AIC1729
400mA Low Dropout Linear Regulator with
Voltage Detector Function

Analog Integrations Corporation 4F, 9 Industry E. 9th Rd, Science-Based Industrial Park, Hsinchu, Taiwan DS-1729-04 032102
TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1



n FEATURES
l Including MOSFET for VOUT1, LDO for VOUT2,
voltage detector, and shutdown control
l Low Dropout Voltage of 550mV(Typ.) at 400mA
Output Current (VOUT2).
l Guaranteed 700mA Output Current for VOUT1
and 400mA for VOUT2.
l Low Ground Current at 120µA.
l 2% Accuracy Output Voltage of VOUT2.
l Current Limit Function.
l Built in Voltage Detector
l Shutdown Control for VOUT1 and VOUT2

n APPLICATIONS
l Voltage Regulator for DVD-ROM and CD-ROM
Drivers.
l Voltage Regulator for HDD and Floppy Drivers.
l Voltage Regulator for circuits with Stepping
Motor or Servo Motor.







n DESCRIPTION
The AIC1729 is a low dropout linear regulator
with voltage detection function.
It can be divided into 4 main function blocks,
including MOSFET for VOUT1, LDO for
VOUT2 ,voltage detector, and two shutdown
controls.
Voltage detector can be use to detect Vcc.
The detecting voltage of the voltage detector
is from 3.0V to 4.6V with 0.1V step. And the
output (DOUT) of detecting voltage for Vcc
with delay time adjustment function to indicate
VCC low. User only adds one external
capacitor to finish it. When VCC pin is under
the set detection voltage. DOUT pin is logic
low.
VOUT1 is controlled by SD1 pin. When SD1 is
logic high, the internal MOSFET for VOUT1 will
be switched off, vice versa.
The LDO output voltage (VOUT2) is from 1.8V
to 4.0V with 0.1V step for different application.
It is also controlled by SD2 pin. When SD2 is
logic high, the internal LDO for VOUT2 will be
shutdown, vice versa.
The superior characteristics of the AIC1729
include very low dropout voltage, and 2%
accuracy output voltage. Typical ground
current remains 120 µ A, from no load to
maximum loading conditions. Dropout voltage
of VOUT2 is 550mV at 400mA output current.
Output current limiting is provided at VOUT1
and VOUT2.
AIC1729 comes in the popular SO8 package.