AS1702 - AS1705
1.8W Single-Channel Audio Power Amplifiers
www.austriamicrosystems.com/Audio/Amps/AS1702-05 Revision 1.48 1 - 20
Datasheet
1 General Description
The AS1702 - AS1705 are single-channel differential audio power-
amplifiers designed to drive 4 and 8Ω loads. The integrated gain cir-
cuitry 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 4Ω 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 dif-
ferent gain levels as shown in Table 1.
Integrated shutdown circuitry disables the bias generator and ampli-
fiers, and reduces quiescent current consumption to less than
100nA. The shutdown input can be set active-high or active-low. All
devices contain click-and-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
2.7V to 5.5V (VCC) Single-Supply Operation
THD+N: 1.8W into 4Ω 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, porta-
ble 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 A
V = 3dB
AS1705 AV = 6dB
AS1702/AS1703/
AS1704/AS1705
Single Supply
2.7V to 5.5V
RL = 4 or 8Ω
+
–
4
IN+
10
OUT+
2
IN-
1
SHDN
3
SHDM
6
OUT-
9
VCC
7
GND
