| 摘要 |
PURPOSE:To enable integration while improving temperature characteristics by eliminating the variation of manufacture by forming transistors (TR) differing in threshold voltage on the same semiconductor substrate, and utilizing a difference between those voltages. CONSTITUTION:For example, MOSTRs 2 and 3 has a difference DELTAVth in threshold voltage Vth and their other characteristics are exactly the same. When the output state of a differential input voltage comparing circuit composed of TRs 2-6 is inverted, namely, when a differential output voltage E2 is zero, (eta1- eta2)E1=DELTAVth, where E1 is a battery voltage and also a detection voltage Vdet on said condition). Therefore, the detection voltage Vde is expressed by simple equation Vdet=DELTAVth/(eta1-eta2)=DELTAVth/eta2. In this case, eta2=eta1-eta2. Since eta1 and eta2 in the equality are the ratio of the division of a power voltage by resistances 7-8, and 9-10, precise determination is performed even by thin film resistance, diffused resistance, etc. On the other hand, the difference DELTAVth in threshold voltage is controllable with high precision. Therefore, the detection voltage Vdet is also realized precisely and adjustment is facilitated. |
