The DS3640 is a secure supervisor with 1024 bytes of SRAM for applications requiring the secure storage of encryption keys, including POS terminals. The DS3640 supports the highest security level of the FIPS-140.2, Common Criteria, PCI-PED, and EMV-4.1 certification entities. The 1kB key memory is constantly complemented in the background to prevent oxide stress and memory imprinting. In the event of a qualified tamper event, the key memory is rapidly and completely cleared.
The device includes a real-time clock (RTC), CPU supervisor, watchdog timer, and on-chip temperature sensor. In the event of a primary power failure, an external battery source is automatically switched in to keep the key memory, RTC, and tamper-detection circuitry active. The DS3640 provides low-leakage tamperdetection inputs for interface to external sensors, interlocks, and anti-tamper meshes. The DS3640 will also invoke a tamper event if the backup battery drops below a specified threshold, absolute temperature or temperature rate-of-change exceeds programmed limits, or crystal-oscillator frequency falls outside a specified window. The tamper event is latched and time stamped for future debugging purposes.
Access to the RTC, tamper monitoring, key memory, and device configuration is conducted through an I²C-compatible interface. The DS3640 is assembled in a Pb-free BGA package, which enhances key security in that the leads are not exposed to the outer edges of the package.
Key Features
Applications/Uses
1024-Byte Non-Imprinting Key Memory with High Speed Erase
64-Byte General-Purpose RAM (Not Cleared)
RTC Watchdog Timer CPU Supervisor
Four General-Purpose Tamper Detect Comparators with Associated Reference
