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Download
PSØ21
datasheet
as Acrobat PDF:
/ 
(~870 KB, May 2005) | |
| PSØ21
has the capability to measure besides strain gages also capacities. PICOCAP measuring
principle is a direct derivate of the PICOSTRAIN measuring principle. The measuring
capacitor and a reference capacitor build together with a resistance an RC network.
They ratio of the capacities is given through the ratio of discharge times. Patent
pending algorithms provide a good suppression of parasitic capacities and ensure
a very good temperature stability. | |
|
Advantage
PICOCAP Capacitance-to-Digital Converter: - Wide
capacitance range from pF up to several nF
- High
measuring rates up to 50 kHz
- High
precision up to
20 ENOB@5Hz or
13 ENOB@10kHz - Low
current consumption down to the µA range at low measuring rates
- Patent
pending gain compensation offers temperature drift of only about 6ppm/K
- Up
to 4 sensors (without gain compensation)
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There
are 3 ways to connect the capacitors:
| -
Floating capacitors |  |
| Advantage:
Very simple circuit, up to 4 sensors Disadvantage:
C not grounded, no compensation |  | -
Grounded capacitors | | Advantage:
Very simple circuit, up to 4 sensors Disadvantage:
Lower resolution (1 Bit), resistors introduce temperature drift (use voltage dividers),
no compensation | | -
Compensated Measurement |  |
| Advantage:
minimum gain and offset drift Disadvantage:
only with 1 sensor | | |
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