Inter national J our nal of Electrical and Computer Engineering (IJECE) V ol. 8, No. 2, April 2018, pp. 946 – 953 ISSN: 2088-8708 946       I ns t it u t e  o f  A d v a nce d  Eng ine e r i ng  a nd  S cie nce   w     w     w     .    i     a    e    s    j    o    u    r    n    a    l     .    c     o    m     CMOS T emperatur e Sensor with Pr ogrammable T emperatur e Range f or Biomedical A pplications Agung Setiab udi 1 , Hir oki T amura 2 , and K oichi T anno 3 1 Department of Materials and Informatics, Uni v ersity of Miyazaki, Japan 2 Department of En vironmental Robotics, Uni v ersity of Miyazaki, Japan 3 Department of Electrical and System Engineering, Uni v ersity of Miyazaki, Japan Article Inf o Article history: Recei v ed Dec 11, 2017 Re vised Jan 20, 2018 Accepted: Feb 19, 2018 K eyw ord: Biomedical Application Programmable T emperature Sensor Digital CMOS Lo w-po wer Lo w-v oltage. Abstract A CMOS temperature sensor circuit with programmabl e temperature range is proposed for biomedical applications. The proposed circuit consists of temperature sensor core circuit and programmable temperature range digital interf ace circuit. Both circuits are able to be operated at 1.0 V . The proposed temperature sensor circuit is operated in weak in v ersion re gion of MOSFETs. The proposed digital interf ace circuit con v erts current into time using Current-to-T ime Con v erter (ITC) and con v erts time to digital data using counter . T empera- ture range can be programmed by adjusting pulse width of the trigger and clock frequenc y of counter . The proposed circuit w as simulated using HSPICE with 1P , 5M, 3-wells, 0.18- m CMOS process (BSIM3v3.2, LEVEL53). From the simulation of proposed circuit, temperature range is programmed to be 0 °C to 100 °C, it is obtained that resolution of the proposed circuit is 0.392 °C with -0.89/+0.29 °C inaccurac y and the total po wer consump- tion is 22.3 W in 25 °C. Copyright © 2018 Institute of Advanced Engineering and Science . All rights r eserved. Corresponding A uthor: K oichi T anno Department of Electrical and System Engineering, Uni v ersity of Miyazaki 1-1 Gakuenkibanadai-nishi, Miyazaki, 889-2192, Japan tanno@cc.miyazaki-u.ac.jp 1. INTR ODUCTION Engineering is an inno v ati v e field that its origin ideas leading to e v erything, including biology and medical area. Applicat ion of engineering in biology and medical area is then called biomedical e n gi neering. The purpose of this field is combining the design and problem solving skills of engineering with medical and biology sciences to adv ance health care treatment, including diagnosis, monitoring, and therap y [1]. In the recent years, there is a l o t of research focus on biomedical engineering. This topic is becoming interesting and challenging due to t he increase of system comple xity , human population and its distrib ution. One of the most important components in biomedical engineering is sensor . This component is v ery impor - tant because it is directly connected to ph ysical phenomenon [2, 3]. In man y biomedical applications, sensor plays a crucial role to collect data from man y objects such as human body temperature, en vironment humidity and oxygen le v els in the air . The often utilized sensor in biomedical applications is temperature sensor , because temperature is a highly important parameter to monitor , identify , or control man y conditions in biomedical field, such as diagnos- ing human disease, temperature monitoring in operating rooms and pre v enting bacteria gro wth in some places. By kno wing the useful of temperature sensor in man y biomedical applications, the a v ailability of a temperature sensor which can be used in v arious biomedical applications is highly recommended. The problem is dif ferent biomedical application has dif ferent temperature range to be measured. It means that the sensor must ha v e wide temperature range. Ho we v er , wide temperature range causes the resolution of its digital data decreases. T o k eep the resolution high, high-bit analog to digital (ADC) must be applied. Ne v ertheless, it will decrease the speed and increase the po wer consumption. Furthermore, in biomedical applications, not only high sensiti vity temperature sensor is needed b ut also lo w v oltage and lo w po wer temperature sensor is strongly required [4], [5], [6]. A lo w po wer and lo w v oltage temperature sensor has been proposed and reported [7], [8]. This sensor in J ournal Homepage: http://iaescor e .com/journals/inde x.php/IJECE       I ns t it u t e  o f  A d v a nce d  Eng ine e r i ng  a nd  S cie nce   w     w     w     .    i     a    e    s    j    o    u    r    n    a    l     .    c     o    m     ,  DOI:  10.11591/ijece.v8i2.pp946-953 Evaluation Warning : The document was created with Spire.PDF for Python.
IJECE ISSN: 2088-8708 947 general achie v es lo w po wer c o ns umption, b ut it has small sensiti vity . The other high sensiti vity temperature sensors are also proposed [9], [10]. Ho we v er , these sensors are not lo w v oltage and it consumes high po wer . The other problem is that man y con v entional on-chip temperature sensor circuits use BJT ( V be ) to sense temperature [4], [9], [11], [12]. The problem of BJT is not able to be implemented in the same chip in man y standard CMOS processes. This means that cost of f abrication will increase. The last problem is that man y cores of temperature sensor circuits use e xternal bias circ uits or high v alue resistor [8], [9], [13]. These require lar ge chip areas. A lo w v oltage and lo w po wer temperature sensor circuit with digital output for health care monitoring system has been proposed in [14]. This sensor can achie v e lo w v oltage, lo w po wer , high sensiti vity and high resolution. Ho we v er , this sensor is special for health care monitoring system whose temperature range only 33 °C to 45 °C, and it can not to be used for other biomedical applications with dif ferent temperature range. This paper proposes a ne w temperature sensor circuits based on pre vious w ork [14] with addition of pro- grammable temperature range digitali zation. In this paper , the analysis of the circuits, simulation results and the measurement of f abricated temperature sensor core are reported in detail. This paper is or g anized as follo ws. The pre vious research and impro v ement are presented in Sect. 2. In Sect. 3, the simulation results of the designed circuit and measurement of f abrication temperature sensor core are presented. Finally , Sect. 4 concludes this paper . 2. PREVIOUS RESEARCH AND IMPR O VEMENT In this section, the pre vious research [14] and its impro v ement are presented in detail. Fig. 1 s ho ws the block diagram of the proposed temperature sensor in pre vious research. This proposed temperature sensor consists of some sub circuits: sensor core circuit [3], v oltage t o current con v erter (VIC) circuit, 1/x circuit, current to time con v erter (ITC) circuit [15], and counter . Figure 1. Block diagram of the proposed inte grated temperature sensor with digital output 2.1. T emperatur e Sensor Cor e Figure 2 sho ws the t emperature sensor core circuit. The temperature sensor core implementation consists of sensor block and start-up block. The start-up block ( M s 1 , M s 2 and M s 3 ) is circuit to force turn on the sensor block, and t his block does not af fect the output v oltage. The sensor block is constructed using M 1 - M 5 . Where, M 1 , M 2 and M 3 are operated in weak in v ersion re gion, whereas M 4 and M 5 can be operated in both weak and strong in v ersion re gion. I ds of the MOSFET operate in the weak in v ersion re gion is represented by the follo wing equation. I ds = I 0 W L exp V g s V th + V ds nV 1 exp V ds V (1) I 0 = 2 nC ox V 2 (2) V = k q T k (3) n = 1 + C d C ox (4) Where V is the thermal v oltage, k (= 1.38 10 23 J/K) is the Boltzmann’ s constant, q (= 1.60 10 19 C) is the electron char ge, T K is the absolute temperature, n is slope f actor , is DIBL (Drain Induced Barri er Lo wering) coef ficient, is carrier mobility , C d is capacitance of the depletion layer , C ox is capacitance of the oxide layer . In (1), if V ds 4 V , 1 exp ( V ds /V ) is satisfied, as the results exp ( V ds /V ) can be ignored. Furthermore, because it is well-kno wn that V ds is small v alue, ( V g s V th ) V ds can be satisfied. From these conditions, (1) can be re written to (5). I ds = I 0 W L exp V g s V th nV (5) CMOS T emper atur e Sensor with Pr o gr ammable T emper atur e Rang e for Biomedical ... (Agung Setiab udi) Evaluation Warning : The document was created with Spire.PDF for Python.
948 ISSN: 2088-8708 (a) (b) Figure 2. T emperature Sensor: (a) Core circuit, (b) Cascade connection of temperature sensor core V P T AT 1 = nV ln W 2 =L 2 W 1 =L 1 I 1 I 2 + V th 1 V th 2 (6) And the threshold v oltage with the body ef fect of MOSFET is generally gi v en by (7). V th = V th 0 + p j 2 F + V sb j p j 2 F j (7) Where V th 0 is the zero-bias threshold v oltage, is the body ef fect coef ficient, 2 F is the surf ace potential parameter . If V sb is small enough, (7) can be approximated as follo ws. V th V th 0 + V sb 2 p 2 F (8) From Fig. 2 (a) it can be kno wn that V sb 1 = 0 and V sb 2 = V P T AT 1 , then V P T AT 1 can be e xpressed as by (9) V P T AT 1 = nV ln W 2 =L 2 W 1 =L 1 I 1 I 2 1 + 1 2 p 2 F (9) It is assumed that = 0.61 and 2 F = 0.7, the denominator of (9) is calculated as follo ws 1 + 1 2 p 2 F = 1 : 365 n 0 (10) Slope f actor n is kno wn to be a v alue of approximately 1.5, therefore, it can be considered that n’ is relati v el y close to the v alue of n . As a result, V P T A T 1 can be e xpressed by equation (11). V P T AT 1 = n n 0 V ln W 2 =L 2 W 1 =L 1 I 1 I 2 V ln W 2 =L 2 W 1 =L 1 I 1 I 2 k q ln W 2 =L 2 W 1 =L 1 I 1 I 2 T K (11) From (11), it can be found that V P T AT 1 of the proposed circuit is directly proportional to T K . Moreo v er , it could be understood that the output v oltage of Fig. 2 is proportional to absolute temperature. The sensiti vity of the sensor can then be increased using cascade connection of the ci rcuit. Fig. 2 (b) sho ws the cascade connection of circuit Fig. 2 (a). Using (11), V P T AT n of Fig. 2 (b) is as follo ws. V P T A T n = k q ln W 12 =L 12 W 11 =L 11 I 11 I 12 T K + V P T AT n 1 (12) Using (11) and (12), VPT A T2 is then gi v en by V P T AT n = k q ln  W 2 =L 2 W 1 =L 1 I 1 I 2 + : : : + W 12 =L 12 W 11 =L 11 I 11 I 12  T K (13) From (13), since the output v oltage can be e xpressed by summation of the log arithmic term, this method can be used to increase sensiti vity ef fecti v ely . IJECE V ol. 8, No. 2, April 2018: 946 – 953 Evaluation Warning : The document was created with Spire.PDF for Python.
IJECE ISSN: 2088-8708 949 2.2. V oltage to Curr ent Con v erter (VIC) Figure 3 sho ws V oltage to Current Con v erter (VIC). From the figure it can be inferred that V m = V in , and hence the follo wing equation can be obtained. I R = V in R (14) I R is then copied by t w o current mirrors ( M v i 1 , M v i 3 , M v i 4 , and M v i 5 ) to I P T AT . If the ratio of W / L between M v i 1 Figure 3. V oltage to Current Con v erter (VIC) and M v i 3 are m and n , and M v i 4 and M v i 5 are identical, then the follo wing equation can be obtained. I P T A T = n m V in R (15) 2.3. 1/x Cir cuit and Curr ent to T ime Con v erter (ITC) Figure 4 sho ws the 1/x circuit and ITC. The 1/x circuit is formed using M t 1 , M t 2 , M t 3 , and M t 4 which are operated in weak in v ersion re gion. Based on translinear principle in weak in v ersion re gion I a can be gi v en by the follo wing equation. I a = I 2 r ef I P T AT (16) Where I r ef is current source which ha v e no temperature dependenc y , V b is supplied by reference v oltage circuit, and I P T AT is the output current of v oltage to current con v erter . Th e temperature dependence of I a is v ery s mall because it utilizes translinear principle. Figure 4. Current to T ime Con v erter (ITC) The operating principle of ITC could be described as follo ws, When V tg r sho wn in ITC circuit is lo w , M x 3 , M x 4 , and M x 5 are OFF , and the circuit is in the idle mode. Therefore, V p reaches V dd , as the result, T out becomes Lo w . When a short single pulse is a pp l ied to the g ate of M x 5 , not only M x 5 b ut also M x 3 and M x 4 become ON, CMOS T emper atur e Sensor with Pr o gr ammable T emper atur e Rang e for Biomedical ... (Agung Setiab udi) Evaluation Warning : The document was created with Spire.PDF for Python.
950 ISSN: 2088-8708 because V p becomes Lo w . As the result, I a flo w in C , and C store the char ges that are proportional I a . During this period, T out is high. The capacitor C is continuousl y char ged, and V p is i n c reasing. When V p reaches the threshold v oltage of In v 1 ( V inv 1 ), T out is lo w , M x 3 and M x 4 become OFF and M x 2 becomes ON, respecti v ely . Therefore, the char ge of C is dischar ged through M x 2 , and then the circuit returns to the idle mode. Using (16), T out can be gi v en by T out = C V inv 1 I 2 r ef I P T AT (17) From (17), it can be inferred that T out is proportional to I P T AT . T out can be con v erted to the digital v alue by counting up the period of high le v el in T out by a counter . 2.4. Pr ogrammable T emperatur e Range Digitalization In the sub section 2.3 it has been e xplained that digital v alue of the measured temperature can be obtained by counting up the high le v el period of T out by a counter . Ho we v er , if T out is directly connected to counter , it will be inef fecti v e. Because it is kno wn from equation (17) that T out is proportional to absolute temperature. It means that the high le v el of T out will appear as f ar as the temper ature is lar ger than absolute zero. In the other hand, it is well kno wn that in the biomedical applications, the measured temperature is much higher than absolute zero, for e xample the critical human body temperature is 35 °C (h ypothermia) to 41.5 °C (h yperp yre xia). Thus, if T out is directly connected to counter , the temperature range of digital con v ersion result will be dif ficult to be adjust ed. Moreo v er , the digital con v ersion will not reach high resolution. In T out -counter direct connection, the temperature range can be adjusted using clock frequenc y of the counter . The higher clock frequenc y of counter , the more narro w temperature range that can be con v ert to digital data. Oppositely to the temperature range, the resolution of digital data is higher . Ho we v er , for narro w temperature range biomedical applications, T out -counter direct connection is still not ef fecti v e w ay to be used. Because T out pulse width is start to appear right after absolute zero temperature, and increases proportionally as temperature in- creases. Therefore, if the minimum temperature of the biomedical appl ications is much lar ger than absolute zero, the unnecessary con v ersion will e xist. This problem will also mak e the adjustment dif ficult, because the counter will be o v erflo w man y times before start to con v erts desired T out pulse width. Figure 5 sho ws the desired con v ersion and unnecessary con v ersion in T out pulse width. T o mak e easier temperature range adjustment and more ef fecti v e con v ersion, unnecessary con v ersion must be eliminated. In other w ord, the counter counting up only in desired con v ersion re gion in T out pulse width. T o perform this function, the connection between T out and counter is modified. This architecture is sho wn in Fig. 6. Figure 5. Desired con v ersion in T out pulse width Figure 6. ITC-Counter connection architecture Using architecture in Fig. 6, the temperature range can be programmed or adjusted not only by clock frequenc y of the counter b ut also by pulse width of the t rigger ( V tg r ). Since V tg r is connected to R st using an in v erter , the counter will be in reset condition and it does not count up as f ar as the V tg r is high. Thus, the con v ersion only in desired temperature range can be performed by k eeping high V tg r from t 0 to t 1 sho wn in Fig. 5. The pulse width of V tg r is written in equation (18). The clock frequenc y of the counter then can be calculated using equation (19). V tg r P W = t 1 t 0 (18) f cl k = 2 N 1 t 2 t 1 (19) Where t 1 is pulse width of minimum temperature in temperature range, t 2 is pulse width of maximum temperature in temperature range, and N is resolution of the counter (bit). Generating pulse and clock with v arious IJECE V ol. 8, No. 2, April 2018: 946 – 953 Evaluation Warning : The document was created with Spire.PDF for Python.
IJECE ISSN: 2088-8708 951 width and frequenc y is an easy thing that can be performed in programmable de vices, lik e microcontroller and microprocessor . In other w ord, the temperature range of the proposed temperature sensor is easily programmable, so that it can be used in v arious biomedical applications. 3. SIMULA TION RESUL TS AND MEASUREMENT OF F ABRICA TED TEMPERA TURE SENSOR CORE The performance of the proposed circuit w as e v aluated using HSPICE with 1P , 5M, 3-well, 0.18-m CMOS process (BSIM3v3.2 LEVEL53). All simulations use 1.0 V supply v oltage. Figure 7 sho ws the simulation result of sensor core circuit in the temperature range of -40 °C to 160 °C. V P T AT 1 is output of single sensor core, and V P T AT 2 is the output of cascade connection of tw o sensor cores. From this simulation, it w as obtained that sensiti vity of single sensor core is 0.392 mV/C with 0.78 % nonlinearity . This sensiti vity could be increased using cascade connection lik e sho wn by V P T AT 2 , its sensiti vity is 0.783 mV/°C, with 0.89 % nonlinearity . Figure 7. V P T A T -T emperature characteristic Figure 8. Measurement result of f abricated sensor core Figure 9. Inaccurac y of f abricated sensor core Figure 10. Pulse width-temperature characteristic In order to v erify the performance of temperature sensor core, this temperature sensor core is f abricated using 0.6 m CMOS process. Figure 8 sho ws the a v erage measurement results of 10 dif ferent chips. From this figure it can be kno wn that the output v oltage of the temperature sensor core is proportional to temperature. The a v erage sensiti vity of 10 measured chips is 0.8343 mV/°C. Figure 9 sho ws the accurac y of f abricated temperature sensor core. From this measurement it w as obtained that its inaccurac y is -1.144/+1.059 mV or 2.70% nonlinearity . Figure 10 sho ws the relationship between temperature and pulse width. In these simulations, temperature CMOS T emper atur e Sensor with Pr o gr ammable T emper atur e Rang e for Biomedical ... (Agung Setiab udi) Evaluation Warning : The document was created with Spire.PDF for Python.
952 ISSN: 2088-8708 T able 1. A comparison of the main performance parameters of temperature sensor circuit P arameter This w ork [4] [5] [16] [17] [18] Po wer Supply(V) 1.0 3.3 0.5, 1.0 2.2 - 3 3.3 1.0 Po wer consumption( W) 22.3 429 0.119 10 - 27 10 25 Range (°C) programmable -50 to 125 -10 to 30 10 to 80 0 to 100 50 to 120 Inaccurac y (°C) -0.98 to +0.29 -0.5 to +0.5 -0.8 to +1.0 -1.8 to +1.0 -0.7 to +0.9 -1.0 to +0.8 Process ( m) 0.18 0.5 0.18 0.35 0.35 0.09 w as changed from -40 °C to 160 °C in step of 10 °C. As a result, it w as obtained that the puls e width w as proportional to temperature wi th 0.276 s/°C sensiti vity and 2.14 % nonlinearity . Based on the data from these simulations, temperature range programmability of this proposed circuit is v erified by programming its temperature range t o be 0 °C to 100 °C. Using equations (18) and (19) the pulse width of V tg r and clock frequenc y of the counter ( CP ) are 70.9 s and 9.59 MHz, respecti v ely . Figure 11. D out -temperature characteristic Figure 12. Inaccurac y of the proposed temperature sensor Figure 11 sho ws digital output of the simulati on result after the temperature range of the sensor is pro- grammed to be 0 °C to 100 °C. From the simulation it w as obtained that digital code D out is proportional to temperature. The digital code of this simulation w as 0 to 255. This means that 1 LSB is equal to 0.392 °C. Figure 12 sho ws the accurac y of the proposed inte grated temperature sensor circuit. The accurac y measurement w as done using tw o calibration points (0 °C and 100 °C). From this measurement it w as obtained that inaccurac y of t he proposed circuit is -0.98/+0.29 °C. From these simulation results it can be v erified that the temperature range of the sensor can be programmed well. The po wer consumption of the proposed circuit in 25 °C is 22.3 W . This v alue is sum of all circuits, sensor core (1.72 W), VIC (1.21 W), 1/x circuit (0.331 W), ITC (1.16 W), and counter (17.8 W). Lastly , a comparison of main performance parameters of temperature sensor is summarized in T able 1. 4. CONCLUSION In this paper , the inte grated temperature sensor circuit is constructed using sensor core, v oltage-to-current con v erter (VIC), 1/x circuit, current-to-time con v erter (ITC) and counter . Sensor core is formed using CMOS circuit operated in weak in v ersion re gion and it i s insensiti v e to de vice parameter of f abrication process. The output of the sensor is then digitized using proposed programmable temperature range digital interf ace. The performance of the proposed circuit w as e v aluated using HSPICE with 1P , 5M, 3-wells, 0.18-m CMOS process (BSIM3v3.2 LEVEL53). As a result, sensiti vity of temperature sensor core is 0.783 mV/°C, with 0.89 % nonlinearity in -40 °C to 160 °C. This temperature sensor core has been f abricated using 0.6 m CMOS proces s. As a result of 10 dif ferent chips measurement is the a v erage sensiti vity of f abricated chip is 0.8343 mV/°C in 10 °C to 60 °C, with 2.70% nonlinearity . T emperature range of the sensor is then programmed to be 0 °C t o 100 °C using pulse width of V tg r and IJECE V ol. 8, No. 2, April 2018: 946 – 953 Evaluation Warning : The document was created with Spire.PDF for Python.
IJECE ISSN: 2088-8708 953 clock frequenc y of counter ( CP ). As the results of simulation, resolution of the sensor that its temperature range has been programmed is 0.392 °C with -0.98/+0.29 °C inaccurac y and total po wer consumption is 22.3 W in 25 °C. The future w ork of this research is designing mask layout of the propos ed digital interf ace, f abrication of whole circuit in one prototype chip and e v aluation of the characteristic. A CKNO WLEDGEMENT This w ork is supported by VLS I Design and Education Center (VDEC), the Uni v ersit y of T ok yo in collab- oration with Synopsys, Inc. and Cadence Design Systems, Inc. Refer ences [1] A. Goel, and G. Singh, ”A No v el Lo w Noise High Gain CMOS Instrumentation Amplifier for Biomedical Applications, ” International Journal of Electrical and Computer Engineering (IJECE), V ol. 3, No. 4, pp. 516- 523, Aug. 2013. [2] S. Meti, and V .G. Sang am, ”A Thorough Insight to T echniques for Performance Ev aluation in Biologi cal Sen- sors, ” International Journal of Electrical and Computer Engineering (IJECE), V ol. 6, No. 3, pp. 986-994, Jun. 2016. [3] X. Zhang, H. Zhang, G. Kang, P . Zhang, and H. Li, ”External Biomedical De vice Relaying Body Sensor Netw ork scheme, ” TELK OMNIKA, V ol. 11, No. 12, pp. 71027109, Dec. 2013. [4] M. A. P . Pertijs, A. Niederk on, X. Ma, B. McKillop, A. Bakk er , and J. H. Huijsing, ”A CMOS T emperature Sensor W ith a 3 Inaccurac y of 0.5 C From 50 C to 120 C, ” IEEE JOUN AL OF SOLID-ST A TE CIRCUITS, V ol. 40, No. 2, pp. 454460, Feb . 2005. [5] Z. K. La w , A. Bermak and H. C. Luong: ”A Sub-W Embedded CMOS T emperature Sensor for RFID F ood Monitoring Application”, IEEE Journal of Solid-State Circuits, V OL. 45, NO. 6, pp. 12461255, Jun. 2010. [6] R. Sakamoto, K. T anno, H. T amura and Zainul Abidin, ”A Sub-W , 1.0 V CMOS T emperature Sensor Circuit Insensiti v e to De vice P arameters, ” IEEE re gion 10 conference TENCON 2011, pp.626-629, No v . 2011. [7] P . C. Crepaldi, T . C. Pimenta, and R. L. Moreno, ”A CMOS lo w-v oltage lo w-po wer temperature sensor , ” Micro- electronics Journal, V ol. 41, No. 9, pp. 594600, June 2010. [8] J. Fujitsuka and K. T akakubo, ”A Consideration of T emperature Coef fi-cient on Gate-V oltage-Controlled PT A T V oltage Generator under Ultra Lo w Po wer Supply , ” Proc. of Electronics, Information and Systems Conference, Electronics, Information and Systems, I.E.E of Japan, GS11-2, pp. 14521457, Sep. 2010. [9] K. T anno, T . Mak oto, H. T amura, and O. Ishizuka, ”High-Performance CMOS T emperature Sens or Circuit, ” Note on Multiple-V alued logic in Japan, V ol. 32, No. 9, pp. 16, Sep. 2009. [10] T . Ohzone, T . Sadamoto, T . Morishita, K K omoku, T . Matsuda, and H. Iw ata, ”A CMOS T emperature Circuit, ” IEICE TRANS. ELECTR ON, V ol. E90-C, No. 4, pp. 895902, Apr . 2007. [11] M. T uthill, ”A Switched-Current, Switched-Capacitor T emperature Sensor in 0.6-m CMOS, ” IEEE JOUN AL OF SOLID-ST A TE CIRCUITS, V ol. 33, No. 7, pp. 11171122, Jul. 1998. [12] K. S. Szajda, C. G. Sodini, and H. F . Bo wman, ”A Lo w Noise, High Resolution Silicon T emperature Sensor , ” IEEE JOUN AL OF SOLID-ST A TE CIRCUITS, V ol. 31, No. 9, pp. 13081313, Sep. 1996. [13] H. Ik eda, K. T akakubo, and H. T akakubo, ”Drain Current Zero-T emperature-Coef ficient Point for CMOS T emperature-V oltage Con v erter Operating in Strong In v ersion, ” IEICE TRANS. FUND AMENT ALS, V ol. E87- A, No. 2, pp. 370375, Feb . 2004. [14] A. Setiab udi, R. Sakamoto, H. T amura and K. T anno, ”A Lo w-V oltage and Lo w-Po wer CMOS T emperature Sensor Circuit with Digital Output for W ireless Healthcare Monitoring System, ” 2016 IEEE 46th International Symposium on Multiple-V alued Logic (ISMVL), Sapporo, pp. 183-188, 2016. [15] R. Sakamoto, K. T anno, H. T amura, ”A Lo w-Po wer and High-Linear Current to T ime Con v erter for W ireless Sensor Netw orks, ” IEICE TRANSA CTIONS on Fundamentals of Electronics, Communications and Computer Sciences, V ol.E95-A No.6 pp.1088-1090, 2012. [16] K. Ueno, T . Asai and Y . Amemiya, ”Lo w-po wer temperature-to-frequenc y con v erter consisting of subthreshold CMOS circuits for inte grated smart temperature sensors, ” Else vier Sensor and Actuators A: Ph ysical, V ol. 165, Issue. 1, pp. 132-137, Jan 2011. [17] P . Chen, C. C. Chen, C. C. Tsai and W . F . Lu, ”A T ime-to-Digital-Con v erter -Based CMOS Smart T emperature Sensor , ” IEEE J. Solid-State Circuits, V ol. 40, No. 8, pp. 1642-1648, Aug. 2005. [18] M. Sasaki, M. Ik eda and K. Asada, ”A T emperature Sensor with an Inaccurac y of -1/+0.8 C using 90-nm 1-V CMOS for Online Thermal Monitoring of VLSI Circuits, ” IEEE T ra n s . Semiconductor Manuf acturing, V ol. 21, No. 2, pp. 201-208, May 2008. CMOS T emper atur e Sensor with Pr o gr ammable T emper atur e Rang e for Biomedical ... (Agung Setiab udi) Evaluation Warning : The document was created with Spire.PDF for Python.