AS1335

1.5A, 1.5MHz, Synchronous DC/DC Step-Down Converter

www.austriamicrosystems.com/DC-DC_Step-Down/AS1335

Revision 1.03

1 - 18

Data sheet

1 General Description

The AS1335 is a high-efficiency, constant-frequency

synchronous buck converter available in a fixed or an

adjustable output voltage version. The wide input volt-

age range (2.6V to 5.25V), the high output current (up to

1.5A) and minimal external component requirements

make the AS1335 perfect for any single Li-Ion battery-

powered application.

Typical supply current with no load is 400µA and

decreases to

≤1µA in shutdown mode. The highly effi-

cient duty cycle (100%) provides low dropout operation,

prolonging battery life in portable systems.

The device also offers a power-ok signal with a 215ms

delay, which can be reseted or delayed further via the

RSI pin.

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.

The AS1335 is available in a 10-pin TDFN 3x3mm pack-

age.

Figure 1. AS1335 - Typical Application Diagram

2 Key Features

!

High Efficiency: Up to 96%

!

Output Current: 1.5A

!

Input Voltage Range: 2.6V to 5.25V

!

!

Constant Frequency Operation: 1.5MHz

!

No Schottky Diode Required

!

Power OK with 215ms delay

!

Low Dropout Operation: 100% Duty Cycle

!

Low Quiescent Supply Current: 400µA

!

Shutdown Mode Supply Current:

≤1µA

!

Current Mode Operation for Excellent Line/Load

Transient Response

!

Thermal Protection

!

10-pin TDFN 3x3mm 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.

AS1335

22µF

22µF

2.6V to 5.25V

1.0V, 1.5A

2.2µH

NC

GND

VIN

SW

POK

FB

EN

GND

PGND

RSI