OSRAM OPTOTRONIC Constant current LED power supplies with 3DIM - Manual (Page 24)

24
3.3.1. Overtemperature protection
3.3.1.1. Application solution 1 – TMP300 solution
A possible approach for overtemperature protection is to
simply use the so-called “temperature switch ICs” – an easy,
relatively cheap and low-component-number solution.
TMP300 (Texas Instruments) is a digital output temperature
switch IC. Its voltage supply range is 1.8–18 V, therefore it
can be directly supplied by the LEDset +12Vset terminal.
The open drain output is to be connected to the Vset termi-
nal of the LEDset interface, thus obtaining the ECG shut-
down when the temperature of the LED module exceeds a
certain Tset
TH
(temperature threshold).
The trigger temperature Tset
TH
can be set between -40 °C
and +125 °C by an external resistor (Rtemp), calculated as
follows:
The following chapters provide some example solutions of
different simple implementations realized by commercially
available ICs with integrated temperature sensing capability. A
schematic reference shows their interface with LEDset ECGs.
LEDset APPLICATIONS
Figure 13: Thermal protection – TMP300 solution.
Rtemp
[
kΩ
]
10 ( 50 + Tset
TH
)
3
For more information, please see the general notes on page 33.