资 源 简 介
The TC1267 is an applicaTIon-specific, low dropoutregulator (LDO), specifically intended for use in PCIperipheral card applicaTIons complying with PCI PowerManagement (PCI 2.0). It provides an uninterrupted,3.3V output voltage when the main (5V) or auxiliary(3.3V) input voltage supplies are present.The TC1267 consists of an LDO, a voltage thresholddetector, external switchover logic and gate drivecircuitry. It funcTIons as a convenTIonal LDO as long asthe voltage on the main supply input (VIN) is above thelower threshold (3.90V typical). Should the voltage onVIN fall below the lower threshold, the LDO is disabledand an external P-channel MOSFET is automaticallyturned on, connecting the auxiliary supply input toVOUT, and ensuring an uninterrupted 3.3V output. Themain supply is automatically selected, if both the mainand auxiliary input supplies are present, and transitionfrom one input supply to the other is ensured glitchfree.High integration, automatic secondary supplyswitchover, Kelvin sensing, and small size make theTC1267 the optimum LDO for PCI 2.0 applications.
