Single OpAmp with Class AB output stage

Hi DaADev,

I think LTC6081/LTC6082 or LTC6078/LTC6079 may be very close to OPA202 that you asked about. But they are duals and quads (not single like OPA202).

All of these have the LTspice model readily available from within LTspice program.

Regards,

Hooman

Sorry, it's better to view these parts in Excel as attached.

XLSX

Regards,

Hooman

Dear Hooman,

the OpAmps you suggested don't have bipolar output stage.

What i asked for is one equipped with bipolar class AB output stage. Pls have a look at the OPA202/2202 Datasheet where a inner circuit is shown. Or have a look even at LM108 or 741 Opamps which also have bipolar class AB output stage.

I still hope ADI has such OpAmps. Input Bias Current is less important. Board Space is an important constraint.

Best Regards

Achim

Hi Achim:  most of the LTC opamps had simplified schematics in the data sheet.  Check out LT1351 family, or LT1012 (low Ibias) or LT1007 or LT1028.  Are those the kind of output stage you're looking for?

Hi,

If I understand correctly, you need low voltage rail-to-rail version. Rail-to-rail output opamps can't have class AB complementer emitter follower output stage such as used in OPA202 and other opamps you've mentioned (see www.analog.com/.../mt-035.pdf).
I think it can be better to consider the specifications required by the application rather than the architecture, so you can try to find the one you need using the parametric search (www.analog.com/.../operational-amplifiers.html). RR opamps with high open loop gain can have very low closed loop output impedance, and if you need high capacitive load drive capability, you can still use RR opamps if you employ some kind of compersation technique (www.analog.com/.../techniques-to-avoid-instability-capacitive-loading.html).
If you pick one, you can use LTSpice to check the performance and stability.

Hi ZoltanDTI,

thanks for your reply. Capacitive Load is no issue as it would imply when reading OPA202 datasheet. for me the output stage design is of most importance. So i have had a second look at the OpAmp table and could find OP249 which has an output stage i would like to prefer.
Unfortunately we have space constraints here so i would like to ask you: Has the OP97 / 297 an output stage looking like that of the OP249?
Or do you have you another recommendation for me?
We would like to operate the amplifier with +/-5V Supply, driving no capacitive load and with output currents <1mA. Ibias should be <100pA and Vos should be <0.5mV.

Looking forward to your reply. Thanks in advance.

Achim

I do not know more about the OP97/OP297 what can be found in the datasheet. ADI engineers (Hooman or GlenBrisebois ) may help you regarding this. But it is very probable, that these opamaps have such output stage what you need. Both opamp seems to be very good. The requirements you've mentioned will be met for sure.
I still don't really understand, why the architecture is so important for you. Looking at the requirements I can't see any reason. Don't you need rail-to-rail output/input?