Data Sheet
AS1324
1.5MHz, 600mA, DC/DC Step-Down Regulator
1 General Description
2 Key Features
ꢀ High Efficiency: Up to 96%
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.
ꢀ 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
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.
Table 1. Standard Versions
Model
Output Voltage
Adjustable via External Resistors
Fixed: 1.2V
AS1324-AD
AS1324-12
AS1324-15
AS1324-18
ꢀ Shutdown Mode Supply Current: ≤1µA
ꢀ Thermal Protection
Fixed: 1.5V
Fixed: 1.8V
ꢀ 5-pin TSOT-23 Package
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.
3 Applications
Very low output voltages can be delivered with the inter-
nal 0.6V feedback reference voltage.
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.
The AS1324 is available in a 5-pin TSOT-23 package.
Figure 1. Typical Application Diagram – High Efficiency Step Down Converter
4.7µH
VOUT = 1.8V, 600mA
VIN = 2.7V to 5.5V
4
3
EN
1
5 VOUT
VIN
SW
CIN
10µF
COUT
10µF
AS1324-
18
AS1324-
18
GND 2
SW 3
5
1
VOUT
EN
4 VIN
GND
2
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