Let's take the LT1763. The datasheet says that "The SHDN pin can be driven either by 5V logic or open-collector logic with a pull-up resistor." On the other hand the chart "SHDN Pin Threshold Off-to-On" says about 0.7V at 25*C temp suggesting 0.7V shall be enough to drive the SHDN pin high.
The question is whether 3.3V logic is enough to drive this line reliably? If not, which chart should I study?
I need the device to operate normally off and enable it from the microcontroller on demand. If the 3.3V cannot drive the SHDN pin correclty then I'll need to use an NPN and put the chip power supply between Vin and NPN's collector (for GND).