Junction Temperature Validation using an A/D and a Voltage Proportional to Temperature Circuit
Original Publication Date: 2002-Apr-10
Included in the Prior Art Database: 2002-Apr-10
Junction temperatures and self-heating of semiconductor devices can be measured using an A/D and voltage proportional to temperature circuit. These circuits are calibrated so that an increase in temperature of one degree Kelvin is proportional to one least significant bit of the A/D. While the part is idle and consuming very little current the A/D and temperature circuits are calibrated to a specific ambient temperature and the conversion result recorded. Then, while maximum current is being consumed by the operating part, a second conversion is performed until the conversion result is stable. The difference between idle and operating mode results represents the self heating of the part when consuming current and is the temperature to which the device junctions are elevated above ambient when operating.