FN9023 Rev 0.00

Page 1 of 13

Aug 10, 2001

FN9023

Rev 0.00

Aug 10, 2001

ISL6436

USB Dual Port Power Supply Controller

DATASHEET

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 80m

 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

•80m

 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

Pinout

ISL6436 (SOIC)

TOP VIEW

Ordering Information

PART NUMBER

TEMP.

RANGE

(oC)

PACKAGE

PKG. NO.

ISL6436LIB

-40 to 85 8 Lead SOIC

M8.15

ISL6436LIB-T

-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

1

2

3

4

8

7

6

5

VIN

OUT_1

OUT_2

FAULT_1

FAULT_2

GND

ENABLE_1

ENABLE_2