CAV424

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

July 2014 – Rev. 3.0

Page 5/14

www.analogmicro.de

Output Stage

Adjustable Gain

G

1

Output Current

IOUT

Source, Sink

8)

-100

100

µA

Resistive Load at Pin VOUT

RL

40

kΩ

Capacitive Load at Pin VOUT

CL

100

pF

Input Offset Voltage

VOFS

RL = 100 MΩ

-2

2

mV

Reference VREF

Reference Voltage

VREF

VREF = VCC / 2

2.49

2.5

2.51

V

Temperature Coefficient

TCVREF

dVREF /(dT·VREF), Tamb = –40...+105°C

±50

ppm/°C

Current

IVREF

Source, Sink

8)

-100

100

µA

Load Capacitance

CVREF

80

100

120

nF

Temperature Sensor VTEMP

Output Voltage

VTEMP

RTEMP≥ 50 MΩ

2.20

2.32

2.45

V

Sensitivity

S

S = dVTEMP / dT, RTEMP≥ 50 MΩ

8

mV/°C

Resistive Load

RTEMP

10

MΩ

Thermal Nonlinearity

NLTEMP

RTEMP≥ 50 MΩ, end point meth.

0.5

%

Notes:

1)

If a small deviation (< 1%) from equation (8) (or (11) resp.) is needed, a maximum measurement capacitance

CM,max not larger than ten times the particular minimum measurement capacitance CM,min should be used.

2) The specified value doesn’t include parasitic IC capacitance (typ. 5 pF for SO16(n) package at pin 12, 14 and 16).

3) If VCC ≠ 5 V, the maximum of VOUT is given by 0.8·VCC.

4) The temperature coefficient is normalized with VSpan = VOUT(CM,max) - VOUT(CM,min).

5) The maximum input signal frequency fSIG,max is defined as the measurement capacitance’s change rate, at which

the low pass filter reduces the output voltage by 6 dB.

6) The response time is defined as the time until VOUT reaches 99.99% of its final value after a 100 % input step.

7) The typical dimensioning of the low pass capacitors CF1 and CF2 is based on the requirement that a ripple of less

than 1‰ remains on the output voltage at the oscillator frequency. Smaller capacitances can be chosen to de-

crease the response time but lead to a higher ripple.

8) Currents flowing into the IC have a negative sign.

2. Absolute Maximum Values

Parameter

Symbol

Condition

Min.

Typ.

Max.

Unit

Maximum Supply Voltage

VCCmax

6

V

Maximum Oscillator Charge Current

IOSCmax

50

µA

Max. Meas. Oscillator Charge Current

ICMmax

25

µA

Max. Ref. Oscillator Charge Current

ICRmax

25

µA

Storage Temperature

TStore

-55

125

°C

ESD Susceptibility

VESD

HBM

2

kV

Notes:

1)

ESD Protection on all pins except pin 12, pin 14 and pin 16.

Table 1: CAV424's electric specifications

Table 2: Absolute Maximum Values