SUMMARY DESCRIPTION

The STM690/704/795/802/804/805/806 Supervisors are self-contained devices which provide microprocessor supervisory functions with the ability to non-volatize and write-protect external LPSRAM. A precision voltage reference and comparator monitors the VCC input for an out-of-tolerance condition. When an invalid VCC condition occurs, the reset output (RST) is forced low (or high in the case of RST). These devices also offer a watchdog timer (except for STM704/795/806) as well as a power-fail comparator (except for STM795) to provide the system with an early warning of impending power failure.

These devices are available in a standard 8-pin SOIC package or a space-saving 8-pin TSSOP package.

FEATURES SUMMARY

■ RST OR RST OUTPUTS

■ NVRAM SUPERVISOR FOR EXTERNAL LPSRAM

■ CHIP-ENABLE GATING (STM795 only) FOR EXTERNAL LPSRAM (7ns max PROP DELAY)

■ MANUAL (PUSH-BUTTON) RESET INPUT

■ 200ms (TYP) trec

■ WATCHDOG TIMER - 1.6sec (TYP)

■ AUTOMATIC BATTERY SWITCHOVER

■ LOW BATTERY SUPPLY CURRENT - 0.4µA (TYP)

■ POWER-FAIL COMPARATOR (PFI/PFO)

■ LOW SUPPLY CURRENT - 40µA (TYP)

■ GUARANTEED RST (RST) ASSERTION DOWN TO VCC = 1.0V

■ OPERATING TEMPERATURE: –40°C to 85°C (Industrial Grade)