FEATURES
• large measurement capacitance input
range: 10pF up to 10nF
• ratiometric voltage output
• linear transfer function
• adjustable offset and gain
• fast response time
• measurement oscillator frequency:
1kHz-240kHz
• integrated temperature sensor
• supply voltage 5V ± 5%
• large temperature range:
–40°C...+105°C
• easy-to-use calibration procedure
(Excel–sheet)
• available in SO16 or as die
• RoHS conform
BLOCK DIAGRAM
GENERAL DESCRIPTION
CAV444 is an integrated C/V converter suitable for
the signal-processing in capacitive sensor systems. Its output voltage is a linear function of the
connected measurement capacitance CM and ratiometric to the supply voltage.
The IC is completely analog leading to a fast response time and a resolution only limited by the
signal to noise ratio.
CAV444 provides the complete electronics needed
for the conversion of capacitive input signals into
voltage output signals, which can be amplified and
offset adjusted using external trimming resistors.
The IC can be used as stand-alone analog signalprocessing IC or as front-end for a micro processor
for electronically calibratable sensor systems.
An Excel-sheet simplifies the external component’s
dimensioning as well as the trimming of complete
sensor systems.