Low temperature error thermal sensor
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsJaw-Juinn Horng, Szu-Lin Liu
Life of this patent
Estimating the term…
Abstract
A thermal sensor in some embodiments comprises two temperature-sensitive branches, each including a thermal-sensing device, such as one or more bipolar-junction transistors, and a current source for generating a current density in the thermal-sensing device to generate a temperature-dependent signal. The thermal sensor further includes a signal processor configured to multiply the temperature-dependent signal from the branches by respective and different gain factors, and combine the resultant signals to generate an output signal that is substantially proportional to the absolute temperature the thermal sensor is disposed at.
Claims12
A thermal sensor, comprising:
- a temperature-sensitive device comprising a bandgap thermal-sensing device;
- a first current source adapted to generate a current of a first value;
- a second current source adapted to generate a current of a second value different from the first value;
- a first switching device (SW1) adapted to pass the current generated by the first current source through the bandgap thermal-sensing device;
- a second switching device (SW2) adapted to pass the current generated by the second current source through the bandgap thermal-sensing device;
- the bandgap thermal-sensing device being adapted to generate a first and a second output signals responsive to temperature and the current of the first and second values, respectively;
- a third switching device (SW3);
- a gain circuit operatively connectable in parallel to the bandgap thermal-sensing device through the third switch and adapted to adjust the first or second output signal when connected to the bandgap thermal-sensing device;
- and
- a signal processing circuit operatively connected to receive the first and second output signals, and to generate an output signal based on the first and second output signals.
Dependencies are inferred from the claim text.