Chip protection device for preventing unauthorised access to integrated circuit chip, esp. non-volatile memories e.g. EEPROM

摘要

The device makes the chip accessible in dependence on a comparison of input data with predetermined unlocking data. The device includes a switch unit. This allows a voltage to be applied to a permanently separable electrical conduction path when the input data matches the predetermined unlocking data. The predetermined unlocking data may be provided in the chip and may be adjusted by hardware through selectively interrupting the conductive path while manufacturing the chip. The switch unit may be a component of a high voltage generator (2). The device may have a construction such that the separation of the conductive path a variable level of an output signal from the access protection device.