DEMOKIT-LG2 Renesas Electronics America, DEMOKIT-LG2 Datasheet - Page 22

• Manufacturer Part Number: DEMOKIT-LG2
• Description: KIT DEMO 78K0 LG2 UPD78F0397
• Manufacturer: Renesas Electronics America

Specifications of DEMOKIT-LG2

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

DemoKit-LG2 User’s Manual
16
internal interrupt is generated. The capture value is read using this interrupt. In the next step, the C
capacity will be discharged again. The same procedure starts once more with port P03. This time the
capacitor is charged via the unknown resistor R
reached again the second timer value is read out.
The unknown R
from the two values obtained using the method described earlier.
The threshold level of the Schmitt-trigger input does not have any influence on the accuracy of the
measurement, as this will be a constant for both measurements.
VAR,
R
R
V
C
REF
VAR
and consequently the resistor value of the temperature sensor, can be calculated
= V
: R
: R
CVAR
6
5
= V
+ R
= V
CREF
T
= V
CREF
= V
CREF
= const
DD
= V
VAR
1 - e
DD
of the temperature sensor and after the threshold is
1 - e
-
R
REF
t
-
REF
R
x C
VAR
t
VAR
x C
18