Temperature sensor with digital bandgap
View Patent ↗A system comprises a temperature sensor generate multiple base-emitter voltage signals by sequentially providing various currents to a transistor, and a system controller to determine a differential voltage signal according to the multiple base-emitter voltage signals, the differential voltage signal proportional to an environmental temperature associated with the transistor.
1. A method comprising:
generating multiple base-emitter voltage signals by sequentially providing various currents to a transistor;
determining a differential voltage signal according to the multiple base-emitter voltage signals, the differential voltage signal proportional to an environmental temperature associated with the transistor;
generating a first base-emitter voltage signal when a first current signal is provided to the transistor;
generating a second base-emitter voltage signal when a second current signal is provided to the transistor;
determining a difference between the first base-emitter voltage signal and the second base-emitter voltage signal;
determining the differential voltage signal, at least in part, according to the determined difference between the first base-emitter voltage signal and the second base-emitter voltage signal;
generating a third base-emitter voltage signal when a third current signal is provided to the transistor;
determining difference between at least one of the first base-emitter voltage signal and the third base-emitter voltage signal or the second base-emitter voltage signal and the third base-emitter voltage signal; and
determining the differential voltage signal, at least in part, according to the determined difference between at least one of the first base-emitter voltage signal and the third base-emitter voltage signal or the second base-emitter voltage signal and the third base-emitter voltage signal;
wherein determining the differential voltage signal includes averaging multiple differences determined between various base-emitter voltage signals.
2. The method of claim 1 wherein the multiple base-emitter voltage signals are analog base-emitter voltage signals; and
converting the analog base-emitter voltage signals to digital base-emitter voltage signals for use in determining the differential voltage signal.
3. The method of claim 1 wherein converting the analog base-emitter voltage signals to digital base-emitter voltage signals is performed by a passive analog-to-digital converter.
4. A system comprising:
means for generating multiple base-emitter voltage signals by sequentially providing various currents to a transistor;
means for determining a differential voltage signal according to the multiple base-emitter voltage signals, the differential voltage signal proportional to an environmental temperature associated with the transistor
means for generating a first base-emitter voltage signal when a first current signal is provided to the transistor;
means for generating a second base-emitter voltage signal when a second current signal is provided to the transistor;
means for determining a difference between the first base-emitter voltage signal and the second base-emitter voltage signal;
means for determining the differential voltage signal, at least in part, according to the determined difference between the first base-emitter voltage signal and the second base-emitter voltage signal;
means for generating a third base-emitter voltage signal when a third current signal is provided to the transistor;
means for determining difference between at least one of the first base-emitter voltage signal and the third base-emitter voltage signal or the second base-emitter voltage signal and the third base-emitter voltage signal;
means for determining the differential voltage signal, at least in part; according to the determined difference between at least one of the first base-emitter voltage signal and the third base-emitter voltage signal or the second base-emitter voltage signal and the third base-emitter voltage signal;
means for averaging multiple differences determined between various base-emitter voltage signals to determine the differential voltage signal.
5. The system of claim 4 wherein the multiple base-emitter voltage signals are analog base-emitter voltage signals and further comprising a means for converting the analog base-emitter voltage signals to digital base-emitter voltage signals for use in determining the differential voltage signal.