Other Parts Discussed in Thread: LMV792
Hello,
I work on decoding ultrasonic receiver with this lmv792. Amp A for differential amplifier, and amp B for comparator.
I saw at the datasheet on page 14 (RRO and Ground Sensing) that this is not recommended to work with this amp as comparator, I want to know why?
My data input is -+0.2v on 0v dc. This is O.k to put at the input -0.2volt at the amp?
please help me!
thank you,
idan.
In general, comparators allow large differential input signals. For example, a comparator with a 5V supply normally allows for one input to be held at +5V and the other input to be held at ground. This is not possible with most op amps. The LMV792, for example limits the differential input to +/-0.3V. This limitation is from back to back diodes on the input. These diodes will turn on and limit the differential input signal (see Abs max table below). Even though your input range is less than the absolute maximum, I would not recommend using this amp as a comparator because on the input diode structure is not recommended. I recommend reviewing the precision labs video on Electrical overstress (EOS) below. This video explains in detail how the back to back diode structure works.
https://training.ti.com/ti-precision-labs-op-amps-electrical-overstress-eos-2?cu=14685
