| 摘要 |
<p>PURPOSE:To stably hold data and at the same time to reduce the power consumption of a memory card by connecting a single end of a charging capacitor to an external power connection circuit and including an inverter circuit into a memory control input circuit so as to stably inactivate a logical signal. CONSTITUTION:In a transfer state or a working state where a memory card 1 is attached to an external equipment, the power voltages VC1 and VC2 of the external equipment are kept at the same level and simultaneously and slowly rise while charging a capacitor C. An external negative logical signal, the inverse of phi1 has a satisfactorily high level to both voltages VC1 and VC2 together with the inverted output VX1 of an inverter I1 kept at a satisfactorily low level respectively. Thus a memory negative logical signal, the inverse of phi2 outputted from an inverter I2 is kept at a high level with higher stability than conventional. When the card 1 is detached from the external equipment and carried out, the voltage of the signal, the inverse of phi1 drops slowly line the VC1 via a pull-up resistance R1. Meanwhile the VC2 drops suddenly and therefore the output voltage VX1 of the inverter I1 is quickly set at a low level like the VC2. Thus it is possible to easily keep a low level of the nodal point voltage VX1 where no malfunction is produced even with the noises mixed from outside.</p> |
