Hi Vic,

On Mon, May 09, 2005 at 07:26:07AM -0400, Vic Fraenckel wrote:
> Range g ?2.0
> Sensitivity 2 mV/g 660 @3.3V
> 0g Offset vs. Temp.mV ?100 Over temp range?C -40 to 85
> Sensitivity vs. Temp % ?2.0 typical (?3.0 max) Over temp range
> Span mV ?1320 @ 3.3 V
> Noise 35 (x and y) 65 (z) typical
> Bandwidth Hz (0 to 3000 max (x and y axis) or (0 to 1500 max (z axis)) -3dB
> 
> Output Resistance Ohms 32K typical
> Non-Linearity % of FS ?0.1 typical (?0.5 max)
> Ratiometric Error % ?1.0 typical (?1.5 max)
> Cross-axis Sensitivity % ?2.0 typical (?3.0 max)
> Power Supply V 2.5 to 5.5
> mA 1.5 typical (1.8 max) Current draw @ 3.3V
> ?A <10 Shutdown pin connected to GND
> ms 1.6 Power-up time @ 500 Hz 6
> 
> If I were to interface this directly to a PIC with a 10 bit ADC would this 
> be a
> reasonable solution? Would I get good conversion accuracy. Would I need to 
> make
> provisions to shift the span from +/- 1320 mV to 0 to 5 volts. If this is a
> better way, could you advise me as to how to do this.

You will need at least a buffer amp. The A/D source impedance needs to be
10k or less and the senser's impedance is 32k. Also the minimum A/D
reference voltage is 2.5 (2.2 with accuracy loss) so for a full scale 10-bit
result you will need to scale your input up some amount.

As far as converstion accuracy goes the PIC's A/D converter is rated at
-+1 LSB at Vref = 5.0V.

Well, this is about the limit of my knowledge! I hope others can reply.

Matthew.

-- 
"I am a Liberal because I prefer progress to stagnation; because I place the
happiness of the many above the privileges of the few; and because I believe
that disasterous revolutions are best averted by timely reforms."
                              -- George Osborne Morgan
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