A Low power integrated temperature sensor with digital outputs for on-chip temperature monitoring applications

Download
2017
Turan, Özge
This thesis presents the design and implementation of a low power temperature sensor with digital outputs for on-chip temperature monitoring applications. The temperature sensor is based on the substrate bipolar transistor which generates the bandgap reference voltage and proportional to absolute temperature (PTAT) voltage. The bandgap reference voltage is temperature and supply independent thus it is used to generate the reference signals for Analog to Digital Converter (ADC), while the PTAT voltage generated by the temperature sensor is connected to the input of the ADC. The ADC is implemented with a Successive Approximation Register (SAR) ADC, which converts the analog temperature signal to a 12-bit digital data. The SAR ADC with a split capacitive array Digital to Analog Converter (DAC) is chosen for low power and low area advantages for medium resolution applications. All the bias voltages and bias currents are generated with respect to the reference currents that are generated from the bandgap voltage. The configuration of the bias signals and operation specifications are all configurable through the Serial Programming Interface (SPI). The digital controller provides the communication with external electronics through SPI, controlling the process parameters via configuration memory and on-chip calibration. The on-chip calibration is designed to compensate the errors coming from predominantly small temperature variations of the ADC bias voltages generated in the bias generator, ADC noise, comparator offset voltage, and nonlinearity of PTAT voltage. The output data format is a serial 12-bit data generated by the output serializer block. The number of output pads decreased by a serializer block, reducing the required power and area. The external pins include only power and SPI communication pins. The operation region of the temperature sensor is between -55 ºC to 125 ºC. A resolution of 0.08 ºC is achieved by the 12-bit SAR ADC. The total power consumption of the full chip is at most 2 mW with a 3.3 V power supply. The full chip is designed and implemented using a 0.35 μm CMOS process in an area of the 2 mm × 2 mm, and it is submitted to a multi-project wafer (MPW) run for fabrication.  

Suggestions

A thermal conductivity based humidity sensor in a standard CMOS process
Okean, B; Akın, Tayfun (2004-01-29)
This paper presents a low-cost, thermal conductivity based humidity sensor implemented using a 0.6 mum CMOS process where suspended p-n junction diodes are used as the humidity sensitive elements. In this method, the difference between the thermal conductivities of air and water vapor at high temperatures is used. Humidity sensing idea is to compare the output voltages of two heated and thermally isolated diodes one of which is exposed to the environment and has a humidity dependent thermal conductance whil...
A Miniature Low-Cost LWIR Camera with a 160x120 Microbolometer FPA
Tepegoz, Murat; Kucukkomurler, Alper; Tankut, Firat; Eminoglu, Selim; Akın, Tayfun (2014-05-08)
This paper presents the development of a miniature LWIR thermal camera, MSE070D, which targets value performance infrared imaging applications, where a 160x120 CMOS-based microbolometer FPA is utilized. MSE070D features a universal USB interface that can communicate with computers and some particular mobile devices in the market. In addition, it offers high flexibility and mobility with the help of its USB powered nature, eliminating the need for any external power source, thanks to its low-power requiremen...
A Digitally programmable application specific integrated circuit for drive and data acquisition of imaging sensorsMethod of moments analysis of slotted waveguide antenna arrays
Bayhan, Nusret; Akın, Tayfun; Eminoğlu, Selim; Department of Electrical and Electronics Engineering (2014)
This thesis explains the implementation of a digital programmable Application Specific Integrated Circuit (ASIC) designed for imaging applications. The primary function of this ASIC is to drive imaging sensors and to do basic processing on the digital video data coming from the sensors. The ASIC is designed to handle the communication between the imaging sensor and the system. Using command based high-level instructions, this two-way communication is simplified. The ASIC can also be used to store and update...
A Low-power memory CMOS integrated circuit for image sensors
Üstündağ, Mithat Cem Boreyda; Akın, Tayfun; Department of Electrical and Electronics Engineering (2015)
This thesis presents a low power SRAM block implemented in a 0.35 μm CMOS technology for imaging applications to be used inside a digital image processor ASIC (Application Specific Integrated Circuit). The SRAM structure is designed to be fast enough to store all the image data fed by a large format readout circuitry such as VGA (640x512), while requiring low power consumption. The low power consumption is a very critical requirement of such circuit, as the circuit will eventually be used in an embedded pla...
A Small format microbolometer imaging sensor with digital video outputs
Yalçın, Cem; Koç, Seyit Sencer; Department of Electrical and Electronics Engineering (2016)
This thesis presents a small format Readout Integrated Circuit (ROIC) for surface micromachined resistive microbolometer imaging sensors. The imaging sensor is designed to work in the Long Wave Infrared region (8 – 14 um) and is designed with an 80 x80 format with a pixel pitch of 25 um. The ROIC is optimized to perform the readout of MEMS pixels with resistance values around 60 Kohm, where infrared blind reference resistors with similar values are also used to cancel effects of selfheating and high biasi...
Citation Formats
Ö. Turan, “A Low power integrated temperature sensor with digital outputs for on-chip temperature monitoring applications,” M.S. - Master of Science, Middle East Technical University, 2017.