The LTC®1536 is designed for PCI local bus applications with multiple supply voltages that require low power, small size, high speed and high accuracy supply monitoring. For 3.3V and 5V supplies that are >500mV below spec or for the condition when the 5V supply falls below the 3.3V supply, the LTC1536 has a very fast response time capable of meeting the PCI tFAIL timing specification. Tight 0.75% threshold accuracy and glitch immunity ensure reliable reset operation without false triggering. The RST output is guaranteed to be in the correct state for Vcc5 or Vcc3 down to 1V. The 100µA typical supply current makes the LTC1536 ideal for power-conscious systems. A manual pushbutton reset input provides the ability to generate a very narrow “soft” reset pulse (100µs typ) or a 200ms reset pulse equivalent to a power-on reset. Both SRST and RST outputs are open-drain and can be OR-tied with other reset sources.