Data sheet
AS1701, AS1706
1.6W Audio Power Amplifiers
1 General Description
The AS1701 and AS1706 are 1.6W bridged audio power amplifiers
that provide excellent circuit reliability, providing a very low-cost solu-
tion by eliminating external components when used with 2.7 to 5.5V-
powered circuits.
The devices have superb total harmonic distortion (THD) at high-
power output and excellent power supply rejection with 4- and 8Ω-
loads.
Integrated over-temperature and over-current protection circuitry
switch the devices off in case of an output
short-circuit. A digital input allows the devices to automatically switch
into shutdown mode. Click- and pop-suppression circuitry reduces
audible clicks and pops during power-up and shutdown. The gain
(A
V
) of the devices is controlled using external resistors.
The AS1701/AS1706 are available in an 8-pin MSOP package.
2 Key Features
2.7 to 5.5V (V
DD
) Single-Supply Operation
Very High PSRR: Greater Than 65dB @ 217Hz
THD+Noise: 1.6W into 4Ω at 1%
No Output Coupling Capacitors Required
External Gain Configuration Capability
Low-Power Shutdown Mode: 10nA
Click and Pop Suppression
Over-Temperature and Over-Current Protection
Operating Temperature Range: -40 to +85°C
8-pin MSOP Package
3 Applications
The AS1701/AS1706 are ideal as audio front-ends for battery pow-
ered audio devices such as MP3 and CD players, mobile phones,
PDAs, portable DVD players, and any other hand-held battery-pow-
ered device.
Figure 1. Typical Configuration Block Diagram
V
DD
+
10µF
20kΩ
R
F
C
S
6
V
DD
Audio
Input
C
IN
0.33µF
R
IN
20kΩ
4
IN-
3
IN+
–
+
50kΩ
–
40kΩ
5
OUT+
40kΩ
RL =
4 or 8Ω
8
OUT-
2
0.1 to
+
1µF C
B
BIAS
V
DD
/2
+
Av = -1
1
SHDN
Bias
50kΩ
AS1701/
AS1706
7
GND
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AS1701, AS1706
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignment - 8-pin MSOP (Top View)
SHDN 1
8 OUT-
BIAS 2
AS1701/
AS1706
7 GND
IN+ 3
6 VDD
IN- 4
5 OUT+
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
1
2
3
4
5
6
7
8
Pin Name
SHDN
BIAS
IN+
IN-
OUT+
VDD
GND
OUT-
Description
Shutdown.
Connect this pin to GND for the AS1701 (active-high); connect this pin to V
DD
for the
AS1706 (active-low).
DC Bias Bypass
Non-Inverting Input
Inverting Input
Positive Differential Output
Power Supply
Ground
Negative Differential Output
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AS1701, AS1706
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 2
may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in
Electrical Characteristics on page 4
is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Electrical Parameters
Supply Voltage (V
DD
to V
SS
)
Supply Voltage (All Other Pins)
Input Current (latch-up immunity)
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Continuous Power Dissipation
Storage Temperature Range
Junction Temperature
-65
362
+150
+150
mW
ºC
ºC
The reflow peak soldering temperature (body
temperature) specified is in accordance with
IPC/
JEDEC J-STD-020 “Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State Surface
Mount Devices”.
The lead finish for Pb-free leaded packages is matte tin
(100% Sn).
Represents a max. floor life time of unlimited
T
AMB
= 70ºC,
Derate 4.5mW/ºC Above +70ºC
1
kV
Norm: MIL 883 E method 3015
-0.3
V
SS
- 0.3
-100
+7
V
DD
+ 0.3
100
V
V
mA
Norm: JEDEC 78
Min
Max
Units
Comments
Package Body Temperature
+260
ºC
Humidity non-condensing
Moisture Sensitive Level
5
1
85
%
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AS1701, AS1706
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality Control)
methods.
V
DD
= 5V, R
L
=
∞
, C
BIAS
= 0.1µF to GND, SHDN = GND, T
AMB
+25ºC (unless otherwise specified).
Table 3. DC Electrical Characteristics – 5V Operation
Parameter
Operating Temperature Range
Supply Voltage Range
Supply Current
Shutdown Supply Current
SHDN Threshold
V
IL
Common-Mode Bias Voltage
Output Offset Voltage
Power Supply Rejection Ratio
Output Power
3
2
VBIAS
5V Operation
Symbol
T
AMB
V
DD
I
DD
I
SHDN
Conditions
Inferred from PSRR Test
T
AMB
= -40 to +85ºC
SHDN = V
DD
V
IH
Min
-45
2.7
Typ
Max
+85
5.5
10.4
1
Units
°C
V
mA
µA
V
1
6.8
0.01
V
DD
x
0.7
V
OS
PSRR
P
OUT
THD+N
Av = 2, IN- = OUT+, IN- =
BIAS
Inputs Grounded, V
RIPPLE
= 200mVp-p,
R
L
= 4Ω, V
IN-
=
V
IN+
=
V
BIAS
217Hz
1kHz
Total Harmonic Distortion+Noise
Thermal-Shutdown Threshold
Thermal-Shutdown Hysteresis
Power-Up/Enable from Shutdown
Time
Shutdown Time
Turn-Off Transient
R
L
= 4Ω, THD+N = 1%, f
IN
= 1kHz
R
L
= 8Ω, THD+N = 1%, f
IN
= 1kHz
A
V
= 2, R
L
= 4Ω, f
IN
= 1kHz, P
OUT
= 1.3W
A
V
= 2, R
L
= 8Ω, f
IN
= 1kHz, P
OUT
= 1W
V
DD
x
0.3
V
DD
/2 V
DD
/2 V
DD
/2
- 5%
+ 5%
±1
±10
65
63
1.6
0.8
1.2
0.09
0.05
145
9
150
1
20
V
mV
dB
W
%
ºC
ºC
ms
µs
mV
t
PU
t
SHDN
V
POP
1. Quiescent power supply current is specified and tested without loads on the outputs. Quiescent power supply current depends on the
offset voltage when a practical load is connected to the device.
2. Common-mode bias voltage is the voltage on pin BIAS and is nominally V
DD
/2.
3. Guaranteed by design.
3V Operation
V
DD
= 3V, R
L
=
∞
, C
BIAS
= 0.1µF to GND, SHDN = GND, T
AMB
+25ºC (unless otherwise specified).
Table 4. DC Electrical Characteristics – 3V Operation
Parameter
Supply Current
Shutdown Supply Current
Output Power
2
1
Symbol
I
DD
I
SHDN
P
OUT
PSRR
THD+N
Conditions
T
AMB
= -40 to +85ºC
SHDN = V
DD
R
L
= 4Ω, THD+N = 1%, f
IN
= 1kHz
R
L
= 8Ω, THD+N = 1%, f
IN
= 1kHz
217Hz
V
RIPPLE
= 200mVp-p,
R
L
= 8Ω, V
IN-
=
V
IN+
=
V
BIAS
1kHz
A
V
= 2, R
L
= 4Ω, f
IN
= 1kHz, P
OUT
= 500mW
A
V
= 2, R
L
= 8Ω, f
IN
= 1kHz, P
OUT
= 350mW
Min
Typ
6
0.01
0.6
0.4
65
63
0.09
0.06
Max
10
1
Units
mA
µA
W
dB
%
Power Supply Rejection Ratio
Total Harmonic Distortion +Noise
1. Quiescent power supply current is specified and tested without loads on the outputs. Quiescent power supply current depends on the
offset voltage when a practical load is connected to the device.
2. Guaranteed by design.
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AS1701, AS1706
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
Figure 3. THD + Noise vs. Output Power;
V
DD
= 3V, R
L
= 4Ω, Av = 2V
DD
= 3V, R
L
= 8Ω, Av = 2
100
Figure 4. THD + Noise vs. Output Power;
100
10
f
IN
= 1kHz
10
f
IN
= 1kHz
1
f
IN
= 10kHz
THD+N (%)
THD+N (%)
1
f
IN
= 10kHz
0.1
f
IN
= 100Hz
0.1
0.01
0.01
f
IN
= 100Hz
0.001
0
100 200 300 400 500 600 700 800
0.001
0
100
200
300
400
500
600
Output Power (mW)
Figure 5. THD + Noise vs. Output Power;
V
DD
= 3V, R
L
= 4Ω, Av = 4V
DD
= 3V, R
L
= 8Ω, Av = 4
100
Output Power (mW)
Figure 6. THD + Noise vs. Output Power;
100
10
fIN = 1kHz
10
f
IN
= 1kHz
THD+N (%)
THD+N (%)
1
f
IN
= 10kHz
1
f
IN
= 10kHz
0.1
f
IN
= 100Hz
0.1
f
IN
= 100Hz
0.01
0.01
0.001
0
100 200 300 400 500 600 700 800
0.001
0
100
200
300
400
500
600
Output Power (mW)
Figure 7. THD + Noise vs. Output Power;
V
DD
= 5V, R
L
= 4Ω, Av = 2V
DD
= 5V, R
L
= 8Ω, Av = 2
100
Output Power (mW)
Figure 8. THD + Noise vs. Output Power;
100
10
f
IN
= 1kHz
10
f
IN
= 1kHz
THD+N (%)
THD+N (%)
1
f
IN
= 10kHz
1
f
IN
= 10kHz
0.1
f
IN
= 100Hz
0.1
0.01
0.01
f
IN
= 100Hz
0.001
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 2.2 2.4
0.001
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Output Power (W)
Output Power (mW)
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