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 requirements of the FIPS 140.2, Common Criteria, PCI PED, and EMV® 4.1 certification agencies. 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 tamper-detection 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
