Lpc2000

I don't have an issue with the current drawn from Vdd in power down, I
can always cut the Vdd at the regulator.  But the Ibat is a lot higher
than a typical RTC chip at <1uA.  I don't know why it is >15uA and
they should have included the diodes to allow it to be powered from
Vdd when available.  I guess this RTC is better than none.  But it
won't fit my needs. 


--- In lpc2000@yahoogroups.com, Owen Mooney <ojm@s...> wrote:
> Thanks for the responses.
> 
> That's a disapointment. According to the datasheet the LPC2106 uses
about
> 10 uA on the 1.8V in power down - and a Max1616 regulator for 1.8 V
will use about 8 uA 
> so obviously the on chip 1.8V regulator has not been a good idea as
far as power
> is concerned. I think I expressed a concern about this concept earlier.
> 
> I'll probably stick with the PIC as I have all the development tools.
> 
> Owen
> 
> 
>  Date: Thu, 23 Dec 2004 05:14:04 -0000
>    From: "philips_apps" <philips_apps@y...>
> Subject: 
> Re: Any experience of the LPC2130 under very low power?
> 
> Hello Owen,
> 
> we did some bench measurements, these will probably show up as typical
> values in the data sheet for a later version:
> 
> If the device is in power down mode (the RAM content is kept and power
> is supplied to Vdd), we measured approx. 150 uAs. The value is related
> to the one voltage source 3.3V instead of having to provide 1.8V as
> well. We have to generate the 1.8V internally, even during power down
> because the RAM and the RTC run from 1.8V
> 
> The RTC itself can be buffered through a vbat pin. It uses approx.
> 15-20 uAs.  It is important to know that current from vbat is also
> drawn during normal operation.
> 
> So, can't provide you with the 50 uAs requested but the value is MUCH
> lower than the lpc2106 and you can log so much more data into the
> flash than with an AVR Mega or a MSP430 but at the cost of a larger
> battery.
> 
> Hope this helps, Robert