The THS3470 over temperature flag, OVTEMP_FLAG, is used to monitor when the internal thermal shutdown of the device is active. The OVTEMP_FLAG typically asserts low when the die temperature exceeds 160 degrees, depending on process variation of the device. After asserting the flag low, the flag typically asserts high when the device temperature cools to 140 degrees, also dependent on process variation, to create a hysteresis window to prevent the device from continuously asserting an de-asserting.

There are two primary use cases for the over temperature flag. The typical use case is to connect the OVTEMP_FLAG directly to the P0 and P1 pins to allow the device to thermally shutdown when the die temperature is too hot. Additionally, if one of the other power modes is desired on the P0 and P1 pins, a logical AND gate can be used with the preferred P0 and P1 bias states. The second use case is to connect OVTEMP_FLAG to a digital input/output pin of a micro controller and monitor the pin as a temperature warning flag. In this case, the micro controller can make decisions, along with the DIE_TEMP pin, to toggle the P0 and P1 pins earlier or later than when the P0 or P1 pins are tied to the OVTEMP_FLAG to more tightly control the thermal regulation of the THS3470.

Figure 6-4 OVTEMP_FLAG Schematic