| 摘要 |
PURPOSE:To easily reduce a source voltage and current consumption and to set an optional output voltage by setting the 1st resistance and the 2nd resistance and adjusting the 3rd resistance, and obtaining a reference voltage from the 3rd resistance. CONSTITUTION:An operating current is flowed to a resistance R23 from a transistor (TR)Q22 by TRs Q26 and Q27 constituting a current mirror circuit to cause a voltage drop V1. The base-emitter voltage of a Q23, on the other hand, is converted into a current by a resistance 22, and the current mirror circuit consisting of TRs Q28-Q30 fixes the operating current of the Q23 and flows a mirror current by the resistance R23 and Q30 to cause a voltage drop V2. A reference voltage Vref=V1+V2 is developed across the resistance 23. This voltage is differentiated by absolute temperature T to calculate the temperature coefficient of the reference voltage. Consequently, a zero temperature coefficient is set only with the ratio of resistances R21 and R22 and the resistance R23 is adjusted to obtain an optional reference voltage. |
