Dual Firewire Current Limiter And Low-drop Oring

The MAX5944 is a dual, current limiter/low-drop ORing, Switch controller power-management IC for FireWire applications. Each independent channel controls two external Power MOSFETs to regulate current from the input power supply to the load and performs low-voltage- drop power-supply ORing. The MAX5944 operates over the 7.5V to 37V input range and provides inrush and out- put current limit in addition to Diode ORing functions suit- able for FireWire applications. The MAX5944 allows the safe insertion and removal of FireWire peripherals into a live FireWire port by providing inrush current control and output current-limiting func- tions. The MAX5944 features a current-limit function that actively limits the current drawn by the load with a 2ms timeout. Its autoretry function then automatically restarts after the 259ms autoretry delay time. The ORing feature provides a very efficient way to pro- tect the FireWire port when connected to another FireWire peripheral that sources a higher voltage. By turning off the external MOSFETs the MAX5944 provides a true bidirectional load disconnect. Each channel has an independent ON/OFF control that results in less than 10A supply current per channel. By Maxim Integrated Products