Claus said:
I am looking for an op amp with similar specs to the CA3130 but usable
down to at least 4.5V.
It is being used as a voltage follower for a filtered PWM signal from
a PIC.
Can anyone please offer a suggestion? Or has anyone used the CA3130
successfully at 4.5V? It is rated at 5Vs min.
Claus
I am not sure what you mean by, "with similar specs to the CA3130".
I think the key words you need to look for are "rail to rail". This
means that either input or output or both operate all the way to the
supply rails. There are many low voltage opamps of this type
available, now.
There are also many low voltage "single supply" types that operate all
the way to the negative supply rail, but still don't work when signals
are within about a volt and a half from the positive supply rail.
I suspect that a rail to rail type would be best for tour application.
I don't know the frequencys involved, so here are a selection of low
to higher frequency types. These are duals, so they are not pin
compatible with the CA3130.
1.5MHz
http://cache.national.com/ds/LM/LM6132.pdf
10MHz
http://cache.national.com/ds/LM/LM6132.pdf
17MHz
http://cache.national.com/ds/LM/LM6142.pdf