On Sat, 29 Oct 2011 01:23:26 +1300, you wrote:

>I was thinking you may be able to run it in shutdown with  a large
>enough cap to let it maintain voltage for "a while". I haven't tried
>to see how practical that would be. You need a /SHDN driver. Depending
>on how low a Vout you can tolerate a CMOS Schmitt inverter would be
>near ideal.
>
>>
>>>NB if you cam assert /SHDN then you get Idd of 0.1 - 1 uA.
>>
>> I see a bit of a gotcha there- the output voltage in "shutdown" won't
>> drop to ~zero, but rather input voltage less a diode drop. So, depending
>> on how the load behaves, the system load on the battery may not be ~100n=
A,
>> but could be considerably higher.
>>
>> The kind of boost converter without synchronous rectification doesn't ha=
ve
>> that feature, but efficiency will tend to be lower and they generally
>> require an external Schottky diode.

Probably not practical as I'll have a standby draw of around 10-20uA for an=
 RTC osc and Sharp memory
LCD - this is what the PFM mode is supposed to deal with, only kicking the =
coil when needed.=20

--=20
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