The STM690A/692A/703/704/802/805/817/818/819 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 VCCinput for an out-of-tolerance condition. When an invalid VCCcondition occurs, the reset output (RST) is forced low (or high in the case of RST). These devices also offer a watchdog timer (except for STM703/704/819) as well as a power-fail comparator (except for STM818) 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.
**Key Features**
5 V operating voltage
NVRAM supervisor for external LPSRAM
Chip-enable gating (STM818 only) for external LPSRAM (7 ns max prop delay)
RST andRST outputs
200 ms (typ) trec
Watchdog timer - 1.6 sec (typ)
Automatic battery switchover
Low battery supply current - 0.4 μA (typ)
Power-fail comparator (PFI/PFO )
Low supply current - 40 μA (typ)
GuaranteedRST (RST) assertion down to VCC = 1.0 V
Operating temperature: –40 °C to +85 °C (industrial grade)
RoHS compliance
Lead-free components are compliant with the RoHS directive
