A temperature sensor with 3σ inaccuracy of +0.5/-0.75 °C and energy per conversion of 0.65 μJ using a 0.18 μm CMOS technology

Author

Yucetas, Mikail ; Pulkkine, Mika ; Gronicz, Jakub ; Halonen, Kari

Author_Institution

Dept. of Micro- & Nanosci., Aalto Univ., Aalto, Finland

fYear

2013

fDate

11-12 Nov. 2013

Firstpage

1

Lastpage

4

Abstract

We present an integrated temperature sensor, which utilises bipolar transistors present in a 0.18pm CMOS process. A bipolar transistor is biased with two different current densities consecutively to have a voltage proportional to absolute temperature (PTAT). Two such bipolars are used to achieve a differential signal. The differential PTAT signal is fed to an incremental ΔΣ ADC to have temperature information in digital domain, which is then processed with an on-chip DSP block. The whole sensor can be put into power down mode after a conversion is done. The sensor operates in the temperature range from -40 °C to +85 °C. The energy per conversion is 0.65 μJ when the sensor output rate is at 3 conversions/s. The inaccuracy of the sensor is +0.5/-0.75 °C (3σ) after three point fitting.

Keywords

CMOS integrated circuits; MOSFET; analogue-digital conversion; bipolar transistors; current density; delta-sigma modulation; digital signal processing chips; temperature sensors; CMOS technology; bipolar transistor; current density; differential PTAT signal; energy 0.65 muJ; incremental ΔΣ ADC; integrated temperature sensor; on-chip DSP block; proportional to absolute temperature; size 0.18 mum; temperature -40 degC to 85 degC; three point fitting; Bipolar transistors; CMOS integrated circuits; CMOS process; Capacitors; Temperature measurement; Temperature sensors;

fLanguage

English

Publisher

ieee

Conference_Titel

NORCHIP, 2013

Conference_Location

Vilnius

Type

conf

DOI

10.1109/NORCHIP.2013.6702033

Filename

6702033