Security Supervisor Chips Protect POS Systems

The STM140x security supervisor chip family from STMicroelectronics takes aim at point-of-sale (POS) terminal applications. With these pin- and plug-in compatible chips, designers can easily upgrade systems as new features are needed.

Consuming just 2.8 µA, the security supervisors stake a claim as the world's first chips to integrate all of the functions for detecting physical and environmental intrusion required by the major security standards. All of the chips are designed for the High Security Module (HSM) used by various POS applications.

Able to continuously monitor physical tamper units and switches, primary and battery-backup supply voltages, and ambient temperature, the chips can raise an alarm if they detect any attempt at intrusion. The alarm also can be used to "zeroize" the cryptographic keys stored in secure memory in the HSM, inhibiting further access. A number of national, international, and industry-specific standards define security requirements for POS equipment.

The STM1403C and 1403A target FIPS-140 Security level 3. They provide more than seven key supervisor functions, including low-power-supply and low-battery-voltage detection, auto battery switchover, overvoltage and undervoltage alarms, and four physical tamper inputs. The STM1403A also offers a 1.237-V reference output voltage for use with an external analog-to-digital converter.

Housed in 3-mm² 16-lead QFN packages, the STM1403C and 1403A cost $1.50 and $1.65, respectively, in large quantities. The STM1404 series, due for release later this quarter, supports the highest security level (Level 4) of the FIPS-140 standard. It will provide a superset of features offered by the STM1403 series, including overtemperature and undertemperature alarms.