• Resolved

TS5A3159: What happens if pin 6 is left floating while powered on

Part Number: TS5A3159

I am using the TS5A3159 part with Vcc = 5.5V.  I had a situation where pin 6 (IN) was left floating while Vcc = 5.5V.  High current draw was observed.  Once pin 6 was connected to 5V the current draw was observed to be normal.  Will the parts function as normal after having pin 6 floating on a few brief occasions with the parts powered on?

  • John,

    We always recommend that digital input pins like pin6 be pulled up to Vcc or ground to avoid the floating situation that causes high current consumption.  This can be accomplished by a weak pull up or pull down resistor as seen in the application diagram.


    You can also view this application note implications of slow or floating CMOS.

    The brief high supply current will not damage the part if it is within the absolute maximum ratings for the IC.  I don't think the current you are seeing with the floating digital logic pin is anywhere close to 100mA but that will be the current limit for the Vcc pin.  

    Thank you,