The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
From: Fred Bloggs
User-Agent: Mozilla/5.0 (Windows; U; Win 9x 4.90; en-US; rv:1.0.1) Gecko/20020823 Netscape/7.0
X-Accept-Language: en-us, en
Subject: Re: Design for long interval timer
References: <firstname.lastname@example.org> <email@example.com> <3DEE0CAB.firstname.lastname@example.org>
Date: Wed, 04 Dec 2002 16:29:08 GMT
NNTP-Posting-Date: Wed, 04 Dec 2002 08:29:08 PST
Organization: EarthLink Inc. -- http://www.EarthLink.net
Winfield Hill wrote:
> Fred Bloggs wrote...
>>Spehro Pefhany wrote:
>>>for a timer.. consider using the MC14541.
>>Hmmm...a few problems with one:
>>1) ON is dropping products left and right;
> The availability of '4541' timer chips is certainly as safe to rely
> on as any IC. It's a popular, venerable design, widely stocked at
> good prices, and manufactured by five companies: Philips, TI, ST,
> Fairchild, and ON Semi. I'd probably buy an ON Semi IC, because
> Motorola originated the design.
>>2) the "exploded logic diagram" is clearly in error regarding the
>>MODE control logic;
> Use another vendor's data sheet if that bothers you. TI's data
> sheet (acquired from Harris = Intersil) has a good description.
> Of course one should always use the data sheet's Truth Table or
> Function table if in any doubt.
Okay- thanks for the advice....
>>3) the AUTO RESET only works for Vdd above 8.5V;
> "The AUTO RESET consumes an appreciable amount of power and should
> not be used if low-power operation is desired." Careful designers
> would consider avoiding use of a 'black-box' reset circuit anyway.
The 8.5V lower limit excludes 5V and this is more often than not a
> The 4541 design has much to recommend it, hence its over 30 years
> of popularity. Most of us have used it successfully for a variety
> of tasks in some of our designs.
I keep hearing that but don't see it. Looks like something with a lot of
unnecessary inputs that largely go unused, at the expense of providing
only a single Q output.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup