Thermoflagger™ devices offer a simple and cost-effective, low-power solution capable of connecting to multiple PTC thermistors. Additional over-temperature protection solutions can be implemented by combining them with integrated circuits for general-purpose temperature sensors.
Two devices have been announced. These are the TCTH021BE, which has a non-latching function for the FLAG signal when it detects abnormal states, and the TCTH022BE, which has a latching function for the signal.
The new TCTH021BE and TCTH022BE Thermoflagger™ each have a built-in current source and are used in conjunction with PTC thermistors that significantly increase their ohmic resistance values once a certain temperature level is exceeded. A temperature increase near any PTC will cause the voltage at the PTCO pin to rise, triggering the FLAG signal and thus detecting an over-temperature condition. By connecting multiple thermistors in series, it is possible to easily detect over-temperature at several locations.
The products are housed in the small, standard SOT-553 package (Toshiba package name: ESV), which measures only 1.6 mm x 1.6 mm x 0.55 mm. They feature a low current consumption (IDD10U) of 11.3 μA (typical) and a selectable PTCO output current. Typically, the PTCO is 10 μA with a high accuracy of ±8%.
The operating supply voltage (VDD) can be in the range of 1.7 to 5.5V and the devices can operate at temperatures between -40ºC and +125ºC.
Both products allow users to easily configure over-temperature detection for an entire electronic device without significantly impacting the device's size or power consumption. Both products in the TCTH0xxxE series will be available starting today.
