| 摘要 |
<p>PURPOSE:To prevent the destruction of an EEPROM within a card by performing the ON/OFF control of a program power supply based on the output of a detection means detecting the voltage of a logic power supply. CONSTITUTION:An IC memory card 10 is supplied with a logic voltage Vcc as well as a program voltage Vpp via a power supply control circuit 20. The circuit 20 outputs or cut off the voltage Vpp based on the voltage Vcc. That is, when the voltage Vcc is 5V, the circuit 20 is turned on to cause the externally applied voltage Vpp (12V) to be supplied to an EEPROM 13; while when the voltage Vcc is 0V, the circuit 20 is turned off to cause the externally applied voltage Vpp to be cut off. Accordingly, when the voltage Vcc is cut off even if the voltage Vpp is externally applied, the voltage Vpp is also cut off. Thus, the destruction of the EEPROM 13 can be prevented.</p> |
