Over Temperature Protection Ic

Idea super brigth led light will include 100 leds which consume 1 watt per led.

Over temperature protection ic.

White paper intelligent over temperature protection for led lighting applications 01 october 2013 7 4 ic implementation of smart over temperature protection leveraging the key idea of a patent to use the led driver ic as a thermal sensor a patent pending technology has been developed to protect the leds with a slope dimming characteristic and. The 1n4007 diode has forward voltage drop of 0 7 v so it will provide the extra 0 7 v drop. Ic data sheets often give some informations about the circuits over temperature protection. Once the ptc cools down it permits the current to flow again.

A circuit is used to monitor and generate a trigger signal that starts the shutdown process at the high temperatures. This characteristic is self regulating. The resistance of ptc thermistors rises rapidly when a certain temperature is exceeded thus stopping the flow of current. Often the primary protection and gas gauge components are combined into a single ic which may include additional protection features not shown above like over under temperature protection and battery authentication.

Lets take a microchip ldo mcp1702 for example. Over temperature protection otp 6. The same method is used in the design of this battery over charging protection circuit. Over operating free air temperature range unless otherwise noted 1 min max unit in pgate with respect to vss 0 3 30.

If the power dissipation within the ldo is excessive the internal junction temperature will rise above the typical shutdown threshold of 150 c. The diagram below shows the replacement of a temperature sensor ic with an ntc thermistor. I made simple over temperature protection circuit which will shut down leds when a certain temperature is reached. Bq24308 overvoltage and overcurrent protection ic and li charger front end protection ic 1 features 3 description the bq24308 device is a highly integrated circuit ic.

That is why there will be a lot of dissipating heat. For example a zener diode of 7 v can be used in series with a 1n4007 diode. The secondary protection is composed of the secondary safety ptc tco and nonresettable fuse blocks. Usually power supplies have a monitoring integrated circuit on their secondary see figure 1 which is in charge of the power supply protections.

The accuracy of a relatively simple temperature detection circuit consisting of an ntc thermistor and fixed resistors is fully sufficient for the protection of an hdd and much more cost efficient than a circuit using a temperature sensor ic. Over temperature protection in a power supply is a protection system that shuts down the power supply when the internal temperature exceeded a safe value.