Maxim's Secure Supervisor Supports FIPS 140-2 Levels 3 and 4

The DS3645 provides active tamper detection with rapid erasure of key memory, and is packaged in a leadless CSBGA for enhanced security. Eight uncommitted external inputs allow design engineers to implement additional levels of security. Designed for applications requiring the highest level of security, this device supports FIPS 140-2 Levels 3 and 4, as well as the highest requirements of Common Criteria.

The most innovative feature of the DS3645 is the 4KB of proprietary on-chip nonvolatile SRAM it uses to store encryption keys. This memory architecture constantly complements the SRAM cells to eliminate the possibility of memory imprinting due to oxide stress, thereby preventing the passive detection of data remnants in stressed memory cells. Additionally, the DS3645 employs a high-speed, hardwired clearing function to erase the entire 4KB array in less than 100ns after a tamper alarm has been generated by the device.

The DS3645 provides tamper-detection inputs, as well as low-power continuous monitoring of system voltages, resistive meshes, external sensors, and digital interlocks. The RTC crystal oscillator is also monitored and invokes a tamper response if the frequency falls outside the set threshold. An internal digital temperature sensor with a programmable rate-of-change detector protects the DS3645's internal encryption-key memory from thermal attacks. The DS3645 constantly monitors primary power; in the event of failure, an external battery power source is automatically switched in to keep the SRAM, RTC, and tamper-detection circuitry alive.