Register now for the most anticipated Asia Pacific Power Seminar 2022

Tip / Sign in to post questions, reply, level up, and achieve exciting badges. Know more

LED Driver ICs Forum Discussions

25 sign-ins 5 questions asked First question asked
A thermal protection circuitry is integrated in the LITIX™ Basic+ devices. It is realized by a temperature monitoring of the output stages.
The reaction is different for the TLD2x3x-xEP /TLD214x-xEP and the TLD2252-2EP /TLD1114-1EP devices:

TLD2x3x-xEP, TLD214x-xEP
As soon as the junction temperature exceeds the current reduction threshold _T_j(CRT) = 140°C [P_6.5.44], the device reduces the IN_SETx reference voltage, VIN_SETx(ref) [P_6.6.1]. Since the IN_SET current is function of the IN_SET reference voltage, it decreases as well according to IIN_SETx(ref) = VIN_SETx(ref)/RSETx.
If the device temperature still increases, the output current decreases close to 0 A. As soon as the device cools down the output current rises again.
Note: the thermal foldback works only when the IN_SET is connected to a resistor and not to a regulated current sink.

TLD2252-2EP, TLD1114-1EP
As soon as the junction temperature exceeds the overtemperature threshold TJSD = 175°C (typ) [P_6.5.42], the output is disabled and the IN_SET pin goes in a weak pull-down state with a current consumption IIN_SET(fault) = 10 uA [P_7.5.1].
If the temperature cools down below TJSD - TJ(hys) = 175°C - 10°C [P_6.5.43], the IN_SET rises again to VIN_SET(ref) [P_6.6.1] within an additional time tIN_SET(del) [P_7.5.4]. Consequently, the output current rises again.
The overtemperature condition is reported to the ERRN pin and can be used to deactivate other LITIX™ Basic+ devices connected to the same ERRN network.

For more information check the LITIX™ Basic+ webpage.
0 Replies