Q: TPS61175 external sync pull-down resistor

The external sync input doesn't  described as input current or impedance – input threshold levels only.  

It may suggest that external sync has the same nature as enable pin (has internal pull down within 500K). Is it true?

Could you describe in more details the input characteristics of the SYNC pin?

 

A:

Sync input is a MOSFET gate input without internal resistor termination. Therefore the terminations need to be done externally.  The SYNC pin may not be left floating.