Low cost quad amplifier

Vladimir,

Is 1k ohm load terminated at GND or some other voltage?
In other words does output current always flow out of the device?

Vladimir,

First, there is no such thing as low cost bipolar op amp and no bipolar output can swing within 10mV of either rail since typical VCE saturation voltage is around 300mV at 25 deg C; that is UNLESS you are willing to use a pull-down resistor with an external negative supply to sink the entire output stage quiescent current like in the circuit shown below.

If you absolutely need to swing within 10mV to negative rail you must use CMOS op amp like OPA4170.  If you insist on using bipolar op amp, please consider OPA1664.  You may get some free samples by clicking on links below:

http://www.ti.com/product/OPA4170/samplebuy

http://www.ti.com/product/OPA1664/samplebuy

Dear Mr.Michallick!

Dear Mr. Lis!

Thank you.

Yes, 1k load terminated to GND, current always flows out of amplifier.

Sincerely,

Vladimir Naumenkov

www.agat.by

Please, answer, can I use opa4170 together with LM2901, please see attach

TIA

Vladimir,

Going back to your original question. LM324A meets your requirements when output current flows to ground.
How fast does the comparator need to be?

Dear Mr. Michallick!

Thank you.

As I need temperature minus 40 C, then I can use LM2902 (instead of LM324A)?  Please, could you recommend bipolar op amplifier with the approximately the same parameters and one amplifier in the housing (and low cost)?  As regards comparator, LM2901 suits us for speed.

Sincerely,

Vladimir Naumenkov,

www.agat.by

Vladimir,

LM2902 gives -40C temperature, but there is no "A" version with lower VIO.
LM124A does give low temperature but it won't be low cost.