19-2254; Rev 1; 12/02
1A Current-Limited Switch for 2 USB Ports
General Description
The MAX1922 current-limited 70mΩ switch with built-in
fault blanking provides an accurate, preset 1.4A to 2.1A
current limit, making it ideal for dual USB applications.
Its low quiescent supply current (16µA) and standby
current (1µA) conserve battery power in portable appli-
cations. The MAX1922 operates with inputs from 2.7V
to 5.5V, making it ideal for both 3V and 5V systems.
An overcurrent signal (OC) notifies the microprocessor
that the internal current limit has been reached. A 10ms
overcurrent-blanking feature allows momentary faults
(such as those caused when hot-swapping into a
capacitive load) to be ignored, thus preventing false
alarms to the host system. This blanking also prevents
an
OC
signal from being issued when the device is
powering up.
The MAX1922 has several safety features to ensure that
the USB port is protected. Built-in thermal-overload pro-
tection limits power dissipation and junction tempera-
ture. The device also has accurate internal current-
limiting circuitry to protect the input supply against
overload.
The MAX1922 is offered in a space-saving 8-pin SO
package and operates over the extended (-40°C to
+85°C) temperature range.
♦
10ms Internal
OC
Blanking Timeout
♦
OC
Blanking During Power-Up
♦
125mΩ max High-Side MOSFET
♦
Short-Circuit and Thermal Protection with
Overcurrent Logic Output
♦
Undervoltage Lockout
♦
16µA Quiescent Supply Current
♦
1µA (max) Standby Supply Current
♦
2.7V to 5.5V Supply Range
♦
UL Recognized: UL# E211935
Features
♦
Accurate Current Limit (1.4A min, 2.1A max)
MAX1922
Ordering Information
PART
MAX1922ESA
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
8 SO
Applications
Notebook Computers
USB Ports
USB Hubs
Docking Stations
Pin Configuration
TOP VIEW
INPUT
2.7V TO 5.5V
Typical Operating Circuit
IN
GND
IN
IN
1
2
8
7
OUT
OUT
OUT
OC
ON
OFF
EN
GND
OC
OUT
OUTPUT
MAX1922
MAX1922
3
6
5
EN
4
SO
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
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