A PTAT Voltage Source consisting of Subthreshold MOSFETs for Temperature Sensor LSIs

An ultra-low power temperature sensor circuit based on a subthreshold MOSFET was proposed. The sensor consists of a modified β-multiplier self biasing circuit that uses a switched capacitor resistor instead of ordinary resistors. The circuit is operated in the subthreshold region, and it generates a proportional to absolute temperature (PTAT) voltage. Simulation with SPICE demonstrated that the circuit can be used as a smart temperature sensor with ultra-low power consumption of 3.5 ㎼ or less. The accuracy of the sensor output was within ±1.5℃.

[1]  Kofi A. A. Makinwa,et al.  A CMOS smart temperature sensor with a 3σ inaccuracy of ±0.1°C from -55°C to 125°C , 2005, IEEE J. Solid State Circuits.

[2]  Yuan Taur,et al.  Fundamentals of Modern VLSI Devices , 1998 .

[3]  Chun-Chi Chen,et al.  A time-domain SAR smart temperature sensor with −0.25∼+0.35°C inaccuracy for on-chip monitoring , 2008, ESSCIRC 2008 - 34th European Solid-State Circuits Conference.

[4]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.