
                                           AT1605 
High-Side Power Switch IC 
General Description 
7F, No.9, PARK AVENUE II, Science-Based Industrial Park, Hsinchu 300, Taiwan, R.O.C.                       
Tel: 886-3-563-0878      Fax: 886-3-563-0879            WWW: 
http://www.aimtron.com.tw
4/26/2006 REV:1.1                                        Email: 
service@aimtron.com.tw
1 
Features 
 Operating Voltage:1.8V to 5.5V 
 Built-in N-MOS, 100m
(typ) R
DS,ON
 Quiescent Current: 60μA(typ) 
 Shutdown Current <1μA 
 Built-in Current Limit 
 Built-in Soft-Start. 
 Built-in Under Voltage Lock Function 
 Built-in Thermal Protection 
 TTL Control Input 
 SOT-23-5 Package 
Applications 
 USB Power Measurement 
 Notebook computers 
 Battery-Charger Circuits 
 Hot Plug-in Power Supplies 
The AT1605 is a smart high-side power switch to 
be able to supply up 2.0A from input source. The 
device features preventable reverse current flow 
from OUT to Input by free of parasitic body diode, 
when output voltage exceeds the input voltage, the 
N-MOS is turned off. The AT1605 includes 
built-in low on-resistance of NMOS to saved 
conductive loss, charge pump circuitry to drive 
N-MOS, built-in current limit, soft-start, thermal 
protection and under voltage lock function.
Operating voltage range between 1.8V and 5.5V
supports one Li-lon or adaptor source.  
The device is ideal for notebook computer, 
self-powered and bus powered USB application. 
The low quiescent current is conducive to saved 
power consumption. The AT1605 is available in 
5-pin SOT-23-5 packages. 
Block Diagram
VIN
Clock
Control 
Logic
EN
N- MOS
+
-
BandGap
Reference
UVLO
Current 
Limit
VOUT
GND
Thermal
Protection
Charge pump
Aimtron reserves the right without notice to change this circuitry and specifications.