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AN T001

SEMICONDUCTOR SENSOR APPLICATION NOTE

AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
Figure 1. Overview of recommended supplementary resistors for a curve shift at room temperature for the KTY1x-series
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
KTY RS
KKTY: Temperature coefficient
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
RT: Resulting resistance value RS: Serial resistor
This Resistor value of RS is dedicated to application temperatures close to room temperature. The more the temperature deviates from the room temperature, the more the resistance value is varying from the nominal KTY10-7 curve. To minimize the error in resistance, it is advantageous to set up its value close to the target temperature resistance or in the center of the working temperature band :
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
The error of the modified KTY10-6-curve to the KTY10-7 is obtained by: (average resistance values)
5000 4500 4000 resistance (ohm) 3500 3000 2500 2000 1500 1000 500 0 -50 0
80 100 temperature (°C)
Figure 2. Error vs. temperature with a serial resistor optimized for a target temperature of 80°C
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
In the case of a parallel arrangement the resistance value can be obtained by:
RKTY 10-6 (T A ) RKTY 10-5 (T A ) RKTY 10-6 (T A ) - RKTY 10-5 (TA )
The error in the modified KTY10-6-curve to the KTY10-5 is obtained by : (average resistance values)
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
80 100 temperature (°C)
resistance (ohm)
Figure 3. Error vs. temperature with a parallel resistor optimized for a target temperature of 80°C
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
Al or electrical isolating but thermal sufficiently conducting materials (e.g.Ceramics)
TO-92
TO-92 Mini
Figure 4. Cross section of feasable thermal coupling components (cylindric parts) In high voltage applications according to VDE (Association for Electrical, Electronic & Information Technologies) it is prohibited to use electrically conducting materials at a distance less than 3.5 mm next to connection wires of the temperature sensor. This is with regard to a limited breakdown voltage. Therefore, additional isolation will be required. Because of the longer thermal time constant of the TO-92 package in many cases it is necessary to use an aluminium sleeve to give sufficient thermal coupling. Due to a decreased thermal time constant of the shrunk (TO-92 TO-92 Mini ) package it would be possible to use electrically isolating materials and hence fullfill the VDE requirements.
Infineon Semiconductor Sensor Group
AN T001
SEMICONDUCTOR SENSOR APPLICATION NOTE
TO-92
TO-92 Mini
TO-92 Mini adapted to TO-92
Figure 5. cross section of the TO-92 packages and a TO-92 Mini adaption scheme
Infineon Semiconductor Sensor Group