The MIC29311 is a 3A, fast response, low-dropout (LDO) voltage regulator. Using Micrel's proprietary Super eta PNPTM process, the MIC29311 offers exceptional dropout (600mV at 3A) and low ground current (60mA at 3A). Fast transient response allows it to recover quickly from large load changes while maintaining a steady output. The device can be sent into a "zero-current" off mode when the TTL compatible enable is brought low. Designed specifically for Universal Serial Bus (USB) applications, the MIC29311 works with USB power switches to provide an economical solution for self-powered hubs. The 5.1V output voltage is optimized to work with lower-cost high on-resistance USB power switches (300m) to provide a minimum of 4.75V at 500mA to downstream ports. Used with MIC2527 quad USB power switches, the MIC29311 can power up to 6 downstream ports. Features of the MIC29311 include thermal shutdown, current limit, reversed-battery and reversed-lead insertion protection. An overvoltage clamp is available to maintain a safe output when the input voltage exceeds 8V. An error flag is also available to indicate of the output falls out of regulation, or when an overcurrent condition occurs. The MIC29311 is available in a 5-pin TO-220 or TO-263 package with a fixed 5.1V output voltage. For other high current, low-dropout voltage regulators, please see the MIC29150/300/500/750 and the MIC29310, MIC29510, MIC29710.