1 Reply Latest reply on Oct 9, 2018 2:13 PM by KTrenholm_1955226

    Confused regarding how much current 5LP GPIO pins can drive

    user_378053218

      Hi all,

       

      I'm confused regarding how much current 5LP GPIO pins can drive; any help is appreciated.

       

      Here's where I get confused:

       

      • The CY8CKIT-059's "User LED BLUE" is a LTST-C170TBKT from Lite-On Inc. 

       

      • This LED has a DC Forward Current of 20 mA, according to its data sheet. 

       

      • On the CY8CKIT-059, this LED is driven by P2_1 (via a 820 ohm resister), according to the CY8CKIT-059's schematics.
      • AN72382, § 2.4 states "In general, [PSOC 5LP] GPIO pins can source 4 mA."

       

      • If the GPIO pins can only source 4 mA (unless ganged), then how can P2_1 drive enough current to light "User LED BLUE" if that LED has a DC Forward Current of 20 mA?

       

      What am I missing here?

       

      I'm sure it is something really obvious.

       

       

      Thanks in advance,

       

      -Chris