The frequency generator allows an external complex impedance (range 100 Ω to 10 M Ω) to be excited with a known frequency of up to approximately 100 kHz. The response signal from the impedance is sampled by the on-board ADC and DFT processed by an on-board DSP engine.
The DFT algorithm returns a real (R) and imaginary (I) data word at each frequency point, (in the case of a sweep) allowing impedance to be conveniently calculated based on an initial system calibration.
Impedance Converter Selection Table
|Part #||Impedance Range||Resolution (Bits)||Power Supply||Temperature Range||Sampling Speed||On Chip Oscllator||Temp Sensor||Price
|AD5933||100 Ohms to 10 MOhms||12||3 V / 5 V||-40°C to 125°C||1 MSPS||Yes||Yes||$6.65||Order Samples|
|AD5934||100 Ohms to 10 MOhms||12||3 V / 5 V||-40°C to 125°C||250 kSPS||-||-||$4.35||Order Samples|
Recent Developments for SAR and Sigma Delta ADCs (Industrial Control DesignLine)
Which ADC Architecture Is Right for Your Application? (Analog Dialogue, June 2005)
Please contact the IDC Development Group.