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Nobody had problems with the LM1036 ?

I've put together a circuit identical to that in National's Data Sheet. I get a near to 48 MHz sine wave of about 200 mV out of both outputs. This is with no input signals. I get this result with several different chips. I tried on solderless breadboard and a perfboard. Upper side is a ground plane where all capacitors are tied as short as possible. I tried first with conventional components (wired) and then with SMT. I tried also with a ground plane on the upper side where all capacitors were tied as short as possible. But all that without any result...

Any ideas? Thanks!

P.S. sorry for my poor english ...

Reply to
Daniel23
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"Daniel23"

** Try fitting a 330 ohm resistor in series with each output.

The output stage my not be stable with the capacitance of your scope lead directly attached.

..... Phil

Reply to
Phil Allison

Phil Allison a écrit :

directly attached.

Thanks Phil,

I have problems to read the NG. I've read yor answer on the web but it does not appear when I look in the NG ...

I tried with up to 1k in series with the outputs. Only effect: the amplitude decreased due to low-pass built by the resistor and the input capacitance of the probe.

I tried with the inputs shorted to ground (instead of 10k). No result. I tried decoupling the "zener ref" with caps from 100nF to 10uF. No result. Tried to change the value and the technology (Solid Al or tantal) of the caps at pin 1,6, and I put a 100nF parallel to these caps. But without any improvement.

The only way to get rid over the oscillation was to put a 220pF on each output to gnd. This solution does not satisfy me too well as long I do not understand what happens exactly...

Now I've sent an email directly to National Semiconductors. I'll wait what is happening ...

Reply to
Daniel23

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