REFERENCE VOLTAGE GENERATION CIRCUIT AND REFERENCE VOLTAGE GENERATION METHOD

• Main Author: TAKEHARA SATOSHI
• Format: Patent
• Language: English; Japanese
• Published: 19.01.2015
• Subjects: BASIC ELECTRIC ELEMENTS; CONTROLLING; ELECTRIC SOLID STATE DEVICES NOT OTHERWISE PROVIDED FOR; ELECTRICITY; PHYSICS; REGULATING; SEMICONDUCTOR DEVICES; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

PROBLEM TO BE SOLVED: To provide a reference voltage generation circuit and a reference voltage generation method in which manufacturing variation in reference voltage arising from a difference in the characteristic of each individual circuit element is eliminated.SOLUTION: A nonvolatile storage element is arranged in which two nonvolatile storage elements are with a tunnel oxide film and a nonvolatile storage element without a tunnel oxide film are arranged on each of a depletion side M1 and an enhancement side M2, their control gates and floating gates being connected. A threshold Vth is adjusted by an M1w and an M2w, respectively. Since the M1w and an M1r have their control gates and floating gates connected, they have the same threshold value Vth. It is the M1r and an M2r that generates a reference voltage, and SW is not included in a current path. Furthermore, since the M1r and the M2r, to which a power supply voltage is applied, do not have the tunnel oxide film, there is no fluctuation in the threshold Vth caused by disturbance. 【課題】各々の回路素子の特性の相違に基づいて発生する基準電圧の製造バラツキを無くすようにした基準電圧発生回路及び基準電圧発生方法を提供すること。【解決手段】不揮発性記憶素子をディプレッション側Ｍ１、エンハンスメント側Ｍ２それぞれトンネル酸化膜がある不揮発性記憶素子とトンネル酸化膜がない不揮発性記憶素子の２つをコントロールゲートとフローティングゲートをつなげた不揮発性記憶素子を配置する。閾値Ｖｔｈの調整はそれぞれＭ１ｗ，Ｍ２ｗで行う。Ｍ１ｗとＭ１ｒはコントロールゲート、フローティングゲートがつながっているため、同じ閾値Ｖｔｈになる。基準電圧を生成するのはＭ１ｒ，Ｍ２ｒで電流パスにＳＷは入らない。また、電源電圧を印可するＭ１ｒ，Ｍ２ｒにはトンネル酸化膜がないのでディスターブによる閾値Ｖｔｈの変動もない。【選択図】図７