AS1324

1.5MHz, 600mA, DC/DC Step-Down Regulator

Dat a Sh eet

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

!

Shutdown Mode Supply 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

10µF

10µF

GND

2

4.7µH

1

EN

5

VOUT

4

VIN

3

SW

5 VOUT

AS1324-

18

4 VIN

2

GND

3

SW

1

EN