AS1324
1.5MHz, 600mA, DC/DC Step-Down Regulator
Data Sheet
www.austriamicrosystems.com Revision 1.03 1 - 20
1 General Description
The AS1324 is a high-efficiency, constant-frequency
synchronous buck converter available in adjustable- and
fixed-voltage versions. The wide input voltage range
(2.7V to 5.5V), automatic powersave mode and minimal
external component requirements make the AS1324
perfect for any single Li-Ion battery-powered application.
Typical supply current with no load is 30µA and
decreases to ≤1µA in shutdown mode.
The AS1324 is available as the standard versions listed
in Table 1.
An internal synchronous switch increases efficiency and
eliminates the need for an external Schottky diode. The
internally fixed switching frequency (1.5MHz) allows for
the use of small surface mount external components.
Very low output voltages can be delivered with the inter-
nal 0.6V feedback reference voltage.
The AS1324 is available in a 5-pin TSOT-23 package.
2 Key Features
! High Efficiency: Up to 96%
! Output Current: 600mA
! Input Voltage Range: 2.7V to 5.5V
! Constant Frequency Operation: 1.5MHz
! Variable- and Fixed-Output Voltages
! No Schottky Diode Required
! Automatic Powersave Operation
! Low Quiescent Current: 30µA
! Internal Reference: 0.6V
! Shutdo w n Mo de Sup p l y Current: ≤1µA
! Thermal Protection
! 5-pin TSOT-23 Package
3 Applications
The device is ideal for mobile communication devices,
laptops and PDAs, ultra-low-power systems, threshold
detectors/discriminators, telemetry and remote systems,
medical instruments, or any other space-limited applica-
tion with low power-consumption requirements.
Table 1. Standard Versions
Model Output Voltage
AS1324-AD Adjustable via External Resistors
AS1324-12 Fixed: 1.2V
AS1324-15 Fixed: 1.5V
AS1324-18 Fixed: 1.8V
Figure 1. Typical Application Diagram – High Efficiency Step Down Converter
AS1324-
18
COUT
10µF
CIN
10µF
GND
2
V
IN = 2.7V to 5.5V
V
OUT = 1.8V, 600mA
4.7µH
1
EN
5
VOUT
4
VIN
3
SW
5
VOUT
AS1324-
18
4
VIN
2
GND
3
SW
1
EN
