Caller ID Generator Circuit

Other Hardware General Electronics
1

I found this circuit

963×532 77.8 KB

at http://www.edn.com/design/communications-networking/4360344/Generate-CID-CIDCW-analog-signals

But the TLV2472 Op amp used is not a familar part to me, suggest alternatives?, will any single rail Op amp do?

Thanks.

2

will any single rail Op amp do?

I would say not. The amp is feeding into a 680R load and then into a transformer. That is a heavy load for a normal op-amp.

3

LM386 then?

4

No not at all use a couple of 10 uF caps both those op amps are low pass filters with a corner frequency of 2900 hz the gain is nominal 2 If I remember right, I usually hack some thing close and pound on it until it works the way I want it to. There is a caution that might well take the '386 off the table, If I remember right it won't swing rail to rail and I have a hunch the other one will so output P-P levels can't be as large as the others in the schematic unless you used a 9 Vsupply. Both devices are just power buffers with filters wrapped around them.

Bob

5

Agreed, you need a rail to rail op amp with the high drive capability. Down load the data sheet for the TLV2472 and see what you have to match.

6

Thanks for the replies, Digikey have them in stock, but it will have to wait as shipping is expensive for orders under £50.

Farnell and RS have no listing for this part.

7

There doesn't seem to be any special requirement for the opamp and the signal they are dealing with is fairly slow. So yes, a LM386 or the like will work.

The amp is feeding into a 680R load and then into a transformer.

The 680ohm resistor is nothing to work about for most opamps. On top of that, the transformer will present a pretty good ac load. I wouldn't worry about it at all.