1

®

FN9004.2

ISL6121

Single Supply Integrated Current Limiting

Controller

The ISL6121 is a single supply Overcurrent (OC) fault

protection IC for 2.5V to 5V applications where 2A current

limiting is desired. This device features internal current

monitoring and limiting along with a 50m

Ω integrated power

switch and a current limited time out to latch-off feature for

system protection. The time to latch-off is independent of

device temperature, and magnitude of OC.

Each ISL6121 incorporates in a 8 lead SOIC package a

50m

Ω N-channel MOSFET power switch for power control.

The 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 in-

rush current while charging heavy load capacitances.

(Enable high (ISL6121H) and enable low (ISL6121L) options

are) available with a fault reporting output compatible with 3V

and 5V logic level signals allowing for external control and

monitoring.

The Under Voltage (UVLO) lockout feature prevents turn-on

of the output unless the correct ENABLE signal and VIN >

2.5V are both present. During initial turn-on the ISL6121

design prevents a fault from being presented by blanking the

fault signal, unlike other vendor devices needing additional

external circuitry to accomplish this. Rising and falling

output is a current-limited voltage ramp 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

output is current limited to 2A to allow for a transient

condition to pass. If still in current limit after the current limit

period has elapsed the output is latched off and the fault is

reported by pulling the FAULT low. The FAULT signal is

latched low until reset by the enable signal being deasserted

at which time the FAULT signal will clear.

See Figure 1 for typical application configuration

.

Features

•0.05

Ω Integrated Power N-channel MOSFET Switch

• Accurate Current Sensing and Limiting

• 12ms Timed Fault Latch-Off, No thermal Dependency

• 2.5V to 5.5V Operating Range

• Under Voltage Lockout

• Disabled Output Internally Pulled Low

• Controlled Turn On/Off Ramp Times

• Fault Output Signal

• Logic Level Enable High Inputs (ISL6121H) or Enable Low

Inputs (ISL6121L)

• Logic Level Compatible Enable Input and Fault Output

•

Pb-Free Available (RoHS Compliant)

Applications

• Fibre Channel

• Industrial Power Control

• Hot Plug

FIGURE 1. ISL6121 TYPICAL APPLICATION

1

2

3

4

8

7

6

5

EN

FAULT

VIN

OUT

OUT

VIN

OUT

GND

Ordering Information

PART

NUMBER

TEMP. RANGE

(°C)

PACKAGE

PKG.

DWG. #

ISL6121HIB

-40 to 85

8 Ld SOIC

M8.15

ISL6121HIBZA

(See Note)

-40 to 85

8 Ld SOIC

(Pb-free)

M8.15

ISL6121HIB-T

-40 to 85

8 Ld SOIC Tape and Reel

ISL6121HIBZA-T

(See Note)

-40 to 85

(Pb-free)

8 Ld SOIC Tape and Reel

ISL6121LIB

-40 to 85

8 Ld SOIC

M8.15

ISL6121LIBZA

(See Note)

-40 to 85

8 Ld SOIC

(Pb-free)

M8.15

ISL6121LIB-T

-40 to 85

8 Ld SOIC Tape and Reel

ISL6121LIBZA-T

(See Note)

-40 to 85

8 Ld SOIC Tape and Reel

(Pb-free)

ISL6121HEVAL1

Evaluation Platform

NOTE: Intersil Pb-free products employ special Pb-free material sets;

molding compounds/die attach materials and 100% matte tin plate

termination finish, which are RoHS compliant and compatible with

both SnPb and Pb-free soldering operations. Intersil Pb-free products

are MSL classified at Pb-free peak reflow temperatures that meet or

exceed the Pb-free requirements of IPC/JEDEC J STD-020C.

Data Sheet

November 12, 2004

CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.

1-888-INTERSIL or 321-724-7143

Copyright © Intersil Americas Inc. 2001, All Rights Reserved