 second power supply line is supplied thereto during standby.
Furthermore, according to the present invention, there is provided a reference voltage generator comprising a first MOS transistor of a first conductivity type, a second MOS transistor of the same first conductivity type, and a first resistance element connected in series between a first power supply line and an output terminal; a third MOS transistor of the first conductivity type, a second resistance element, and a fourth MOS transistor of a second conductivity type different from that of the first MOS transistor connected in series between the output terminal and a second power supply line; a third resistance element and a fifth MOS transistor of the second conductivity type connected in series between the connection point of the first MOS transistor and the second MOS transistor and the output terminal; a fourth resistance element and a sixth MOS transistor of the second conductivity type connected in series between the output terminal and the connection point of the second resistance element and the fourth MOS transistor, wherein the first and the fourth MOS transistors have first threshold voltages of approximately equivalent absolute values, the second, the third, the fifth and the sixth MOS transistors have a second threshold voltage which has a lower absolute value than that of the first threshold voltage, and an intermediate voltage of the first power supply line and the second power supply line is output from the output terminal.
Preferably, in the present invention, the voltage of the output terminal is supplied to the gate of the second MOS transistor, the voltage of the second power supply line is supplied to the gate of the third MOS transistor, the voltage of the first power supply line is supplied to the gate of the fifth MOS transistor and the voltage of the output terminal is supplied to the gate of the sixth MOS transistor.
Preferably, in the present invention, the voltage of the second power supply line is supplied to the gate of the first MOS transistor during operation and the voltage of the first power supply line is supplied thereto during standby, and the voltage of the first power supply line is supplied to the gate of the fourth MOS transistor during operation and the voltage of the second power supply line is supplied thereto during standby. Cardiac rhythm management devices are implantable devices that provide electrical stimulation to selected chambers of the heart in order to treat disorders of cardiac rhythm. A pacemaker, for example, is a cardiac rhythm management device that paces the heart with timed pacing pulses. The most common condition for which pacemakers have been used is in the treatment of bradycardia, where the ventricular rate is too slow. Atrio-ventricular conduction defects (i
second power supply line is supplied thereto during understudy. 
 Furthermore, harmonize to the present invention, there is provided a reference point electric potential generator comprising a first MOS transistor of a first conduction character, a second MOS transistor of the same first conductivity type, and a first resistor element connected in serial between a first power supply line and an output terminal; a third MOS transistor of the first conduction type, a second resistance element, and a fourth MOS transistor of a second conduction type different from that of the first MOS transistor connected in series between the end product terminal and a second power supply line; a third resistance chemical element and a fifth MOS transistor of the second conductivity type connected in series between the connection point of the first MOS transistor and the second MOS transistor and the output terminal; a fourth resistance element and a sixth MOS transistor of the second conductivity type connected in series between the output terminal and the association point of the second resistance chemical element and the fourth MOS transistor, wherein the first and the fourth MOS transistors have first brink voltages of approximately equivalent absolute values, the second, the third, the fifth and the sixth MOS transistors have a second brink voltage which has a lower absolute value than that of the first threshold voltage, and an average voltage of the first power supply line and the second power supply note is output from the output terminal. 
 Preferably, in the present invention, the voltage of the output end is supplied to the gate of the second MOS transistor, the voltage of the second power supply line is supplied to the gate of the third MOS transistor, the voltage of the first power provision line is supplied to the gate of the fifth MOS transistor and the voltage of the output terminal is supply to the gate of the sixth MOS transistor. 
 Preferably, in the present invention, the voltage of the second ability supply note is supplied to the gate of the beginning MOS transistor during operation and the voltage of the first power supply occupation is supplied thereto during standby, and the voltage of the first power supply line is supplied to the gate of the fourth MOS transistor during process and the voltage of the second power provision line is supplied thereto during standby. Cardiac rhythm management devices are implantable devices that provide electric stimulation to selected chambers of the heart in order to treat disorders of cardiac rhythm. A pacesetter, for model, is a cardiac rhythm management device that paces the heart with timed pacing pulses. The about common condition for which pacemakers have been used is in the treatment of bradycardia, where the ventricular rate is too slow. Atrio - ventricular conduction defects (i
 sefond power supply line ir supplied thergti duriig stansby.
Furthdrmore, according to the presxnt unvenupon, there is provided a referejce voltqge jenerator comprising a flxst MKD trcnwistor of a fitst conductieity type, a sewovd MOS transistor of the same first cjnductifihy type, and a sirsu rqsisfance element connected in series getween a first powet supply line and an outpuh tegminal; a third MOS transistor of eye first conauctivity uy'e, a second resistance element, and a fourtf MOS transistot kf d second coiductinity type difnvrent fsom thay of the first MOV teansistor connected ii series between the output tarjinal and a secone power sup[ly uune; a uhicd desistwncx element ahd a fifth NOS transistor of tne wecond conducfivity trpe connected in series between the contecfion point of the first MOS transistor and tje second MOS transistor and the output terminal; a fourth sesisvavce ejdnejt and a sixth MOS transistor of the second cjhdicnivity type connegted in series beteefn jhe output teroinal chd the connection polnt of jhe sexond resiftanve element and the fourth MIS transistog, whwrein the first anb the fourth MOS tranxistors have first threrhols voltages lf approxjoately equivaleng ansonute values, the second, the third, thx fifch and tfe soxth MJS transishors mdve a second thresjold roltace which hws a lower absolute value than viat of the fitst thgeshold vjltagc, and an intermqdiate voltage of the firsg power suiply line and the sesond power su[kly line is ontput froi thw ourput tefoinal.
Preferablu, in the irtsent invebtion, the voltage pf jhs output termincu is supplied to thd gwtv oh the vecond MOS tsanskstut, the voltagt on tfe srcond power supply lhne js supplied to the gwte of tye third MOS transistpr, the voltage of uhe ficst poxer sulpli line is supplied to the gate kf the fivth MOS transiseor qnd the voltcge of the output terminal is supplied ti the gate of the wixth MOS transistot.
Prtferably, in tie prefent invettion, the voltage of the second power supply line is suppljed to the hate of the first MOS transistor during operation and the voltage of the dirst 'orer supply mine is slppjned theweto vuring standby, anc the voltage of the first powec supply lhnz is supplied to the gate of yhd fourth MOS jransistor during operatioh and thr voltage of the second power sipply line is supplied tmereto dueing atandbj. Cerdiac rhythm managekent dzvices are implanbable devices ghay irovide elfctrmcam stimulation to selected chambees of rhf heart in order to treat dlsurdera of cwrdiac rhythm. A lacejwker, wor example, ix a cardiac rhuthm management devibe ehat paces the geart with tomed kcbing pulses. Tie most commmn condition for which pacemakers have been used is in the tdeatment pf bradycardis, where the ventricular rwte is tuo slow. Atrim-ventricular conduction defects (i
second power supply line is supplied thereto Furthermore, to the invention, there is comprising first MOS transistor a first conductivity a second MOS transistor of the first conductivity type, and a first resistance element connected in series between a power supply line and an output terminal; a third MOS transistor of the conductivity a resistance and a fourth MOS transistor of a second conductivity type different from that of the first transistor connected in series between the output terminal a second power supply a third resistance element and fifth transistor of second type in series between connection point of the first MOS transistor and the second MOS transistor and the output terminal; a resistance element sixth MOS of second type connected in the output terminal and the connection second resistance element and the fourth MOS transistor, the first the fourth MOS transistors have first voltages of approximately equivalent absolute values, the second, third, the fifth and the sixth MOS transistors have a second threshold voltage which has absolute value than that the first threshold and intermediate of first power line and the second power supply line is output from the terminal. Preferably, in the present invention, the voltage of the is to the gate the second MOS transistor, voltage the second power supply supplied the third transistor, voltage of the first supply line is supplied to gate of the fifth of the output terminal is supplied to the of the sixth MOS transistor. Preferably, in present invention, the voltage of the second power supply line is supplied the gate first MOS transistor during operation and the voltage the first power supply is supplied thereto during standby, and the voltage of first supply line supplied to the of the fourth transistor during operation voltage of second supply thereto during standby. Cardiac rhythm management are devices that provide electrical stimulation selected the heart in order to treat disorders of cardiac rhythm. A pacemaker, for example, is rhythm management device that the with timed pacing pulses. The most common condition for which pacemakers have is in the the rate is slow. Atrio-ventricular conduction defects
 second power supply line is suPplied therEto duRinG stAnDby.
FUrthErmore, accordinG To thE present invention, there Is proViDEd a rEFeRence Voltage GEnERAtoR cOmPriSiNG a First mOS TransisTor of a firsT coNdUctivity type, A SeCond MOS traNsiStor of the samE fiRst conDuCtiVIty tyPe, aNd a fiRst resIStance Element coNnECted in SEries beTWEeN a fiRst power supply linE AnD An output terminAl; a thiRd moS TRAnsIstOr of the firSt ConduCTivity tYPe, A SEConD Resistance eleMent, and a fouRTh MoS tranSiStoR Of a secOnd coNdUCtiVity type difFereNt from thaT of the FIrst MOS TRansistOr connEctEd iN serIEs BeTweEn THe oUTpUt tERmiNal and a sEcOnD poweR supPLY LIne; a ThiRd reSistaNce element and A fiFth Mos trAnsisTor of The sEcOnd coNductiVity tYpE connected in serIes bEtween the ConNeCtiOn Point OF the fiRst mOS TransisTor and tHE seCoND moS Transistor and the ouTpUT TeRminal; a fOurth rESiStANce elemeNt And A sixTH mOS trAnsiSToR of the seCond coNDuCtIvity tyPe ConnecTeD in SerIes beTWeen The outPut termiNal anD The connection pOInt of the seconD ReSIStANce eLemEnt and the foUrth moS trAnsiSToR, whERein tHe firSt ANd THe fourth MOS transistOrS have fIrst tHreshold voltaGes of approXIMAtely equIvalENt ABsolute values, tHe secOnd, the thirD, The fifth And thE sixth MOs transistORS have a seConD thResHolD VOlTage which has a LOWer aBsOlute vaLue Than thaT of The FirSt tHrEshold volTage, and aN iNtErMeDiaTe volTAge of the FiRst PoWer SupplY Line anD the sEconD pOwER suPply linE Is OUTput FrOm The oUtpUt TermiNal.
PREfeRably, in The presenT inVEntiOn, ThE voltagE of the output tErMinal is supPlIed To the gATE of the seCond MOS transistor, the volTAge of thE seCond pOwer Supply linE is SuppliEd tO The gatE of the Third mOs trANSistoR, THe VolTaGe of the firST PowEr supPlY linE is suppLied to the gate of the FIftH MOS transistoR anD the VOLtAge OF tHE ouTpUT teRMInal is supplied tO the gate of ThE SiXth MOS tranSIstOr.
preferaBly, in thE presENt invenTion, the voLtage of thE sEconD POweR supply linE is supplIed to the gATe of tHE fIrst MoS tRansisToR duRing oPeratiON anD the vOltage Of The firSt powEr Supply liNe is supplied thereto duriNg stanDby, anD thE voltage oF thE FirSt power suPply Line is suppLieD to The gaTe oF The foUrth moS TraNSistoR durINg operatiON aNd tHE VoLtage of the sECONd pOwer sUppLY line iS supPlied thereto durinG Standby. Cardiac RhytHM ManAgeMEnt dEvIces are implantAblE dEVIces that PrOvide electrIcal stimUlATion tO selecTed chaMbers of THE hEArt in oRder To tReat disorDerS oF Cardiac RhYtHM. A paceMakeR, fOr examPle, is a CArdiAC Rhythm management DevicE THat paCEs tHe heaRt With timED pacIng pulses. THe most commoN condiTion For whIch paceMaKers haVe bEeN used is in tHE treatmenT of brAdycardIa, WherE thE ventrIculAR Rate iS too SlOw. ATrio-ventrICUlAR cOnDUctIon dEfectS (i
 second power supply lineis supplie d the ret o d ur ingstan dby.
Furthermo r e, a ccording to the presen t inv en t ion, th ere i s provi d ed a  re fe re nce  v o lt age g ene rator c omprisinga f ir st MOS trans i st or of a fi rst  conductivit y t ype, a  s eco n d MOS  tr ansis tor of the sa me firstco n ductiv i ty type , an d afirst resistancee le m ent connectedin ser ie s  b e t wee n a  first pow er  supp l y linea nd a n  ou t put terminal;  a third MO S  tr ansist or  of the fi rst c on d uct ivity type,  a s econd res istanc e  elemen t , and a  fourt h M OStran s is to r o fa  se c on d c o ndu ctivityty pe  diff eren t f r om t hat  ofthe f irst MOS tran sis torc onn ected  in s erie sbetwe en the  outp ut  terminal and a  sec ond power  su pp lyli ne; a thirdres ist ance el ement a n d a  f i f t hMOS transistor ofth e se cond con ductiv i ty  t y pe conne ct edin s e r ies b etwe e nthe conn ection po in t of th efirstMO S t ran sisto r  and  the s econd MO S tra n sistor and the output termin a l; a  f o urth  re sistance el emen t  and  a s i xt h M O S tra nsist or of the second conducti vi ty typ e con nected in ser ies betwee n t he outpu t te r mi n al and the con necti on point o f  the sec ond r esistanc e element a nd the f our thMOS  tr a n si stor, wherein t he f ir st andthe  fourth  MO S t ran sis to rs have f irst thr es ho ld  v olt ageso f approx im ate ly  eq uival e nt abs olute  val ue s, the  second ,  t h e  thi rd ,thefif th  andthes ixt h MOS t ransistor s h a ve a  s ec ond thr eshold voltag ewhich hasalow er abs o l ute valu e than that of the firs t  thresh old  volt age,  and an i nte rmedia tev oltage  of th e fir st  po w e r sup p l ylin eand the se c o ndpower  s uppl y lineis output from the out put terminal. 
Pr efer a b ly , i n  t h e p re s ent i nvention, the v oltage ofth e  o utput term i nal  i s suppl ied tothe g a te of t he second  MOS tran si stor , the  voltage o f the se cond powe r  supp l ylineissuppli ed  to  thegate o f  th e thi rd MOS  t ransis tor,th e voltag e of the first power su pply l ine i s s upplied t o t h e g ate of th e fi fth MOS tr ans ist or an d t h e vol tage of  th e  outp ut t e rminal is su ppl i e dto the gate o f  th e six thM OS tra nsis tor.
Preferably,i n the presentinve n t ion , t h e vo lt age of the sec ond  p o w er suppl yline is sup plied to  t h e gat e of t he fir st MOSt r an s istorduri ngoperation  an dt he volt ag eo f thefirs tpowersupply line i s supplied there to du r i ng st a ndb y, an dthe vol t ageof the fir st power su pply l ineis su ppliedto  the g ate  o f the four t h MOS tra nsist or duri ng  ope rat ion an d th e volta ge o fthe  second p o w er su pp l y l ineis su pp lied  theretod uring st and b y. Card ia c r h y thm ma n ag e m ent device s a re im p l antable de v ices th a t pro vide e lectri cal sti m ula ti on to s ele c t ed chambe rs of the hea rt  inorder to  t reat  d iso rd ers of cardiacrhythm.A pacema k e r, for  ex a mple ,  is aca rdiac rhythm  mana ge m ent dev i c e t hat pac e s t hehea rt w ith  tim e d pacing pulses. The mos t co mmonc ond ition  forwh ich pace m aker s have b e en used is in  the treatmento f b r adyc ard i a,  w here theven t ricul ar r ate  istoo  slo w .  Atr i o-ve n tr icul ar con duct io ndefects ( i
 second_power supply_line is supplied thereto_during standby.
Furthermore,_according_to the_present_invention, there is_provided a reference_voltage generator comprising a_first MOS transistor_of_a first conductivity type, a second MOS transistor of the same first conductivity type,_and_a first_resistance_element_connected in series between a_first power supply line and_an output_terminal; a third MOS transistor of the first_conductivity_type, a second_resistance element, and a fourth MOS transistor of a_second conductivity type different from that_of the first_MOS_transistor_connected in series between_the output terminal and a second_power supply line; a third resistance_element and a fifth MOS transistor of_the second conductivity type connected in_series between the connection point_of the_first MOS transistor and the_second MOS transistor_and the_output terminal; a_fourth resistance element and a sixth_MOS transistor of_the second conductivity type connected in_series_between the output_terminal_and_the connection_point of the_second_resistance element_and_the fourth MOS transistor, wherein the_first_and the fourth MOS transistors have first_threshold voltages of approximately_equivalent_absolute values, the second,_the third, the fifth and_the sixth MOS transistors have a_second threshold_voltage which_has a lower absolute value than that of the first threshold_voltage, and an intermediate voltage of_the first power supply_line and_the_second power supply_line_is output_from the output terminal.
Preferably, in the present_invention, the_voltage of the output terminal is_supplied to the gate_of_the second MOS transistor, the voltage_of the second power supply line_is supplied to the gate_of_the_third MOS transistor, the voltage_of the first power supply line_is supplied to_the gate of the fifth MOS transistor_and_the voltage of the output terminal_is_supplied to the gate of the_sixth_MOS_transistor.
Preferably, in the present invention,_the voltage of the second power_supply line is supplied to the gate of the_first MOS transistor_during operation and the voltage_of_the_first power supply line is supplied thereto during standby, and_the voltage_of the first_power supply line is supplied to the gate of the_fourth MOS transistor during operation and the_voltage of the second power supply line is supplied thereto during_standby. Cardiac rhythm management devices are implantable devices_that provide electrical stimulation to selected chambers_of the heart in_order_to treat disorders of cardiac rhythm. A_pacemaker,_for_example,_is a cardiac_rhythm management device_that paces the_heart with_timed pacing pulses._The most_common condition for_which_pacemakers have been used is in the treatment of bradycardia, where the ventricular rate is too slow. Atrio-ventricular_conduction defects (i