Searching \ for '[EE]: Comparator Quiz' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: www.piclist.com/techref/index.htm?key=comparator+quiz
Search entire site for: 'Comparator Quiz'.

Exact match. Not showing close matches.
PICList Thread
'[EE]: Comparator Quiz'
2002\05\25@165513 by Tal Bejerano - AMC

flavicon
face
Hi

Can I replace 2 LM741 with 1 LM1458 ?
I found a circuit that use 2 741 and I want to replace it with 1 chip.

Regards

Tal Bejerano
AMC - ISRAEL

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email spam_OUTlistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2002\05\25@180015 by Mark J. Dulcey

flavicon
face
Tal Bejerano - AMC wrote:
> Hi
>
> Can I replace 2 LM741 with 1 LM1458 ?
> I found a circuit that use 2 741 and I want to replace it with 1 chip.

In most cases, yes. The two amps in the 1458 have essentially the same
specs as the one in the 741.

There are two possible exceptions. If the circuit uses the offset
adjustment on the 741s, you can't sub a 1458, because the 1458 doesn't
have one.

If the circuit is EXTREMELY sensitive to crosstalk between the two
amplifiers, it might not work well with a dual part; because the two
amps in a 1458 are on the same die, and get power from the same pin,
it's impossible to completely eliminate crosstalk between them. But you
should really be building something critical like that with better amps
than 741s anyway.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body


2002\05\25@181809 by Jinx

face picon face
> Can I replace 2 LM741 with 1 LM1458 ?
> I found a circuit that use 2 741 and I want to replace it with
>1 chip.

For general purpose, yes. Internally they are identical,
apart from the two offset null pins on the 741 and a
couple of diodes inside the 1458

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listservspamKILLspammitvma.mit.edu with SET PICList DIGEST in the body


2002\05\25@182755 by Tal Bejerano - AMC

flavicon
face
to be more specific : it's the ultrasonic receiver part. the original use 2
741's.


Regards

Tal Bejerano
AMC - ISRAEL


{Original Message removed}

2002\05\25@191610 by Jinx

face picon face
> to be more specific : it's the ultrasonic receiver part. the original
> use 2 741's.

40kHz ? You will be OK for gain / bandwidth with 1458 if the
original works with 741s. 741s are veteran op-amps with not
great specs compared to today's devices and any general
purpose op-amp / comparator you can pick off the shelf will
sub for a 741. I'm guessing one 741 is used as an amp and
the other as a comparator. You can check out the bandwidth
(gain vs frequecy) figures for common op-amps - you'll find
they equal or better the 741. A 1458 should equal it

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\05\27@133136 by Peter L. Peres

picon face
On Sun, 26 May 2002, Jinx wrote:

>> to be more specific : it's the ultrasonic receiver part. the original
>> use 2 741's.
>
>40kHz ? You will be OK for gain / bandwidth with 1458 if the
>original works with 741s. 741s are veteran op-amps with not
>great specs compared to today's devices and any general
>purpose op-amp / comparator you can pick off the shelf will
>sub for a 741. I'm guessing one 741 is used as an amp and
>the other as a comparator. You can check out the bandwidth
>(gain vs frequecy) figures for common op-amps - you'll find
>they equal or better the 741. A 1458 should equal it

The 741 could be used with phase lead feedback and it could outspeed a
358.

Peter

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...