The MAX5943AEEE is a fully integrated power-management IC for FireWire applications. This device controls two external power n-channel MOSFETs to regulate current from the input power supply to the load and performs low-voltage-drop, power-supply ORing. The MAX5943AEEE operates over a 7.5V to 37V input range and provides inrush and output current limit in addition to a diode ORing function suitable for FireWire applications. The MAX5943AEEE FireWire/IEEE 1394 protective circuit (Figure 12 of the full data sheet) is UL recognized. The MAX5943AEEE allows the safe insertion and removal of FireWire peripherals into a live FireWire port by providing inrush current control and an output current-limiting function. The ORing feature provides a very efficient way to protect the FireWire port when connected to another FireWire peripheral that sources a higher voltage. By turning off both external MOSFETS, the MAX5943AEEE provides a true bidirectional load disconnect. A low-current shutdown mode disables the MAX5943, resulting in less than 10μA supply current. A pin-selectable input allows latched or autoretry fault management after a fault. The MAX5943A features a current-limit function that actively limits the current drawn by the load with a programmable timeout. The MAX5943B–MAX5943E do not actively limit the load current but provide a circuit-breaker function. See the Selector Guide in the full data sheet for the default and programmable circuit-breaker timeouts. The MAX5943AEEE operates over the -40°C to +85°C extended temperature range and is available in a 16-pin QSOP package.
Feature
- Provides Safe Hot Swap for 7.5V to 37V Power Supplies
- UL-Recognized FireWire/IEEE 1394 Protective Circuit
- Low-Drop Power ORing with Ultra-Fast Turn-Off
- Programmable Active Current Limit (MAX5943A)
- Programmable Circuit Breaker (MAX5943B–MAX5943E)
- ±5% Current-Limit Sensing Accuracy
- Programmable Current-Limit/Circuit-Breaker Timeout
- Fast Current-Limit Response to Output Short-Circuit Conditions (MAX5943A)
- Drives External n-Channel Power MOSFETs
- Overcurrent Fault Status Output
- Latched or Autoretry Overcurrent Fault Management
- 10μA Shutdown Current
- ON/OFF Control Allows Undervoltage Lockout Programming
- Fast Load Disconnect Control Through ON Input
Applications
- FireWire? Desktop/Notebook Port
- FireWire? Hub
- FireWire? Peripheral Device Current Limit
- Hot Swap