ISL6436 Datasheet, PDF (1/12 Pages) Intersil Corporation – USB Dual Port Power Supply Controller

TM
Data Sheet
ISL6436
August 2001
File Number 9023
USB Dual Port Power Supply Controller
The ISL6436 is a USB dual port power controller, fully
independent overcurrent (OC) fault protection IC.
Operational over the +2.5V to +5.5V range, this device
features internal current monitoring, accurate current
limiting, integrated power switches and current limited
delay to latch-off for system protection.
The ISL6436 current sense and limiting circuitry sets the
current limit to a nominal 1A, making this device well suited for
the USB port power management application. The ISL6436
provides OC fault notification, accurate current limiting and a
consistent timed latch-off thus isolating and protecting the
voltage bus in the presence of an OC event or short circuit. The
12ms time to latch-off is independent of the adjoining switch’s
electrical or thermal condition and the OC response time is
inversely related to the OC magnitude.
Each ISL6436 incorporates in a single 8 lead SOIC
package two 80mΩ N-channel MOSFET power switches
for power control. Each switch is driven by a constant
current source giving a controlled ramp up of the output
voltage. This provides a soft start turn-on eliminating bus
voltage drooping caused by inrush current while charging
heavy load capacitances. Independent enabling inputs and
fault reporting outputs for each channel are compatible with
3V and 5V logic to allow external control and monitoring.
The ISL6436 undervoltage lockout feature prevents turn-on
of the outputs unless the correct ENABLE state and VIN >
2.5V are present. During initial turn-on the ISL6436
prevents fault reporting by blanking the fault signal. Rising
and falling outputs are current limited voltage ramps so that
both the inrush current and voltage slew rate are limited,
independent of load. This reduces supply droop due to
surge and eliminates the need for external EMI filters.
During operation, once an OC condition is detected the
appropriate output is current limited for 12ms to allow
transient conditions to pass. If still in current limit after the
current limit period has elapsed, the output is then latched
off and the fault is reported by pulling the corresponding
FAULT low. The FAULT signal is latched low until reset by
the ENABLE signal being de-asserted at which time the
FAULT signal will clear.
Features
• 80mΩ Integrated Power N-channel MOSFET Switches
• Accurate Current Sensing and 1A Current Limiting
• 12ms Fault Delay to Latch-Off, No Thermal Dependency
• 2.5V to 5.5V Operating Range
• Disabled Output Internally Pulled Low
• Undervoltage Lockout
• Controlled Turn-on Ramp Time
• Channel Independent Fault Output Signals
• Compatible with 3.3V and 5V Logic Families
• Channel Independent Logic Level Enable High Inputs
(ISL6436H) or Enable Low Inputs (ISL6436L)
Applications
• USB Port Power Management
• Electronic Circuit Limiting and Breaker
Ordering Information
PART NUMBER
ISL6436LIB
ISL6436LIB-T
TEMP.
RANGE
(^oC)
PACKAGE
PKG. NO.
-40 to 85 8 Lead SOIC
M8.15
-40 to 85 8 Lead SOIC Tape and Reel
ISL6436HIB
-40 to 85 8 Lead SOIC
M8.15
ISL6436HIB-T
-40 to 85 8 Lead SOIC Tape and Reel
ISL6436EVAL1
Evaluation Platform
ISL6436USBEVAL1 USB Dual Port Evaluation Platform
Pinout
ISL6436 (SOIC)
TOP VIEW
GND ₁
VIN 2
ENABLE_1 3
ENABLE_2 4
8 FAULT_1
7 OUT_1
6 OUT_2
5 FAULT_2
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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