®
RT9728B
120mΩ, 1.8A Power Switch with Adjustable Current Limit
General Description
Features
z
10% Current Limit Accuracy @ 1.3A
The RT9728B is a cost effective, low voltage, single
P-MOSFET power switch IC for USB application with a
adjustable current limit feature. Low switch-on resistance
(typ. 120mΩ) and low supply current (typ. 120μA) are
realized in this IC. The RT9728B can offer a adjustable
current limit threshold between 75mA and 1.8A (typ.) via
an external resistor. The 10% current limit accuracy can
be realized for all current limit settings. In addition, a flag
output is available to indicate fault conditions to the local
USB controller. Furthermore, the chip also integrates an
embedded delay function to prevent mis-operation due to
high inrush current. The RT9728B is an ideal solution for
USB power supplies and can support flexible applications
since it is suitable for various current limit requirements.
It is available in the SOT-23-6 and WDFN-6L2x2 packages.
z Adjustable Current Limit : 75mA to 1.8A (typ.)
z Meets USB Current Limiting Requirements
z Operating Voltage Range : 2.5V to 5.5V
z Reverse Input−Output Voltage Protection
z Built-in Soft-Start
z 120mΩ P-MOSFET
z 120μA Supply Current
z RoHS Compliant and Halogen Free
Ordering Information
RT9728B
Package Type
E : SOT-23-6
QW : WDFN-6L 2x2
Lead Plating System
G : Green (Halogen Free and Pb Free)
Applications
z USB Bus/Self Powered Hubs
H : Chip Enable High
L : Chip Enable Low
Note :
z USB Peripheral Ports
z ACPI PowerDistribution
Richtek products are :
z Battery Power Equipment
z 3G/3.5GData Card, Set-Top Boxes
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
Simplified Application Circuit
VIN
VOUT
V
OUT
V
IN
C
IN
RT9728B
R
FAULT
R
ILIM
ILIM
FAULT Signal
FAULT
EN/EN
Enable
GND
Copyright 2013 Richtek Technology Corporation. All rights reserved.
©
is a registered trademark of Richtek Technology Corporation.
DS9728B-00 August 2013
www.richtek.com
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