Substituting a HA-5221 opamp

[Philip Pemberton]

Hi,
I'm trying to get the components to build a current-voltage curve tracer
based on a Maxim appnote
(<http://www.maxim-ic.com/appnotes.cfm/appnote_number/253/ln/en&gt. Problem
is, the HA-5221 output opamp (or buffer - whatever it is) has been
discontinued by Intersil. I've just spent the past hour or so examining
various datasheets and out of the thirty or so I examined, only two actually
mentioned the output current capability of the opamp. Is there any way to
work this out from other values in the datasheet? I did notice that almost
all the comparator datasheets I examined mentioned the maximum output
current.
From my understanding of the article, it looks like I need a dual-supply
op-amp with a maximum output of +/-60mA or more.

Can anyone help me out a bit here?

Thanks.
--
Phil. | Acorn RiscPC600 Mk3, SA202, 64MB, 6GB,
philpem@despammed.com (valid address)| ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.dsl.pipex.com/ | 48xCD, ARCINv6c IDE, SCSI
No to DRM, software patents and the EUCD! <http://www.ukcdr.org/>
.... USAF : Usually Shooting At Friends

 

[Jamie]

interesting.
after looking at the details i would say if you could get your
hands on a old LM747 chip which is a higer voltage and sliglty more current
than the generic 741 chip i think you can get by..
actually i think a 741, TLO80 etc would handle 40 Ma.



Philip Pemberton wrote:

Hi,
I'm trying to get the components to build a current-voltage curve tracer
based on a Maxim appnote
(<http://www.maxim-ic.com/appnotes.cfm/appnote_number/253/ln/en&gt. Problem
is, the HA-5221 output opamp (or buffer - whatever it is) has been
discontinued by Intersil. I've just spent the past hour or so examining
various datasheets and out of the thirty or so I examined, only two actually
mentioned the output current capability of the opamp. Is there any way to
work this out from other values in the datasheet? I did notice that almost
all the comparator datasheets I examined mentioned the maximum output
current.
From my understanding of the article, it looks like I need a dual-supply
op-amp with a maximum output of +/-60mA or more.

Can anyone help me out a bit here?

Thanks.

 

[Philip Pemberton]

[Posted and mailed]

In message <102qa5qhqpi2079@corp.supernews.com>
Jamie <jamie_5_not_valid_after_5_Please@charter.net> wrote:

after looking at the details i would say if you could get your
hands on a old LM747 chip which is a higer voltage and sliglty more current
than the generic 741 chip i think you can get by..
LM747 is a dual 741. That and according to National Semiconductor it can only

do 25mA per channel - same goes for the 741. That and the 741 is about as
noisy an opamp as you can get :-/

actually i think a 741, TLO80 etc would handle 40 Ma.
TL081 -> 12mA per channel according to Natsemi's website.

The LM7171 looks suitable, and at least it's cheaper than Analog Devices's
offering. I'll get a 7171 from Farnell when the Maxim stuff arrives - then
I'll see just how well the curve tracer works

Thanks.
--
Phil. | Acorn RiscPC600 Mk3, SA202, 64MB, 6GB,
philpem@despammed.com (valid address)| ViewFinder, 10BaseT Ethernet, 2-slice,
http://www.philpem.dsl.pipex.com/ | 48xCD, ARCINv6c IDE, SCSI
No to DRM, software patents and the EUCD! <http://www.ukcdr.org/>
.... KLEPTOMANIA! Take something for it!

 

[Jamie]

hmm, thats strange.
my old Itel ref and i mean old does state that a 747 can handle 50 Ma.
but after looking at intel onlines docs, they are not the same as my
old printed book
i must take note of this because we recently have been replacing
747 chips more so that we should have, the original chips lasted for
years, then when they started go we now have problems running the
boards with out blowing over heating the chips now. we have been
installing cabinet fans to over come the problem, we never had to do
this for years
actually i do remember seeing some special additional prefix numbers
on the package that are not on the replacement chips we now use from
intel.




Philip Pemberton wrote:

In message <102qa5qhqpi2079@corp.supernews.com
Jamie <jamie_5_not_valid_after_5_Please@charter.net> wrote:


after looking at the details i would say if you could get your
hands on a old LM747 chip which is a higer voltage and sliglty more current
than the generic 741 chip i think you can get by..

LM747 is a dual 741. That and according to National Semiconductor it can only
do 25mA per channel - same goes for the 741. That and the 741 is about as
noisy an opamp as you can get :-/


actually i think a 741, TLO80 etc would handle 40 Ma.

TL081 -> 12mA per channel according to Natsemi's website.
The LM7171 looks suitable, and at least it's cheaper than Analog Devices's
offering. I'll get a 7171 from Farnell when the Maxim stuff arrives - then
I'll see just how well the curve tracer works

Thanks.