LMC6953 Datasheet | National Semiconductor

Description The LMC6953 is a voltage supervisory chip designed to meet PCI (Peripheral ponent Interconnect) Specifications Revision 2.1. It monitors 5V and 3.3V power supplies. In cases of power-up, power-down, brown-out, power failure and manual reset interrupt, the LMC6953 provides an active low reset. RESET holds low for 100 ms after both 5V and 3.3V powers recover, or after manual reset signal returns to high state. The external capacitor on pin 8 adjusts the reset delay. This part is ideal on PCI motherboards or add-in cards to ensure the integrity of the entire system when there is a fault condition. The active low reset sets the microprocessor or local device in a known state. The LMC6953 has a built-in bandgap reference that accurately determines all the threshold voltages. The internal reset delay circuitry eliminates additional discrete ponents. Features n pliant to PCI specifications revision 2.1. n Under and over voltage detectors for 5V and 3.3V n Power failure detection (5V falling under 3.3V by 300 m V max) n Manual reset input pin n Guaranteed RESET assertion at VDD = 1.5V n Integrated reset delay circuitry n Open drain output n Adjustable reset delay n Response time for over and under voltage detection: 490 ns Max n Power failure response time: 90 ns Max n Requires minimal external ponents Applications n Desktop PCs n PCI-Based Systems n Network servers Typical Application Circuits On Mother Board On Add-in Cards DS012846-23 DS012846-24 © 1998 National Semiconductor Corporation DS012846 .national. Connection Diagram 8- Pin SO DS012846-2 Top View Ordering Information Package 8-Pin Small Outline Industrial Temp Range - 40˚C to +85˚C LMC6953CM LMC6953CMX NSC Drawing M08A Supplied As Rails 2.5k Tape and Reel .national. Absolute Maximum Ratings (Note 1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. ESD Tolerance (Note 2) Human...