| 摘要 |
PURPOSE:To secure the stable internal voltage regardless of a current consumption amount by combining a current route formed by a series circuit of a constant current control means and a detecting resistance and a current consumption means which compensates the change of current consumption of an internal circuit. CONSTITUTION:An end of a constant current element Q1 is connected to an input terminal T1 of a power supply circuit, and a detecting resistance R1 and a constant voltage element DZ are connected in series between a common terminal T3 and the other end of the element Q1. A bridge of resistances R2-R5 is connected to the gate of the element Q1 via an operational amplifier Q2; while a resistance R11 is connected from a bridge of resistances R6-R10 via an operational amplifier Q3. Thus a receiving current I1 is constant as long as the voltage EZ of the element DZ is kept constant. Then both currents I3 and I4 are also fixed. In addition, the internal voltage Ei is constant regardless of the value of the current I3 as long as the current I1 and a current (I3+I4) are kept constant. Then a circuit to be energized can consume the current within a range of (I3+ I4). |
