MAX1946_10 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – Single USB Switch with Autoreset and Fault Blanking in Tiny TDFN

19-2550; Rev 3; 2/10
Single USB Switch with Autoreset and
Fault Blanking in Tiny TDFN
General Description
The MAX1946 single current-limited switch with auto-
reset supplies a guaranteed 500mA load in accordance
with USB specifications. The MAX1946 operates from a
2.7V to 5.5V input supply and consumes only 40µA of
quiescent current when operating and only 3µA in shut-
down. Selectable active-high/active-low control logic
and shutdown control provide additional flexibility. An
autoreset feature latches the switch off in the event of a
short circuit, saving system power. The switch reacti-
vates upon removal of the shorted condition.
The MAX1946 provides several safety features to pro-
tect the USB port. Built-in thermal-overload protection
turns off the switch when the die temperature exceeds
+160°C. Accurate internal current-limiting circuitry pro-
tects the input supply against both overload and short-
circuit conditions. An open-drain fault signal, (FAULT),
notifies the microprocessor (µP) when a thermal over-
load, current-limit, undervoltage lockout (UVLO), or
short-circuit fault occurs. A 20ms fault-blanking feature
enables the circuit to ignore momentary faults, such as
those caused when hot-swapping a capacitive load,
preventing false alarms to the host system. The fault-
blanking feature prevents fault signals from being
issued when the device powers up the load.
The MAX1946 is available in a space-saving 8-pin
(3mm x 3mm) TDFN package and operates over the
extended (-40°C to +85°C) temperature range.
Applications
USB Ports and USB Hubs
Notebook and Desktop Computers
PDAs and Palmtop Computers
Digital Cameras
Docking Stations
Pin Configuration
Features
o Single USB Switch in 3mm x 3mm Package
o Autoreset Feature Saves System Power
o Guaranteed 500mA Load Current
o Built-In 20ms Fault-Blanking Circuitry
o Active-High or Active-Low Control Logic
o Fully Compliant to USB Specifications
o 2.7V to 5.5V Input Voltage Range
o Fault-Indicator Output
o Thermal-Overload Protection
Ordering Information
PART
TEMP RANGE
PIN-
PACKAGE
TOP MARK
MAX1946ETA+ -40°C to +85°C 8 TDFN-EP*
ACQ
+Denotes a lead(Pb)-free/RoHS-compliant package.
*EP = Exposed paddle.
Typical Operating Circuit
TOP VIEW
+
FAULT 1
GND 2
OUT 3
OUT 4
MAX1946
TDFN
8 SEL
7 ON
6 IN
5 IN
INPUT
2.7V TO 5.5V
ACTIVE HIGH
ACTIVE LOW
SELECTABLE
IN
IN
FAULT
ON MAX1946 OUT
SEL
OUT
GND
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.