Audio frequency square wave generator ?
Robert W Schlenz
>Subject: Audio frequency square wave generator ?
>From: bac...@vms.huji.ac.il
>Date: 9 Jan 96 18:22:30 GMT
>Excuse my ignorance (I'm in cardiology) but is there an audio
>frequency square wave generator (0.01 Hz to 9999 Hz) that comes
>as a chip and that costs under $100 ? We need it for a device we're
>working on.
>Thanks.
>Josh
>bac...@VMS.HUJI.AC.IL
------------------------------------------------------------------------------
Try the ICL8038CCPD made by Harris, distributed by Newark (among others).
Newark catalog price is $3.75 in single quantity. The 8038 is a venerable
frequency generator IC that has square, sine, and triangle wave shape outputs.
The spec sheet says it's good for 0.001 Hz to better than 300 KHz.
Good luck on your project,
Roger schlenz
plastic green
> Excuse my ignorance (I'm in cardiology) but is there an audio
> frequency square wave generator (0.01 Hz to 9999 Hz) that comes
> as a chip and that costs under $100 ? We need it for a device we're
> working on.
The simplest way is to use a 555 timer chip which can be purchased for
under a dollar. It requires only a few external components (two resistors
and a capicitor or two, plus the power supply and an output, that's all)
and it can generate a wide range of frequencies, well covering the audio
range. (oh yeah, the audio range is only 20Hz to 20000 Hz).
I can give details if you need.
Dan Green
gr...@interaccess.com
bac...@vms.huji.ac.il
frequency square wave generator (0.01 Hz to 9999 Hz) that comes
as a chip and that costs under $100 ? We need it for a device we're
working on.
Thanks.
Kevin McMurtrie
Buy a beginner's IC cookbook. The parts cost a few cents each if you find
a good supplier.
bac...@vms.huji.ac.il
> In article <1996Jan9.182230.1@hujicc> bac...@vms.huji.ac.il writes:
>>Subject: Audio frequency square wave generator ?
>>From: bac...@vms.huji.ac.il
>>Date: 9 Jan 96 18:22:30 GMT
>
>>frequency square wave generator (0.01 Hz to 9999 Hz) that comes
>>as a chip and that costs under $100 ? We need it for a device we're
>>working on.
>
>
>>Thanks.
>
>
>>Josh
>>bac...@VMS.HUJI.AC.IL
>
> Try the ICL8038CCPD made by Harris, distributed by Newark (among others).
> Newark catalog price is $3.75 in single quantity. The 8038 is a venerable
> frequency generator IC that has square, sine, and triangle wave shape outputs.
> The spec sheet says it's good for 0.001 Hz to better than 300 KHz.
>
> Good luck on your project,
>
> Roger schlenz
Thanks.
Since this is voltage controllable from 0.001 Hz to over 300,000 Hz won't
I need a variable sequencer (1 Hz to 10 Khz) or a sequencer (0-5 volts) with
stepping from 0.01 volts ? This is what I understand form what our dept.
technician tried to explain to me. How else would I be able to use voltage
to get the exact frequency I need from the audio frequency square wave
generator ??
>
>
>
>
>
John Lundgren
: Excuse my ignorance (I'm in cardiology) but is there an audio
: frequency square wave generator (0.01 Hz to 9999 Hz) that comes
: as a chip and that costs under $100 ? We need it for a device we're
: working on.
: Thanks.
: Josh
: bac...@VMS.HUJI.AC.IL
Any common VCO chip like the 8038 or 2206 could be used. Or you could
just make one from an opamp or 555 timer chip in the astable mode. But
the 555 can get close, but never reach, 50 percent duty cycle. If you
add a few components to a CMOS chip like a 4069 hex inverter or a 4011
connected as an inverter, you can make a sq wave gen with low power
drain.
--
#======P=G=P==k=e=y==a=v=a=i=l=a=b=l=e==u=p=o=n==r=e=q=u=e=s=t======#
| John Lundgren - Elec Tech - Info Tech Svcs. | jlundgre@delta1 |
| Rancho Santiago Community College District | .deltanet.com |
| 17th St at Bristol \ Santa Ana, CA 92706 | http://rsc.rancho|
| My opinions are my own, and not my employer's. | .cc.ca.us |
| I have gone out to look for myself.. If I should |
| return before I get back, hold me until I get here. |
| "You can flame your brains out -- it won't take long." |
#===T=u=z=l=a==C=o=m=p=a=n=y=.=.===t=h=r=e=e='=s==L=e==C=r=o=w=d=!==#
Michael A. Wyatt
>
>Excuse my ignorance (I'm in cardiology) but is there an audio
>frequency square wave generator (0.01 Hz to 9999 Hz) that comes
>as a chip and that costs under $100 ? We need it for a device we're
>working on.
>
>
>Thanks.
>
>
>Josh
>bac...@VMS.HUJI.AC.IL
>
>
>
>
>
A number of people posted info on the ICL8038 function generator
chip, so I won't discuss the 8038. The new wave (pun intended) in lab
type function generators involves using a DDS (Direct Digital
Synthesis) chip followed by a DAC (Digital to Analog Converter) chip
for sinewave reconstruction. The output of the DAC is usually followed
by a low pass filter to remove the DAC's artifacts. Squarewaves can be
generated by "zero crossing" the low pass filtered sinewave. This all
sounds complicated but can be implemented with just a few chips and a
few discrete components. The frequency resolution of most DDS's is
better than 1ppm, and some are on the order of 1 ppb (2^32), yes
billion. The frequency accuracy is limited by the crystal clock that
drives the DDS. All this doesn't cost an arm and leg either, probably
$20 to $30. Check with Qualcom, Standford Telecom and Analog Devices
for DDS chips and app notes.
Hope this helps,
Mike Wyatt
plastic green
1995, pages 33-36 and 147. There's a schematic for a function generator.
Its based on a 8038 and it allows you to exactly pinpoint a certain
frequency. Its also relatively simple.
Dan Green