ISL6161
Dual Power Distribution Controller
Key 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)
Description
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.
Applications
- PCI-Express Applications
- Power Distribution and Control
- Hot Plug, Hot Swap Components
