MAX1838_10 Datasheet, PDF (1/13 Pages) Maxim Integrated Products – Dual USB Switch with Fault Blanking and Autoreset

19-2033; Rev 1; 2/10
Dual USB Switch with Fault Blanking
and Autoreset
General Description
The MAX1838 is a dual, current-limited USB switch with
auxiliary input supply. Each switch meets all IEC speci-
fications for USB ports and is guaranteed to supply
500mA from either of two input supplies. A control pin
selects the power source from either the main or auxil-
iary supply.
The MAX1838 has multiple protection features, includ-
ing independent thermal-shutdown on each channel to
limit junction temperature in case of a prolonged short
or overload condition. The device has accurate internal
current-limit and reverse-current protection to safe-
guard the input supply against overload. When pow-
ered from the auxiliary supply, the current limit on each
channel is set independently with an external resistor.
An autoreset feature latches the switch off if the output
is shorted, thereby saving system power. When the
short is removed, the switch automatically turns back
on. Independent fault signals (FAULTA and FAULTB)
notify the microprocessor (µP) that the internal current
limit has been reached. A 20ms fault-blanking feature
prevents the MAX1838 from issuing false alarms to the
host during power-up or when hot-swapping into a
capacitive load.
The MAX1838 is available in a space-saving 16-pin
QSOP. For other USB current-limited switches, refer to
the MAX1693, MAX1694, MAX1812, and MAX1823.
Applications
Desktops
Notebook Computers
USB Ports
Docking Stations
Pin Configuration
TOP VIEW
GND 1
SEL 2
AUXA 3
INA 4
INB 5
AUXB 6
ON 7
GND 8
MAX1838
16 FAULTA
15 ADJA
14 OUTA2
13 OUTA1
12 OUTB2
11 OUTB1
10 ADJB
9 FAULTB
Features
o Dual USB Switch with Auxiliary Input
o Autoreset from Fault Condition
o Guaranteed 500mA Load per Channel
o Programmable Current Limits on Auxiliary Inputs
o Reverse Current Protection
o Thermal Overload Protection
o Built-In 20ms Fault-Blanking
o 4V to 5.5V Range
o Independent FAULT Indicator Outputs
PART
MAX1838EEE
Ordering Information
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
16 QSOP
Typical Operating Circuit
AUX
AUXA
AUXB
FAULTB
FAULTA
IN
INA
MAX1838
OUTB
INB
OUTB
10µF
OUTA
SEL
OUTA
ON
ADJB
ADJA
GND
QSOP
________________________________________________________________ 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.