CAV424

C/V-converter for single and differential capacitive input signals

July 2014 – Rev. 3.0

Page 3/14

www.analogmicro.de

FEATURES

•

large measurement capacitance range:

5 pF up to 40 nF

•

suitable for single and differential capaci-

tive sensor heads

•

high detection sensitivity

•

ratiometric voltage output

•

adjustable offset and gain

•

fast response time

• 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

GENERAL DESCRIPTION

CAV424 is an integrated C/V-converter suitable

for the capacitance measurement in single or

differential capacitive sensor systems. Its output

voltage is a linear function of the reciprocal meas-

urement capacitance and it is ratiometric to the

supply voltage.

The IC is completely analog leading to a fast re-

sponse time and a resolution only limited by the

signal to noise ratio.

CAV424

provides

the

complete

electronics

needed for the conversion of single or differential

capactive input signals into voltage output signals,

which can be an amplified and offset adjusted

using external trimming resistors.

The IC can be used as stand-alone analog signal-

processing IC or as front-end for a micro proces-

sor for electronically calibratable sensor systems.

An Excel-sheet simplifies the external compo-

nent’s dimensioning as well as the trimming of

complete sensor systems.

BLOCK DIAGRAM

Figure 1: CAV424's block diagram