LPC1758 RTC errata + LPC1758 power consumption from IRC/RTCclock

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LPC1758 RTC errata + LPC1758 power consumption from IRC/RTCclock

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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by man55 on Mon Jan 20 02:50:50 MST 2014
Hello !

LPC175x errata, rev.8.3:
Problem: The RTC does not work reliably within the temperature specification.

There is some info at the different forums about internal LPC175x and LPC176x RTC failure at high temperatures or at battery-to-main power switching.
But all of them are about RTC with external crystal !
Does anybody use internal LPC RTC with external clock generator ? External active generator with internal thermo compensated crystal with TTL-output level.
Can I use RTC domain at LPC1758, or it's not a good idea?

PS
Added: power consumption ?

Next question is about power consumption from IRC (IRC 4MHz clocking, active mode, all peripherials off, PLL off)
and from RTC clock + PLL (RTC 32kHz clocking, PLL on, core frequency 1MHz, active mode, all peripherials off)

Minimal active power consumtion in datasheet is "7mA at 12MHz w/o PLL" and we can't find any specs in datasheet about core power consumption
from internal IRC generator or from КЕС+PLCC clockimg scheme.
Where can we get this info?
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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by probatista on Thu Mar 13 05:47:15 MST 2014
Is it possible to know the revision a device without reading the top marking?

Since this issue is said to affect only revisions "Rev A" and '-', I want to buy a newer revision. The Errata sheet explains how to read the revision from the top marking, but I'll buy it on the internet and therefore will not be able to read it.

Does the 551 on this manufacturer part number "LPC1756FBD80,551" says something about it? I'm interested in this one: http://br.mouser.com/ProductDetail/NXP/LPC1756FBD80551/?qs=%2fha2pyFaduifPp1Rdf3p9P0nsUa%252bPB82arX...
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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by man55 on Tue Jan 21 18:47:13 MST 2014
Thank for your answer !

What about power (updated 1st post) ?
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lpcware
NXP Employee
NXP Employee
Content originally posted in LPCWare by mc on Mon Jan 20 15:56:45 MST 2014
Hi man55,
Just for your information there have been no RTC errata for Rev A devices. See below errata.
http://www.nxp.com/documents/errata_sheet/ES_LPC175X.pdf
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