Lpc2000

Hi,

if you don't want to use a battery backup, you can leave Vbat open but
don't short it to V18. 
IMHO the PLCC44 does not connect the second V18, next to Vbat at all.
It can not be connected to Vbat internally because this would cause
V18 to go up to 3.6V with a new battery. 

Bob

--- In lpc2000@yahoogroups.com, "unity0724" <unity0724@...> wrote:
>
> Hi,
> On LPC2103, Can I short VBat to V18?
> The 2 pins are next to each other.
> => Simplify my PCB layout
> => Simplify my RTC backup circuit also, if V18 does not take too
>    much current when power down. Single micropower 1.8V LDO used.
> 
> Vbat requires 3.3V for normal Operation. 
> I do not fully understand the datasheet, does VBat work from 2.0V to
> 3.6V any time from chip operation to battery backup mode?
> On PLCC44, It seems like VBat and V18 are bonded to same pin (read
> from previous post) ??
> 
> I'm not using the full RTC section at the moment, may be will be 
> just using the RTC's second tick interrupt as 1mS interval timer 
> (Re-program prescaler to very fast "1 second").
> 
> Thanks
>