LPC812 power supply requirements

[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

[lpcware]

bump

[lpcware]

Content originally posted in LPCWare by Wojtkingson on Tue May 24 05:07:35 MST 2016
Solved - Enabled RESET pin, added resistor divider and capacitor to RESET pin, so the LPC starts little bit later and everything works ok.

[lpcware]

Content originally posted in LPCWare by Wojtkingson on Tue May 24 01:32:28 MST 2016
I´ve tried to find this information in UM and Datasheet, but I didn´t find any demands on power supply rising edge.

[lpcware]

Content originally posted in LPCWare by vtw.433e on Tue May 24 01:11:26 MST 2016
Did you read the Data Sheet (not the UM...):

http://www.nxp.com/documents/data_sheet/LPC81XM.pdf

I'm no expert, but 3s for power on? That sounds like about 10-times too long.