SNOAA35D April 2023 – December 2023 LM2901 , LM2901B , LM2901B-Q1 , LM2903 , LM2903-Q1 , LM2903B , LM2903B-Q1 , LM339 , LM339-N , LM393 , LM393-N , LM393B , LM397 , TL331 , TL331-Q1 , TL331B
A nice feature of the LM339 family (and ONLY applies to the LM339 family devices listed in Table 1-2) is that only one input needs to be within the valid input voltage range for a valid output. The other input can be above the input voltage range or, even above VCC and the output will be in the expected state.
This occurs because as long as one of the inputs is still within the valid input voltage range, that input pairs tail current (I1 or I2) is still flowing, signaling the correct output polarity to the active loads Q5 and Q6.
While this is a nice feature, it does come at a cost. When operating outside the specified input voltage limits, performance deteriorates and will no longer meet the data sheet specifications. Critical specifications such as offset voltage, bias current and propagation delay will be adversely affected. TI still recommends to stay within the data sheet input voltage range specifications.