| 摘要 |
PURPOSE:To obtain a semiconductor IC containing both analog and digital circuits with which the power consumption is reduced, and the constituting IC is achieved by supplying the power only to the analog circuit. CONSTITUTION:A power supply ON signal is fed to an interface (INF)21 from a digital control circuit 11, and the output of the gate G1 turns off a transistor TRTv. Then the current mirror circuits of TRT1 and T2 flow a current I1 equal to that of a constant current source 20 to a TRT5. Furthermore a current I1 is supplied to the INF21 by the current mirror circuits of TRT5 and T6 as well as TRT3 and T4, and the INF21 is turned on. When the INF21 is turned off, the INF21 is made inactive by a logic signal via a gate G2 and then a TRT7 is turned on by a power supply OFF signal input. Then the supply of current is stopped to the TRT5 and T6, and then the supply of current is cut to the INF21. |
