Stereo 2.8W Audio Power Amplifier with DC Volume Control
and Selectable Gain
Copyright
ANPEC Electronics Corp.
Rev. A.
1 -
Apr
.,
2003
APA4838
www.anpec.com.tw
1
ANPEC reserves the right to make changes to improve reliability or manufacturability without notice, and advise
customers to obtain the latest version of relevant information to verify before placing orders.
Operating Voltage : 4.5V to 5V
Stereo switchable bridged/single-ended
power amplifiers
DC Volume Control Interface , 0dB to 78dB
with precision scale
Supply Current , I
DD
= 15mA at Stereo BTL
Low Shutdown Current , I
DD
= 0.7A
Bridge-Tied Load (BTL) or Single-Ended-(SE)
Modes Operation
Output Power at 1% THD+N , V
DD
=5V
2.3W/Ch (typ) into a 3
Load
2.0W/Ch (typ) into a 4
Load
1.2W/Ch (typ) into a 8
Load
Output Power at 10% THD+N , V
DD
=5V
2.8W/Ch (typ) into a 3
Load
2.3W/Ch (typ) into a 4
Load
1.5W/Ch (typ) into a 8
Load
Single-ended mode at 1.0% THD+N
95mW/Ch (typ) into 32
Load
Depop Circuitry Integrated
Thermal shutdown protection and over current
protection circuitry
High supply voltage ripple rejection
PC99 Compliant
28-pin TSSOP-P (with enhanced thermal pad)
power package available
Features
General Description
Applications
Pin Description
Notebook and Desktop Computers
Multimedia Monitors
Portable Applications
The APA4838 is a monolithic integrated circuit , which
provides DC volume control , and a stereo bridged
audio power amplifiers capable of producing 2.8W
(2.3W) into 3
with less than 10% (1.0%) THD+N.
APA4838 includes a DC volume control , stereo
bridge-tied and single-ended audio power amplifiers
, stereo docking outputs , and a selectable gain con-
trol , that makes it optimally fittable for notebook PC
, multimedia monitors , and other portable
applications. The attenuator range of the volume
control in APA4838 is from 0dB (DC_Vol=0.8V
DD
) to
78dB (DC_Vol=0V) with 31 steps. Both of the depop
circuitry and the thermal shutdown protection circuitry
are integrated in APA4838 , that reduces pops and
clicks noise during power up or shutdown mode op-
eration , and protects the chip from being destroyed
by over temperature failure. To simplify the audio
system design , APA4838 combines a stereo bridge-
tied loads (BTL) mode for speaker drive and a stereo
single-end (SE) mode for headphone drive into a
single chip , where both modes are easily switched
by the HP Sense input control pin signal. Besides
the low supply current design to increase the effi-
ciency of the amplifiers , APA4838 also features a
shutdown function which keeps the supply current
only 0.7A (typ).
Shutdown
GND
V
D D
GND
HP Sense
BY PA SS
Right Dock
Gain Select
M ode
M ute
DC V ol
Right In
Beep In
Left In
Left Dock
GND
10
1
2
3
4
5
6
7
8
9
11
12
13
14
Right Out +
V
D D
Right Out -
Right Gain 2
Right Gain 1
GND
Left Gain 1
Left Gain 2
Left Out -
GND
V
D D
Left Out +
28
27
26
25
24
23
22
21
20
19
18
17
16
15
Copyright
ANPEC Electronics Corp.
Rev. A.
1 -
Apr
.,
2003
APA4838
www.anpec.com.tw
2
Block Diagram
Ordering and Marking Information
P a c k a g e C o d e
R : T S S O P -P
T e m p . R a n g e
I : -4 0 to 8 5 C
H a n d lin g C o d e
T U : T u b e T R : T a p e & R e e l
A P A 4 8 3 8
H a n d lin g C o d e
T e m p . R a n g e
P a c k a g e C o d e
A P A 4 8 3 8 R :
A P A 4 8 3 8
X X X X X
X X X X X - D a te C o d e
Mode
Control
Mode
Mute
HP Sense
Volume
Control
31 steps
Beep
Detect
-
+
-
+
Power
Management
Click and Pop
Suppression
Circuitry
-
+
-
+
-
+
Gain Select
Left Dock
20K
20K
20K
10K
10K
- Left Out
20K
20K
+ Right Out
- Right Out
0.068
F
20K
10K
20K
20K
10K
0.068
F
20K
20K
Right Dock
Shutdown
V
DD
GND
Bypass
Bias
Left In
0.33
F
Right In
0.33
F
20K
200K
200K
20K
Beep In
+ Left Out
-
+
DC_Vol
20K
20K
Bias
L
e
ft G
a
in
1
L
e
ft G
a
in
2
Ri
g
h
t
Ga
i
n
1
Ri
g
h
t
Ga
i
n
2
Left
Audio Input
Right
Audio Input
Copyright
ANPEC Electronics Corp.
Rev. A.
1 -
Apr
.,
2003
APA4838
www.anpec.com.tw
3
Symbol
Parameter
Rating
Unit
V
DD
Supply Voltage
-0.3 to 6
V
V
IN
Input Voltage Range, HP sense, Shutdown,
Mute, Mode, Gain Select
-0.3 to V
DD
+0.3
V
T
A
Operating Ambient Temperature Range
-40 to 85
C
T
J
Maximum Junction Temperature
Internally Limited*
1
C
T
STG
Storage Temperature Range
-65 to +150
C
T
S
Soldering Temperature,10 seconds
260
C
V
ESD
Electrostatic Discharge
-2000 to 2000*
2
V
P
D
Power Dissipation
Internally Limited
W
Note:
1.APA4838 integrated internal thermal shutdown protection when junction temperature ramp up to 150C
2.Human body model: C=100pF, R=1500
, 3 positives pulse plus 3 negative pulses
3.Machine model: C=200pF, L=0.5
F, 3 positive pulses plus 3 negative pulses
Recommended Operating Conditions
Min.
Max.
Unit
Supply Voltage, V
DD
4.5
5.5
V
Shutdown, Mute, Mode, Gain Select
2
High level threshold voltage, V
IH
HP Sense
4
V
Shutdown, Mute, Mode, Gain Select
1.0
Low level threshold voltage, V
IL
HP Sense
3
V
Common mode input voltage, V
ICM
V
DD
-1.0
V
Thermal Characteristics
Symbol
Parameter
Value
Unit
R
THJA
Thermal Resistance from Junction to Ambient in Free Air
TSSOP-P*
45
K/W
* 5 in
2
printed circuit board with 2oz trace and copper pad through 9 25mil diameter vias.
The thermal pad on the TSSOP_P package with solder on the printed circuit board.
(Over operating free-air temperature range unless otherwise noted.)
Absolute Maximum Ratings
Copyright
ANPEC Electronics Corp.
Rev. A.
1 -
Apr
.,
2003
APA4838
www.anpec.com.tw
4
Electrical Characteristics
Electrical Characteristics for Volume Attenuators
The following specifications apply for V
DD
= 5V. Limits apply for T
A
= 25C
Electrical Characteristics for BTL Mode Operation
The following specifications apply for V
DD
= 5V unless otherwise noted. Limits apply for T
A
= 25C
APA4838
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
Gain with V
PIN 7
=5V
0.5
C
RANGE
Attenuator Range
Attenuation with V
PIN 7
=0V
-65
-78
dB
V
PIN 5
=5V, Bridged Mode
-70
A
M
Mute Attenuation
V
PIN 5
=5V, Single-Ended Mode
-70
dB
APA4838
Symbol
Parameter
Test Conditions
Typ.
Unit
V
OS
Output Offset Voltage
V
IN
=0V
5
mV
THD=1%, f=1kHz
R
L
=3
R
L
=4
R
L
=8
2.3
2.0
1.2
P
O
Output Power
THD=10%, f=1kHz
R
L
=8
1.5
W
THD+N
Total Harmonic Distortion + Noise A
VD
=2, f=1kHz
R
L
=4
, P
O
=1.5W
R
L
=8
, P
O
=1W
0.07
0.07
%
PSRR
Power Supply Rejection Ratio
V
RIPPLE
=100mV
Rms
C
B
=2.2
F,
R
L
=8
, f=1kHz
70
dB
X
TALK
Channel Separation
C
B
=2.2
F, f=1kHz, R
L
=8
90
dB
SNR
Signal-to-Noise Ratio
V
DD
=5V, P
O
=1.1W, R
L
=8
,A-Wtd
Filter
95
dB
V
N
Output Noise Voltage
R
L
=8
,A-Wtd Filter
30
V
Electrical Characteristics for Entire IC
The following specifications apply for V
DD
= 5V unless otherwise noted. Limits apply for T
A
= 25C
APA4838
Symbol
Parameter
Test Conditions
Min.
Typ.
Max.
Unit
V
DD
Supply Voltage
4.5
5.5
V
I
DD
Quiescent Power Supply
Current
V
IN
=0V, I
O
=0A
15
25
mA
I
SD
Shutdown Current
V
PIN 2
= V
DD
0.7
2.0
A
Copyright
ANPEC Electronics Corp.
Rev. A.
1 -
Apr
.,
2003
APA4838
www.anpec.com.tw
5
APA4838
Symbol
Parameter
Test Conditions
Typ.
Unit
V
OS
Output Offset Voltage
V
IN
=0V
5
mV
THD=1%,
f=1kHz, R
L
=32
95
P
O
Output Power
THD=10%,
f=1kHz, R
L
=32
110
mW
A
V
= 1 , V
OUT
=1V
RMS
, R
L
=10k
, f=1kHz
0.05
%
THD+N
Total Harmonic Distortion
plus Noise
P
O
=75mW, R
L
=32
, A
V
= 1, f=1kHz
0.07
%
PSRR
Power Supply Rejection
Ratio
V
RIPPLE
=100mV
RMS
, f=120Hz, C
B
=2.2
F
52
dB
X
TALK
Channel Separation
C
B
=2.2
F, R
L
=8
, f=1kHz
90
dB
SNR
Signal-to-Noise Ratio
P
O
=75mW, R
L
=32
, A-Wtd Filter
102
dB
V
N
Output Noise Voltage
R
L
=32
, A-Wtd Filter
20
V
Electrical Characteristics (Cont.)
Electrical Characteristics for SE Mode Operation (Cont.)
The following specifications apply for V
DD
= 5V unless otherwise noted. Limits apply for T
A
= 25C
Pin Description
Pin
Name
No
I/O
Description
GND
1, 8, 14,
20, 23
Ground connection for circuitry.
Shutdown
2
I Shutdown mode control signal input, place entire IC in shutdown mode when
held high, Idd=0.7uA
Gain Select
3
I Gain select input pin, logic high will switch the amplifier to external gain
mode, and logic low will switch to internal unity gain.
Mode
4
I Mode select input pin, fixed gain when logic L and gain adjustable mode
when logic H.
Mute
5
I Mute control input pin, active H.
V
DD
6, 16, 27
Supply voltage input pin
DC_Vol
7
I Volume control function input pin.
Right Dock
9
O Right docking output pin
Right In
10
I Right channel audio input pin
Beep In
11
I Beep signal input pin
Left In
12
I Left channel audio input pin
Left Dock
13
O Right docking output pin
Left Out +
15
O Left channel positive output pin
Left Out -
17
O Left channel negative output pin
Left Gain 2
18
Connect pin 2 of the external gain setting resistor for left channel
Left Gain 1
19
Connect pin 1 of the external gain setting resistor for left channel
HP Sense
21
I Headphone sense control pin
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