OSRAM OPTOTRONIC Constant current LED power supplies with 3DIM - Manual (Page 36)

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3.3.2.2. Application solution 2 –
overtemperature management by comparator: two-step output
The following application is basically similar to the one described in
chapter 3.3.1.6. Application solution 6 – TC620(1) solution. The
circuit is obtained by using a low-cost dual OPAMP, which allows
setting two trip temperatures (Tset
H
and Tset
L
) and their relative
hysteresis by extending the circuit functionality described in chapter
3.3.2.1. Application solution 1 – over temperature protection by
comparator.
LEDset APPLICATIONS
Figure 31: Thermal derating – NTC + OPAMP solution: two-step output – schematic. Figure 32: NTC + OPAMP solution: two-step output – characteristic.