第29卷 第7期2008年7月

半 导 体 学 报

JOU R N A L O F SEM ICO N D U CT OR S

Vo l.29 No.7

July,2008

*Project supp orted by the National Natur al Science Foundation of China (No.60475018)an d th e B eijing M unicip al Science &Tech nology Develop -m ent Pr ogram (No.D0305004040221-2-05) C orresponding author.E mail:xin gxp1983@http://www.doczj.com/doc/5e46a17602768e9951e73854.html

Received 5January 2008,r evis ed manuscrip t received 23M arch 2008 2008C hin ese Institute of Electronics

A Novel CMOS Current Mode Bandgap Reference *

Xing Xinpeng

1,

,Li Dongm ei 2,and Wang Zhihua

1

(1Institute of M ic roele ctronics ,T sing hua Univ e rsity ,B eij ing 100084,China)

(2Dep artment of Electronic En gineer ing ,T singhu a Univ er sity ,Beij ing 100084,Ch ina )

Abstract:A no vel CM O S bandg ap re fer ence is pr ese nte d.T he output r efe rence o f th is new c ur rent mo de str ucture ca n be set to an ar bitr ar y v alue abov e the bandg ap vo ltag e o f silicon,avo iding of fse t in application.It also o ve rco mes the system -a tic m ism atch o f co nventional curr ent mode bandg ap r efe rences.T he pr o po sed bandga p r efer ence has bee n im plemente d in U M C 0 18 m mixed mode techno lo gy.U nder the supply v oltage of 1 6V ,the pro posed bandgap r efer ence pr ov ides an output r efe rence of 1 45V and consumes 27 A o f supply curr ent.U sing no curv ature co mpensation,it can r each a temper -a tur e co eff icient o f 23ppm / f ro m 30to 150 w ith a line r egula tio n of 2 1mV /V fr om 1 6to 3V and a PSR R of 40dB at D C fr equency.T he chip are a of the bandgap r efer ence (without pad)is 0 088mm 2.Key words:CM O S;bandg ap re fer ence;cur rent m ode EEAC C:1290

C LC number:T N432 Document code:A A rticle ID:0253-4177(2008)07-1249-05

1 Introduction

H ig h quality bandgap reference providing voltage or current independent of supply vo ltag e and tem pera -ture is in great demand in analog and mix ed mo de inte -g rated cir cuits design,such as data converters and DC -DC pow er conver ters.

Lo w supply vo ltag e and high precision are tw o de -sign trends for CM OS bandg ap reference.To reduce the supply vo ltag e,Jiang and Lee [1]used an operational tr ans -impedance amplifier to replace the operational tr ans -co nductance am plifier in the bandgap reference.Banba,Leung ,and Ker et al .[2~4]presented three dif -ferent curr ent mode structures which transform the ad -dition of tw o v oltages to an additio n o f tw o currents.Ano ther advantage o f these current m ode bandg ap ref -erences is that the o utput r efer ences can be adjusted to the proper value.To improve the pr ecision,several hig h order cur vature co mpensations are introduced.Le -ung et al .[5]

developed a seco nd -o rder curvature com -pensation using r esistors w ith opposing tem perature coefficients.Audy [6]further pr opo sed a third order cur -v ature compensation based o n ser ies and parallel com -binations of tw o kinds of resisto rs.M alcov ati et al .[7]pro posed a new metho d,w hich generates a no n -linear current to compensate the non -linear V EB of BJT.

For conventional bandgap reference,the o utput reference is a fix ed value aro und 1 24V.In application,an o peratio nal amplifier (OPA )w ith vo ltag e -voltage

feedback is needed to am plify or attenuate the 1 24V

bandgap voltage to the desir ed v oltage reference.Be -cause o f the o ffset of CM OS OPA,altho ug h the bandgap reference is stable w ith tem perature,the sta -bility o f the desired vo ltag e r eference is no t very go od.

Curr ent mode bandg ap r efer ences w ith ar bitrary output references can so lve this problem [2~4].H ow ev -er ,in these three current mode bandgap r eferences,sy s -tematic m ismatch is unav oidable,w hich w ill constrain the precisio n.

Althoug h lo w supply v oltage is a popular design,high supply v oltage is also com m on in som e high pre -cisio n desig ns.Lo w supply vo ltag e is no t our goal in this w ork.T he presented bandg ap reference focuses on avo iding offset introduced by O PA in application and preventing system atic mismatch.T he silico n ver-i

fication in U M C 0 18 m m ixed mo de technolog y sho w s that under 1 6V vo ltag e,the proposed bandg ap reference can supply an ar bitrary output refer -ence above 1 24V (1 45V is adopted here as an ex am -ple)w ith a temperature co efficient of 23ppm/ fr om 30to 150 .

2 Conventional bandgap references and

their disadvantages

2.1 Conventional bandgap references with fixed output

references and their disadvantages A ty pical co nv entio nal CMOS bandg ap reference