The ISL6161 is a HOT SWAP dual supply power distribution

controller that can be used in PCI-Express applications.

Two external N-Channel MOSFETs are driven to distribute

and control power while providing load fault isolation. At

turn-on, the gate of each external N-Channel MOSFET is

charged with a 10μA current source. Capacitors on each

gate (see the “Typical Application Diagram” on page 1),

create a programmable ramp (soft turn-on) to control in-rush

currents. A built-in charge pump supplies the gate drive for

the 12V supply N-Channel MOSFET switch.

Overcurrent protection is facilitated by two external current

sense resistors and FETs. When the current through either

resistor exceeds the user programmed value, the controller

enters the current regulation mode. The time-out capacitor,

CTIM, starts charging as the controller enters the time-out

period. Once CTIM charges to a 2V threshold, both the

N-Channel MOSFETs are latched off. In the event of a hard

and fast fault of at least 3x the programmed current limit

level, the N-Channel MOSFET gates are pulled low

immediately before entering the time-out period. The

controller is reset by a rising edge on the ENABLE pin.

The ISL6161 constantly monitors both output voltages and

reports either one being low on the PGOOD output as a low.

The 12V PGOOD Vth is ~10.8V and the 3.3V Vth is ~2.8V

nominally.

Features

? HOT SWAP Dual Power Distribution and Control for

+12V and +3.3V

? Provides Fault Isolation

? Programmable Current Regulation Level

? Programmable Time-Out

? Charge Pump Allows the Use of N-Channel MOSFETs

? Power-Good and Overcurrent Latch Indicators

? Adjustable Turn-On Ramp

? Protection During Turn-On

? Two Levels of Current Limit Detection Provide Fast

Response to Varying Fault Conditions

? 1μs Response Time to Dead Short

? 3μs Response Time to 200 Current Overshoot

? Pb-Free Available (RoHS compliant)

Applications

? PCI-Express Applications

? Power Distribution and Control

? Hot Plug, Hot Swap Components