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-voltagedrop
power-supply ORing. The MAX5944 operates over
the 7.5V to 37V input range and provides inrush and output
current limit in addition to diode ORing functions suitable
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 functions.
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 protect
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
10µA supply current per channel.
The MAX5944 operates over the -40°C to +85°C
extended temperature range and is available in a
16-pin SO package.
Key Features
Applications/Uses
Provides Safe Hot-Swap for 7.5V to 37V Power Supplies
Dual-Channel Hot-Swap
Low-Drop Power ORing with Ultra-Fast Turn-Off
Active Current Limit
±5% Current-Limit Sensing Accuracy
2ms Current-Limit Timeout
Fast Current-Limit Response to Output Short-Circuit Conditions
Drives External n-Channel Power MOSFETs
Independent Overcurrent Fault Status Outputs
259ms Autoretry Period
10µA (Per Channel) Shutdown Current
Independent ON/OFF Control Allows Undervoltage Lockout Programming
Fast Load Disconnect Control Through ON/OFF Inputs
Notes: *This pricing is BUDGETARY, for comparing similar parts. Prices are in
U.S. dollars and subject to change. Quantity pricing may vary
substantially and international prices may differ due to local
duties, taxes, fees, and exchange rates. For volume-specific prices
and delivery, please see the price and availability page
or contact an authorized distributor.