lpcware

Pull-ups Enabled on RESET

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 15, 2016 by lpcware
Content originally posted in LPCWare by neilt6 on Wed Jun 12 10:15:54 MST 2013

Hey guys. I'm getting progressively more irritated with the fact that pullup resistors are enabled by default on this LPC11U35 I'm playing with. Here's my situation: I'm building a battery powered device that has several active-high outputs that I need to hold low until my software is up and running (LDO enable, charger enable, etc). This becomes an even bigger issue when I try to use the USB bootloader for firmware updates. In this case, there's no way to shut the system off, because the pullup keeps the regulator enabled! How do you guys overcome this issue? I can use a strong pulldown resistor on these outputs, but that directly affects battery life.

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