Hello,
Can anything be said about the outputs' states of the LM139 when this device is supplied (Vcc to GND) from 0V to 2V? This situation occurs during powering the device on or off. I need to be sure about its outputs' states during that condition.
Regards
Victor Muzell Jardim
Hello Victor,
Simply, there is no way to reliably predict what the output state will be. Every device will be different. We cannot guarantee this behavior.
Between 0V and 2V, the internal bias currents are in flux. Some things will bias-up before others, creating random transitions on the output. It simply does not have control of it's "bodily functions" within this "grey" zone.
Ambient temperature and the ramp rate of the supply, as well as the applied voltages to the inputs at the time, will also affect the output behavior.
The only thing to do is "gate" the output by controlling the pullup-resistor voltage or place a parallel transistor/FET to pull-down the output during power-up.
Regards,
Paul Grohe
Integrated Signal Chain Applications, SVA