Hey,

Cool on getting it going :)

If the LPC exposed it's 1.8 V supply then you could just use a 'LV163 at
1.8 V. (Had to say it.)

For the cost of ~milliamp currents you could make your own 1.8 V supply
with a resistive divider. An 'LV163 should draw sub-milliamp at 1.5 MHz.

Maybe you could capacitively couple into the '163 and use a
megaohm-range divider to DC bias the input at around 3.3/2 = 1.65 V?
I think this seems cleanest given the options.


(2011.04.13) and...@psas.pdx.edu:
> So we have some options here:
> 
> 1. Get the LPC to output a 12 MHz clock (Timer? PWM? SPI?) on some GPIO
> line and feed that into the 74LVC163A.
> 
> 2. Get the LPC to output a 1.5 MHz clock (Timer? PWM? SPI?), bypass the
> counter chip completely, and feed that into the SPS chips.
> 
> 3. Hack in some sort of high speed comparator that converts the 1.6 V
> sine wave into a 3.3 V square wave output and feed that into the counter.
> 
> I'm currently leaning towards (2), since that's a very easy fix compared
> to (3)... Dave, can you easily scare up a 1.5 MHz clock? That's Fosc/8,
> for the record.
> 
> Any other ideas would be appreciated!

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