Santa Clara, CA--November 25, 1996--National Semiconductor Corp. (Santa Clara, CA) announced a voltage supervisory chip designed, tested, and guaranteed to meet revision 2.1 of the PCI (Peripheral Component Interconnect) specifications.
The LMC6953 monitors both 3.3V and 5V supplies during power-up, power-down, brownout, power failure, and manual reset interrupt. It then generates a reset output if either supply fluctuates from the designated PCI specifications. The device also monitors the two supplies with respect to each other and, should polarities reverse, generates reset with a faster response in order to prevent catastrophic failure of any component on the bus. The LMC6953 is suitable for servers, desktop PCs, PCI add-in cards, and embedded PCI systems such as test equipment and communication servers.
Features include an accurate built-in bandgap reference that accurately determines all threshold voltages. Reset response time is 490 ns max. for brownout conditions and 90 ns for power failure. In accordance with PCI specifications, a precise reset delay timing of 100 ms occurs after both 5V and 3.3V powers recover, or after manual reset signal returns to high state. Using the LMC6953's open-drain outputs, designers can connect an external resistor so that the output can be used as a level shifter for mixed voltage systems up to 6V.
Available now in production quantities, the LMC6953CM and LMC6953CMX (8-pin SOICs) are priced at $1.89 each in 1,000-unit quantities.
Return to Headlines