AS1702, AS1703, AS1704, AS1705

1.6W Single-Channel Audio Power Amplifiers

Dat a Sh eet

www.austriamicrosystems.com

Revision 1.01

1 - 13

1 General Description

The AS1702, AS1703, AS1704, and AS1705 are single-

channel differential audio power-amplifiers designed to

drive 4 and 8

Ω loads. The integrated gain circuitry of

these amplifiers and their small size make them ideal for

2.7- to 5V-powered portable audio devices.

The differential input design improves noise rejection

and provides common-mode rejection. A bridge-tied

load (BTL) design minimizes external component count,

while providing Hi-Fi audio power amplification.

The devices deliver 1.6W continuous average power per

channel to a 4

Ω load with less than 1% total harmonic

distortion (plus noise), while operating from a single 2.7

to 5V supply.

In order to facilitate reduced component designs, the

devices are available with different gain levels:

!

AS1702 – Adjustable Gain (via external components)

!

!

!

Integrated shutdown circuitry disables the bias genera-

tor and amplifiers, and reduces quiescent current con-

sumption to less than 100nA. The shutdown input can

be set as active-high or active-low. All devices contain

comprehensive click-and-pop suppression circuitry that

reduces audible clicks and pops during power-up and

shutdown.

The AS1702, AS1703, AS1704, and AS1705 are pin

compatible with the LM4895 and the MAX9718A/B/C/D.

The devices are available in a 10-pin MSOP package.

Figure 1. Simplified Block Diagram

2 Key Features

!

!

THD+N: 1.6W into 4

Ω at 1% (per Channel)

!

Differential Input

!

Adjustable Gain Option (AS1702)

!

Internal Fixed Gain to Reduce External Component

Count (AS1703, AS1704, AS1705)

!

<100nA Low-Power Shutdown Mode

!

Click and Pop Suppression

!

Pin-Compatible National Semiconductor LM4895

(AS1705) and Maxim MAX9718A/B/C/D

!

Operating Temperature Range: -40 to +85°C

!

Low-Cost MSOP-10 Package

3 Applications

The devices are ideal as audio front-ends for battery

powered audio devices such as MP3 and CD players,

mobile phones, PDAs, portable DVD players, and any

other hand-held battery-powered device.

AS1702, AS1703,

AS1704, AS1705

OUT+

Single Supply

2.7 to 5.5V

SHDN

IN+

IN-

OUT-

SHDM

4 or 8

Ω

+

–

GND