Skip, The LM324 has many good features for low level requirements. High offset voltage (2 typ, 7 max, always design to max) and cross over distortion has always been an problem with much of what I do. It having 4 in a package is a plus and it has its place.
I should not say it, but I would not use Hamtronics as a source for design although I've been amazed at some things they do, hi. I would not use 324 for audio, but there are other applications. 73, ron, n9ee/r >From: skipp025 <[EMAIL PROTECTED]> >Date: 2008/04/23 Wed AM 10:17:17 CDT >To: [email protected] >Subject: [Repeater-Builder] Re: Carrier Control Timer (use the COR-2 circuit) > >> The 555 is dedicated as a timing device. > >When you work with it for any amount of time you come to >realize the design and layout is very practical and the chip >is now considered an industry work-horse. But it can be >used in linear applications... so never say never. > >> The LM324 is a quad op-amp and one of the poor ones. About >> the only advantage is 4 in one package. > >When is good enough, good enough? > > Internally frequency compensated for unity gain > Large DC voltage gain 100 dB > Wide bandwidth (unity gain) 1 MHz (temperature compensated) > Wide power supply range: Single supply 3V to 32V or dual > supplies ±1.5V to ±16V > Very low supply current drain (700 µA)-essentially > independent of supply voltage > Low input biasing current 45 nA (temperature compensated) > Low input offset voltage 2 mV and offset current: 5 nA > Input common-mode voltage range includes ground > Differential input voltage range equal to the power > supply voltage > Large output voltage swing 0V to V+ - 1.5V > >Another well known industry work-horse chip. Sometimes you might >not want a high performance chip in the drivers seat. There are >many cases where higher spec parts can work "to well". > >> As for use as a timer the 324 needs lots of glue to make it >> work. Not saying don't use it, but for a timing device the >> 555 is made for this with lots of flexibility. > >Sure the 555 is an industry standard timer chip, but an op >amp section can easily be made into a timer function without >much work. The Hamtronics COR-3 circuit is a perfect example >of where one chip does both functions very well. > >> If you want a op-amp I prefer the LF353 for audio and the >> LM358 has the rail-to-rail service and is better than a 324. > >If one wants to get nit picky over chips... I've got page lists >of better audio chip data sheets. But the 324 is more than >good enough for many tasks. A big plus is the cost per package >makes it a great dollar value. > >I once had to rework a simple op-amp design using the LM-3900 >Norton chip because it was the only animal that didn't immediately >go crazy at the mega watt rf-environment location. Sometimes dumb, >stupid and lower performance chips are the more practical or >cost effective answer. However, cost per pacakge most often >seems to be the person in the drivers seat making really large >quantity chip purchases. > >cheers, >s. > > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
