IMP802 Datasheet | IMP Inc

features of these four functions are: a) 1.6 second watchdog timer to keep microprocessor responsive b) c) 4.40V or 4.65V VCC threshold for microprocessor reset at power-up and power-down SPDT (single-pole, double-throw) PMOS switch connects backup power to RAM if VCC fails Key Features x Design improvement over Maxim MAX690A/692A/802L/802M/805L - 70% lower current than Maxim: 100µA maximum - RESET Operation to 1.1V x Two precision supply-voltage monitor options - 4.65V (IMP690A/802L/805L) - 4.40V (IMP692A/802M) x Battery-backup power switch on-chip x Watchdog timer: 1.6 second timeout x Power failure/low battery detection x Short-circuit protection and thermal limiting x Small 8-pin SO package x No external ponents x Specified over full temperature range d) 1.25V threshold detector for power loss or general purpose voltage monitoring While these features are pin- patible with the industry standard power- supply supervisors offered by Maxim, the IMP devices are superior replacements and can reduce power requirements by 70 percent when pared to Maxim MAX690/MAX692A/MAX802L/MAX802M/ MAX805L devices. Short-circuit and thermal protection have also been added. The IMP690A/IMP802L/IMP805L generate a reset pulse when the supply voltage drops below 4.65V, and the IMP692A/IMP802M generate a reset below 4.40V. The IMP802L/IMP802M have power- fail accuracy to ±2%. The IMP805L is the same as the IMP690A except that RESET is provided instead of RESET. Applications x Embedded control systems x Battery- operated systems x Intelligent instruments x Wireless munication systems x PDAs and handheld equipment x µP/µC power supply monitoring Block Diagrams VBATT VCC + Typical Application 1 7 VOUT RESET (RESET) Unregulated DC 0.1µF PFI R2 Regulated +5V VCC RESET PFO WDI VOUT NMI I/O LINE GND BUS CMOS VCC RAM GND 690A_01.eps 8 2 Battery-Switchover Circuit Reset Generator + VCC RESET R1 1.25V 3.5V + Watchdog Timer + 6 WDI + + + - 3.6V Lithium Battery VBATT GND 0.8V 4...