发明名称 |
VERFAHREN ZUR STEUERUNG DER LADE- UND ENTLADEPHASEN EINES STÜTZKONDENSATORS |
摘要 |
A method for controlling the charging and discharging phases of a backup capacitor for a data storage medium has the step where the backup capacitor is first discharged to a defined voltage level before it is charged. The capacitor is discharged using a constant current. This ensures that the charging current for the backup capacitor cannot be used to identify what the charge-state of the capacitor was before discharging. Therefore, it is no longer possible to infer the currents that flowed during security-related arithmetic operations in a data processing unit. In one advantageous circuit configuration, a constant current source is formed by a current-mirror circuit, and a comparator is used to compare the voltage on the backup capacitor with a bandgap reference. |
申请公布号 |
DE50105327(D1) |
申请公布日期 |
2005.03.17 |
申请号 |
DE2001505327 |
申请日期 |
2001.11.06 |
申请人 |
INFINEON TECHNOLOGIES AG |
发明人 |
TSCHETERNIGG, SIEGFRIED;WEDEL, ARMIN |
分类号 |
G06K19/073;H02J9/06;(IPC1-7):G06K19/073 |
主分类号 |
G06K19/073 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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