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 50mΩ 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
50mΩ 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
•0.05Ω 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
R
L
C
L
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
| Intersil and Design is a trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2001, All Rights Reserved
