Hello,
I'm currently working on the design for a temperature measurement board featuring the ADS1147 ADC and so I have been trying to make an effort to use good design techniques and keep the power and ground as clean as possible so that I can maximize the 16 bits of resolution the device is able to crank out.
With that in mind, I chose the LP5912 to regulate the incoming 5V down to the 3.3V to be used on the board. What I was curious about was the following: in the datasheet it states that the PG output can be sent to a downstream device to indicate the status of the power rail and in the design a 10k-100k pull-up resistor should be placed from the PG to the OUT pin. From my research thus far in keeping noise levels low, it is preached to make sure to keep the noisy digital environment from being introduced into the ground (and power) through loop currents and other means. So with that in mind, is there an accepted practice for connecting the PG signal over to the digital world because in my mind I would be injecting noise directly into the power rail (through the pull-up resistor) and degrading the noise margin given in the datasheet.
My second, much more mundane question, is if it's fine to simply connect the enable pin to the 5V input rail (I have no intention of using the enable to go into power down currently).
(As a side note, the board will be a 4 layer FR4 PCB with dedicated power and ground planes and will be part of a larger multi-card system.)
Any help is much appreciated!
Best,
~Alex
