similar problem with Futurlec or another
supplier.


--
- Mike

I've bought quite a lot of ICs and FETS from Futurelec, always wary because
of the price, but so far I've had no problems, although I have probably not
squeezed the chips to their spec limits.

All the best
Ian Macmillan

 

[Mark Harriss]

Mike Warren wrote:

I received 100 PT2258 ICs from Futurlec a couple of weeks ago and just
fitted the first one to my prototype PCB this afternoon.

It ran very hot. I assumed I had made an error with the board design,
but that was not the case. I fitted another IC with the same result. I
discovered that both ICs read about 3 ohms between the Vcc and analog
ground pins. I've now tested 22 of them and 10 of them read less than
60 ohms. The rest are over 30K. Of course, I don't trust any of them.

Looks to me like these have been subjected to a static discharge, and
if so, is a first to me in over 25 years. I have a good anti static
procedure, so am very confident it didn't happen here.

I had small concern when they arrived as the tubes had all been cut in
half and they were not in a metallic bag, but I've had CMOS sent this
way many times in the past (although, not from overseas) without any
problems.

Anyway, I've e-mailed Futurlec to see how they handle this, and wonder
if anyone else here has had a similar problem with Futurlec or another
supplier.

I ordered 50 LM7555's from them and was supplied a non CMOS low power
version (HA17555). I pointed this out to them and they agreed it was
the case and a supply mistake on their part. I had to buy from Farnell
instead and three months later 50 LM7555's showed up in the mail from
Futurlec.