1.8W Differential Audio Amplifier, Mono, Adjustable Gain0 pages

AS1702 - AS1705
1.8W Single-Channel Audio Power Amplifiers
Data Sheet
www.austriamicrosystems.com Revision 1.47 1 - 20
1 General Description
The AS1702 - AS1705 are single-channel differential
audio power-amplifiers designed to drive 4 and 8Ù
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 high-fidelity audio power amplification.
The devices deliver 1.8W continuous average power per
channel to a 4Ù load with less than 1% total harmonic
distortion (plus noise), while operating from a single 2.7
to 5V supply.
For reduced component designs, the devices are available
with different gain levels as shown in Table 1.
Integrated shutdown circuitry disables the bias generator
and amplifiers, and reduces quiescent current consumption
to less than 100nA. The shutdown input can
be set active-high or active-low. All devices contain clickand-
pop suppression circuitry that reduces audible
clicks and pops during power-up and shutdown.
The AS1702 - AS1705 are pin compatible with the
LM4895 and the MAX9718A/B/C/D. The devices are
available in a 10-pin MSOP package and a 10-pin DFN
package.
Figure 1. Simplified Block Diagram
2 Key Features
! 2.7 to 5.5V (VCC) Single-Supply Operation
! THD+N: 1.8W into 4Ù 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 to National Semiconductor LM4895
(AS1705) and Maxim MAX9718A/B/C/D
! Operating Temperature Range: -40 to +85ºC
! Package Types
- 10-pin MSOP
- 10-pin DFN
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.
Table 1. Standard Products
Model Gain
AS1702 Adjustable (via external components)
AS1703 AV = 0dB
AS1704 AV = 3dB
AS1705 AV = 6dB
AS1702/AS1703/
AS1704/AS1705
Single Supply 2.7
to 5.5V
RL = 4 or 8Ù
+
–
4
IN+
10
OUT+
2
IN-
1
SHDN
3
SHDM
6
OUT-
9
VCC
7
GND