一种新型的集成电路片上CMOS 温度传感器外文翻译

1、A Novel Built- in CMOS Temperature Sen sor for VLSICircuitsWang Nailong, Zhang Sheng and Zhou Runde( Institu te of M icroelectronics, T sing hua U niversity , B eij ing 100084, Ch ina)Abstract: A novel temperature sensor is developed and presented especially for the purpose of online the rmalmoni to

2、 ring of VLSI chips. This sensor requires very small silicon area and low power consumption, and the simulation results show that its accuracy is in the o rder of 018. The proposed sensor can be easily implemented using regular CMOS process techno logies, and can be easily integrated to any VLS I ci

3、rcuits to increase their reliability.Key words: temperature sensor; thermal testability; frequency output.EEACC: 1265A; 2560; 2570DCLC number: TN 47Document code: A Article ID: 025324177 (2004) 03202522051IntroductionDue to the advances in the fabricaion process field of in tegrated circu its, the c

4、omponent den sityand the overall power dissipat ion of the high per fo rmance VLSI chips increase cont inuously. At the beginning of this century, the power dissipated in asingle ch ip has exceeded 100W , and tightly packed chip assemblies as the multichip modules can even dissipate thou sandswatts.

5、 Therefore, the thermalstate of integrated circu its has been always a great prob lem concerned and is considered as a bottle neck in increasing the in tegrat ion of elect ron ic system s.To overcome this problem , many researchers developed low 2power design techn iques for VLS Isystems. In order t

6、o avoid thermal damages,continuous thermal monitoring should be appliedduring both the production reliability testing and the field operation. An eff icient way is to buildtemperatu resensors in to all VLSI chips, with theapp ropriate circuitry p roviding easy readout. Insome earlier works , the res

7、earchers used theparasitic, lateral or sub strate bipolartran sistors,which can be realized in mo st of the CMOS processes, as thermal sen so rs. These are u sually PTAT sensors. The weakness of these senors is that the bipolar structu resare not well characterized in a MOS process. Thus, although t

8、hey canp rovide a sat isf iect solution for a given process, thecircu its can not be regarded as a general CMOS approach and can not be widely used.2Problem formulationThere are various temperature sensors suitable for the rmalstate verification of in tegrated circuit microstructures such as the rmo

9、resistors, pnjunctions, and the exploitation of the weakinversion of MOS transistors. Our objective is to convert the temperature to an oscillat ing signal to make it compat ib le to digital circu it design method and facilitate the evaluat ion of the temperature sensed. A temperatu re sen so r base

10、d on a ringo scillator is introduced in Ref., this cell guarantees a accuracy of 3 that is marginally accep table as a chiptem perature sensor but the silicon area required is rather big. AMOS temperature controlled oscilla to risused as asensor to monitor the thermal state of microelectronic struct

11、u res in Ref. How ever, this sensor requires about 10 to 15mW power to drive the thermal delay line and the dissipatertran sistor.To overcome these inconven iences, w e th inkthat the temperature sensors to be used as builtinun its for VLSI circuits online the rmalmoni to ring should meet some speci

12、al requirements as follows:( 1 ) Nearly linearity in a temperatu rerange(usually 0 100) ;( 2 ) Low power consumption (no more than 1 mW ) ;( 3 ) Simple structure and small silicon area(usually no more than 40 transistors) ;( 4 ) Easy read out results with favorably digital output signal (e. g. , the

13、 frequency of asquare wave which carries the temperature information) ;( 5 ) Easy (one point) calib rat ion;( 6 ) High accu racy ( in the order of 2 or less) ;( 7 ) Compat ib ility w ith the p resen t CMO Sp rocess;Con sidering the given requ irements, we present a new builtin temperatu resensor mee

14、ting all the above requirements3 Built- in thermal mon itor ing sensorOur new temperature sensoris a voltage controlled relaxation o scillato rbasedtemperature sensor shown in Fig. 1. The circuit consists of two parts, a voltageout put sensor and a relaxation oscillator.F ig. 1 Temperature sensor de

15、signed based on a voltage2cont ro lled relaxation oscillator 3.1Voltage-output sen sorOur voltage output sensor circuit exploits the temperature dependence of the mosimportant parameter of the MOS transistor, namely, the thresh old voltage (V T ). The thresh old voltage has a negative temperature co

16、eff icient as:V T (T ) = V T (T 0) + a (T - T 0) (1)where a is the temperature coeff icient with atypical value of - 118mVöK in CMOS 0135Lm 5V technology; V T (T 0 ) is the value of the th reshold voltage at temperatu re T0.As shown in Fig. 1, the voltage output sensor is a th reshold voltage r

17、eference cell. The pchannelt ransistors P1, P2 constitu teacurrent mirror. The current of transist or N1 is mirrored to tansistors N 2,N 3, and N 4. The vo ltage drop on these t ran sistors isfed back to the gate of N 1. Fo r easy calculat ing,we choose asame size of the transistors N 2,N 3, and N 4

18、 (BN 2= BN 3= BN 4) , and we choose approp riatesize of the other transistors to ensure that the transisto rs P1, P2, N 1, N 2, N 3, and N4 are all in the state of saturation. Then the out put voltages of th is sen so r are in direct proportion to the thresh old voltage and linear with temperature a

19、nd their values are:V H = V T (1 +2KP12KP12 - 3KN 12) = k1V T (2)V L = V T (1 +2KN 12KP12 - 3KN 12) = k2V T (3)where is determined by the ratio between the gatesizes of the nchannel t ran sistor N 1 and N 2, and is the ratio of the gate sizes of the pchannel transistor P1 and P2.By adju st ing the s

20、izes of the t ran sisto rs, w efound shou ld be b igger than threetimes of,when the transistors P1, P2, N 1, N 2, N 3, and N 4 are all in the state of saturat ion.The advantages of th is circuit arrangeme t arethe simplicity and the stable outpu t. A n important feature is that the output voltages o

21、f V H and V L arepractically independen t of the supply voltage (V DD ). 3. 2Voltage-con trolled relaxa t ion osc illa torThe quick in terfacing of the analogue, current output sensor with the digital environmen t is not asimple task. To overcome this problem we usea voltage controlled relaxat ion o

22、scillato r as the voltage frequency converter. The output signal of th isconverter is asquare w ave, the frequency of which carries the temperatu re info rmation. This frequency can be easily turned in to adigital number bycoun ting the square wave pulses in a prescribedt ime window.As shown in F ig

23、. 1, the curren t of the resisto rism irro red using thet ran sisto rs P3, P4, P5,N5,N6 to provide the same sou rce and sink current s to charge and discharge thecapacitor C. Assum ing thein it ial value of the f o sc is logic 0, then the t ran sistor P6 is on and the t ran sisto rN 7 is off cau sin

24、g the capacitor C to be charged using the source curren t Iun t il V cexceeds the upper th resho ld V H. W hen th isoccu rs, the output latchtoggles and the logic valueof f o sc becomes logic 1, w hich in turn makes thet ran sistor P6 off and the tran sistor N 7 on. Th ismakes the capacitor C to be

25、discharged by the sinkcu rren t until the capacit r voltage falls below alowerthreshold V L at w h ich t ime the en t ire cyclerepeats. N eglecting the delay of the comparators,latch and transistors P6 and N 7, the oscillation cycle time should be:As the current is small and the W öL rat io of

26、the transistor P3 is chosen to be big in this design,the V gsp can be appro ximated to the th reshold voltage of the transistor P1 and therefo e the currentcan be approximated byAnd the temperature dependence of the resistor Rs is where k is the temperatu re coeficien t of the resistor,with typical

27、value k= 255×10- 6ö fo r polysilicon sheet resistor in the CMOS 0135Lm 5V technology.Therefore, the oscillation cycle time is foundto beThis equation implies that the cycle t ime ofthe relaxation oscillator is nearly linear with temperature, and then the f requency of the o scillator is4Si

28、mulation results and discuss ionThe simulation result of the voltage output the rmalsen sorisillustrated in F ig. 2, and the varia ion of the relaxat ion oscillator based sensor oscillation cycle t ime and f requency versus the ch iptemperatu re is shown in Fig. 3.To evaluate a buildin thermal senso

29、r, thereare three important characterist ics: accu racy, sili2con area ( transistor number ) , and power dissipation. The characterist ics of our voltage cont rolled relaxation oscillator based sensor is shown in Table 1:5ConclusionIn this paper, apractical and efficient built intemperatu resensor f

30、or the rmalmonito ring of the integrated circuits is in troduced. The main advantages of the presented chip temperature sensors are low silicon area, low power dissipation, digital output inform of oscillation frequency, high accuracy,and easily implemented using regular CMOS process techno logies.

31、Therefore, this sensor can beeasily in tegrated to any VLS I circu it s to increasecircu it sreliab ility.References 1 Chandrakasan A , ShengS, Broderson R. Low 2power CMOS digital design. IEEE J So lid2State Circuits, 1992, 27 (4) : 473 2 NebelW , Mermet J. Low power design in deep subm icronelectr

32、onics. Boston: Kluwer A cadem ic Publishers, 1997,Chap ter 4. 1 3 Montane E,Bo ta S A , Sam itier J. A compact temperature sen2so r of a 110Lm CMOStechno logy using lateral PN P transis to rs. In: P roc THERM IN IC96Wo rk shop, 1996: 45 4 Bianch i R A , Karam J M , Courto is B. CMOS compatible tem2p

33、erature senso r based on the lateral bipo lar transisto r fo rvery w ide temperature range app lications. Senso rs andA ctua2to rs A: Physical, 1998, 71 (1ö2) : 3 5 Quenot G M , Paris N. A temperature and voltage measurement cell for VLSI circuits. In: Euro2A sic91, 1991: 334 6 SzekelyV , Rencz

34、M. Thermal test andmonito ring. Proceeding of the European Design and Test Conference, 1995: 601 7 A rabi K, Kam inska B. Built2in temperature senso rs fo r online thermal monito ringof m icroelectronic structures. IEEEInternational Conference on Computer Design, 1997: 8 BoschB. A thermal o scillato

35、 rusing the thermoelectronic ( seeback) effect in silicon. Solid2State Electron, 1976, 12: 372 9 Szekely V ,M arta C, Kohari Z, etal. CMOS sensors for online thermal monito ring of VL S I circuits. IEEE T rans VLSISyst, 1997, 5 (3) : 270 10 Huang Yip ing, Zhu Shiyang, LiAizhen, et al. High temperatu

36、re pressure sensor fabricated with smartcut SO Imaterials.Chinese Journal of Sem iconductors, 2001, 22 (7) : 924 ( in Chinese)一种新型的集成电路片上CMOS 温度传感器王乃龙 张盛 周润德(清华大学微电子学研究所, 北京 100084)摘要: 介绍了一种可以用于片上温度监控的CMO S 温度传感器, 该传感器具有面积小、功耗低、精度高、易于实现等优点, 可以比拟容易地集成到芯片上实现温度监测功能.关键词: 温度传感器; 热可测性; 频率输出EEACC: 1265A; 2

37、560; 2570D中图分类号: TN 47 文献标识码: A 文章编号: 025324177 (2004) 03202522051 引言由于集成电路制造工艺领域的先进性，该组件密度和高表现所整体功耗超大规模集成电路芯片不断增加。在本世纪开始，电力消耗一个单一芯片的电力消耗已经超过100瓦，而紧凑的多芯片模块，甚至可以驱动数千瓦的芯片集。因此，在集成电路中的热态一直都是一个受到最大关注的问题，同时也成为了提高电子系统的集成度的一个瓶颈。为了克服这个问题，许多研究人员在超大规模集成电路系统开发了低功耗设计技术。为了防止热损失，在可靠性试验和实地操作过程中应用持续热监测。一种有效的方法是在所有大规

38、模集成电路芯片中应用温度传感器，同时为适当的电路提供便利的读出。在一些早期的工作中，研究人员使用的寄生，横向或衬底双极晶体管，它可以在CMOS中最进程，实现热传感器。这些通常是正比绝对温度传感器。这些传感器的弱点是，在才cMOS工艺中两极结构特点不是很好。所以，虽然他们可以为一个给定进程提供一个满意的解决方案，但这种电路不能被视为一般的CMOS方案，因而不能被广泛使用。2 问题陈述现在有适合各种温度传感器集成电路微结构的热态验证，如能热电阻，pn结路口，以及弱反转开发的CMOS晶体管。我们的目标是要转换温度的振荡信号，使其兼容数字电路设计方法，促进温度效应评估。在文献5介绍了一个基于环形振荡器

39、温度传感器，这个细胞是轻微的温度传感器芯片，保证了精确的3，但芯片面积需要相当大。在文献6中介绍了温度控制的CMOS振荡器，它作为一个传感器来监测微观电子结构的热状态。不过，为了驱动热延时线和消能晶体管该传感器大约需要10至15毫瓦的能量。为了克服这些不便，我们认为，温度传感器被用来作为内置的VLSI电路在线热监测单位要满足一些如下的特殊要求：为了克服这些不便，我们认为，温度传感器被用来作为内置的VLSI电路在线热监测单位要满足一些特殊要求，遵循如下：1在近线性的温度范围内通常为0100;2低功耗不超过1毫瓦;3结构简单，芯片面积小通常不超过40个晶体管;4容易读出的结果与毫不逊色数字输出信号

40、例如，一个方波的频率进行温度信 息;5易1点校准;6高准确度在命令2或以下;7本CMOS工艺兼容性; 考虑到给定的要求，我们提出一个新的内置温度传感器满足所有上述要求。3. 内置热监测传感器我们的新的温度传感器是一个电压为本位弛张振荡器的温度传感器在图1所示。该电路由两局部组成，电压输出传感器和一个放松操作系统振荡器。图1一种基于电压控制轻松振荡器设计的温度感应器我们的电压输出传感器电路利用的温度参数取决与最重要的CMOS晶体管温度参数，也就是说，阈值电压VT。阈值电压有一个负温度为V T (T ) = V T (T 0) + a (T - T 0) (1) 其中A是一个典型的温度系数值-在中

41、电压为5V时为1.8mV / K，V T (T 0 )是在温度T0的阈值电压值。正如图1所示，传感器输出电压的阈值电压作为参考单元。它的p结通道由晶体管的P1，P2构成了电流。该晶体管N1的晶体管电流镜像到N2，N3，和N 4。对这些晶体管的压降反应到了N1门。为了便于计算，我们选择了同样大小的晶体管N 2,N 3, and N 4 (BN 2= BN 3= BN 4) ,我们选择其他适当大小的晶体管，以确保该晶体管的P1，P2， N1，N2，N3，和N 4是都在饱和的状态。然后，该传感器的输出电压成正比，电压和阈值随温度线性和它们的值是V H = V T (1 +2KP12/KP12 - 3

42、KN 12) = k1V T (2)V L = V T (1 +2KN 12/KP12 - 3KN 12) = k2V T (3)其中KP 12取决于N沟道晶体管N1的和N 2门大小的比例，KP12取决于p沟道晶体管的栅极体积比P1和P2。当晶体管的P1，P2，N1，N2，N3和N 4在饱和状态时，通过调整晶体管的大小，我们发现应大于3 倍。 该电路安装的好处是简单和稳定的输出。一个重要特点是，输出电压的VH和VL几乎与电源电压独立。 3.2 压控轻松振荡器该模拟接口快，在数字环境传感器电流输出不是一个简单的任务。为了克服这个问题，我们使用电压频率转换器的电压控制轻松振荡器。这个转换器的输出信

43、号是方波，其中在频率中带有温度信息。通过计算在规定的时间窗口的方波脉冲，这个频率可以很容易地变成数字量。正如图1所示，电阻器的电流镜像使用晶体管P3，P4，P5，N5，N6，提供相同的源和汇电流来支持电容C的充电和放电的。假设f o sc初始值为逻辑0，那么就和晶体管P6是接通的，晶体管P7是关闭，造成的电容C放电，以至于使源电流I直到Vc值超过最高限额的VH。当发生这种情况，输出锁存器切换和fosc逻辑值变成逻辑1，这反过来可以使晶体管P6关闭和晶体管N7接通。这使得电容C就出现放电，直到电容电压下降到低于下限VL的，届时整个周期重复。忽略了比拟器的延迟，闭锁和晶体管P6及N 7，振荡周期应

44、该是：T o sc =2C (V H - V L )/I=2C (k 1 - k2)V T/I (6)给出的电流I= (V DD - V gsp3)/Rs (7)在这个设计中，由于电流小，而晶体管p3的W / L比拟大，V gsp3可以近似为晶体管的阈值电压P1，因此电流可以近似I = (V DD - V T )/Rs (8)而最大的温度依赖电阻RsR s (T ) = R s (T 0) (1 + k T ) (9) 其中k是电阻器在微米5伏技术CMOS多晶体硅的温度系数典型值K =255×/。因此，可以发现振荡周期这个方程意味着放宽振荡器的周期时间几乎与温度线性，那么振荡器频率f

45、 o sc1/1 + BT (11)4 仿真结果和讨论该温度传感器电压输出如图2所示，同时振荡器的传感器振荡周期时间和频率与芯片温度的变化如图3所示的仿真结果。图2 电压输出传感器的输出电压与温度的关系图电压输出传感器图3 放宽振动器传感器振荡频率和振荡周期时间评价一个内置的热传感器，有三个重要特性：准确性，芯片面积晶体管数量和功耗。电压控制振荡器松弛基于传感器的特性见表1表1 已开发的温度传感器的温度特征特性值准确度0. 8晶体管数目34功耗标准频率兆赫5 结论在这篇文章中,提出了一种实用，高效内置的集成电路热监测温度传感器。所提出的温度传感器芯片的主要优点是低硅面积，功耗低，振荡频率数字外置，高准确度的形式，并轻松实现使用常规CMOS工艺技术。因此，该传感器可以很容易地集成到任何VLSI电路,从而提高集成电路的可靠性。参考文献 1 Chandrakasan A , Sheng S, Broderson R. Low -power CMOS digital design. IEEE J So l