lpcware

LPC812 power supply requirements

Discussion created by lpcware Employee on Jun 15, 2016
Latest reply on Jun 18, 2016 by lpcware
Content originally posted in LPCWare by Wojtkingson on Tue May 24 00:59:03 MST 2016
Hi guys,

I would like to ask, if there are any specific power supply requirements for LPC812 (exactly time of rising edge from 0V to 3V). I know, that Vcc should be between 1,8V and 3,6V. I try slow start, so power up takes about 3sec - from 0V to 3V and my LPC has problem to start.
It looks like to me, that some clocks are powered up wrong.

My firmware blinks with LED + BOD reset 2,06V - 2,15V

Example
1) Slow start from 0V to 3V - 3sec - LPC not running
2) LPC turned off by switch for about 2 sec and powered up by switch - LPC still not running, I have to wait more than 3 secs and than LPC runs (It happens only when the LPC is powered up wrong)

When I try this with switch ("fast" start) everything works fine

My test power source is laboratory power supply - 50cm of wires AWG 20 - capacitor 4u7 - capacitor 100nF - LPC812 - resistor - LED

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