AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
1
FEATURES
New generation charge pump technology
K-Chargepumpefficiency reaches as high as
92%
Power amplifier overall efficiency 75%greatly
prolong mobile phone usage time
Ultra-low distortion0.02%
Within Lithium battery voltage range, output
power is maintained constant
Output Power level0.8W1W1.2W
Second generation Non-crack-noise (NCN)
technology
Super TDD-Noise suppression
Ultra-low EMI
One wire pulse control
High PSRR-65dB217Hz
Small 2mm×2mm FC-16package
APPLICATIONS
Smart phone
DESCRIPTION
AW8736 is designed to enhance smart mobile phone
sound quality,which is a new high efficiency, ultra-low
distortion, constant large volume, sixth generation class
K audio amplifiers. Using a new generation of charge
pump technologyK -Chargepump structure, efficiency
as high as 92%, power amplifier’s overall efficiency
reaches 75%, greatly prolong the mobile phone usage
time. 0.02% ultra-low distortion and unique
non-crack-noise (NCN) technology brings high quality
music enjoyment.
AW8736 integrated K-Chargepump booster circuit,
the output power cannot drop along with lithium battery
voltage lower down. Within lithium battery voltage
range(3.3 V - 4.35V), output power is constant, providing
high quality music enjoyment. AW8736 has 0.8 W, 1 W
and 1.2 W three output power level, recommended using
rated power of 0.7W and above speakers, which
greatly improve the volume, and effectively protect
speakers.
The AW8736 uses awinic proprietary TDD-Noise
suppression technology and EMI suppression
technology, effectively restrain TDD-Noise and EMI
interference.
AW8736 built-in over current protection,
over-temperature protection and short circuit protection
function, effectively protect the chip. The AW8736 uses
small 2mmx2mm FC-16 package.
DEVICE PINOUT
AW8736FCR TOP VIEW
INP INN SHDN
GND
PVDD
C2N C2N
C2P C1P
C1N
VDD
VDD
VOP
VON
GND
12 3 4
A
B
C
D
GND
12 3 4
A
B
C
D8736
XXXX
AW8736FCR MARKING
8736 AW8736FCR
XXXXProduction tracking code
Please notice the pin number
Figure 1 AW8736FCR pin diagram top view and device marking
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
2
PIN DESCRIPTION
Number
Description
A1
Positive audio input terminal
A2
Negative audio input terminal
A3B3
Power supply
A4
Chip power down pinactive lowone wire pulse control
B1
Negative side of the external charge pump flying capacitor C2
B2
B4
Positive audio output terminal
C1
Negative side of the external charge pump flying capacitor C1
C2
Ground
C3
C4
D1
Positive side of the external charge pump flying capacitor C2
D2
Positive side of the external charge pump flying capacitor C1
D3
Boost charge pump output voltage
D4
Negative audio output terminal
APPLICATION DIAGRAM
C1P
AW8736
C1N
COUT
4.7uF
PVDD
INP
INN
3KΩ
15nF
3KΩ
15nF
Cin
Cin Rin
Rin
VOP
VON
GND
VDD
SHDN
Pulse Input
12
CF1
2.2uF
CS1
4.7uF
VBAT
3 4
C1
220pF
A4
A2
A1
C2,C3,C4
B4
D4
B1
B2
C2
1nF
C3
1nF
D3
A3,B3 D2 C1 C2P C2N
CF2
2.2uF
B1,B2D1
CS2
0.1uF
Single-Ended
Input
Figure 2 AW8736 single-ended input application diagram (Note 1)
Note1when single-ended inputinput audio signal can arbitrarily connect to one of INNINP input terminal
the other terminal connects to ground through input capacitor and resistance.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
3
Filter capacitor Cs suggest using X7R/X5R ceramic capacitors, if using tantalum capacitors, one ceramic
capacitor greater than 1 uF must be placed near the VDD pin to filter high frequency interference signal.
C1P
AW8736
C1N
COUT
4.7uF
PVDD
INP
INN
3KΩ
15nF
3KΩ
15nF
Cin
Cin Rin
Rin
VOP
VON
GND
VDD
SHDN
Pulse Input
12
CF1
2.2uF
CS1
4.7uF
VBAT
3 4
C1
220pF
A4
A2
A1
C2,C3,C4
B4
D4
B1
B2
C2
1nF
C3
1nF
D3
A3,B3 D2 C1 C2P C2N
CF2
2.2uF
B1,B2D1
CS2
0.1uF
Differential
Input
Figure 3 AW8736 differential input application diagram
ORDERING INFORMATION
Product Type
Operation temperature range
Package
Device Marking
Delivery Form
AW8736FCR
-40℃~85
FC-16
8736
Tape and Reel
3000 pcs
AW8736
Shipment
R: Tape & Reel
Package type
FC: FC16
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
4
ABSOLUTE MAXIMUM RATING(Note2)
Parameter
Range
Supply Voltage VDD
-0.3V to 6V
INPINN Input Pin Voltage
-0.3V to VDD+0.3V
Package Thermal Resistance θJA
69℃/W
Ambient Temperature Range
-40℃ to 85℃
Maximum Junction Temperature TJMAX
125℃
Storage Temperature Range TSTG
-65℃ to 150℃
Lead TemperatureSoldering 10 Seconds
260℃
ESD RatingNote 3
HBMhuman body model
±6KV
Latch-up
Test ConditionJEDEC STANDARD NO.78B DECEMBER 2008
+IT450mA
-IT-450mA
Note 2Stresses beyond those listed under "absolute maximum ratings" may cause permanent damageto the device.
These are stress ratings only and functional operation of the device at these or any other conditions beyond those
indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions
for extended periods may affect device reliability.
Note 3The human body model is a 100pF capacitor discharged through a 1.5kΩ resistor into each pin. Test method:
MIL-STD-883G Method 3015.7
MODE DESCRIPTION
AW8736 audio amplifier outer input capacitor is Cinouter input resist is Rininner input resist is 16.5K
gain Av is 320K/(Rin+16.5K). Recommended typical application is
1 Cin=15nFRin=3KAv=16.3V/V
2 Cin=15nFRin=10KAv=12V/V
Mode
Enable
Signal
GainV/V
NCN PowerW
NCN
function
RL=8
RL=4
MODE1
16.3
12
1.2
2.25
MODE2
16.3
12
1
2
MODE3
16.3
12
0.8
1.6
MODE4
16.3
12
1.65W@THD=1%
2.15W@THD=1%
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
5
ELECTRICAL CHARACTERISTICS
Test conditionTA=25℃(unless otherwise noted
Parameter
Test conditions
Min
Typ
Max
Units
VDD
Power supply voltage
3.0
5.0
V
VIH
SHDN
high input voltage
1.3
VDD
V
VIL
SHDN
low input voltage
0
0.35
V
|VOS|
Output offset voltage
Vin=0VVDD=3.0V to 5.0V
-30
0
30
mV
ISD
Shutdown current
VDD=3.6V
SHDN
=0V
1
μA
TTG
Thermal AGC start
temperature threshold
150
TTGR
Thermal AGC exit temperature
threshold
130
TSD
Over temperature protection
threshold
160
TSDR
Over temperature protection
recovery threshold
130
TON
Start-up time
40
ms
K-Chargepump
PVDD
Output voltage
VDD =3.0V to 3.8V
1.5*
VDD
V
VDD >3.8V
5.8
V
Vhys
OVP hysteresis
VDD >3.8V
50
mV
FCP
Charge Pump frequency
VDD=3.0V to 5.0V
0.8
1.06
1.33
MHz
ηCP
Charge pump efficiency
VDD=4.2V, Iload=200mA
92
%
TST
Soft-start time
No loadCOUT=4.7uF
1
1.2
1.4
ms
IL
Current limit when PVDD short
to ground
350
mA
Class K power amplifiermode1-mode4
Iq
Quiescent current
VDD=3.6VVin=0no load
9.5
mA
η
Efficiency
VDD=4.2VPo=1.2WRL=8Ω
75
%
Fosc
Modulation frequency
VDD=3.0V to 5.0V
600
800
1000
kHz
Av
gain
Outside input resistance=3kΩ
16.3
V/V
Rini
Inner input resistance
16.5
Pncn
Mode1 NCN output power
VDD=4.2VRL=8Ω
1.2
W
VDD=4.2VRL=4Ω
2.25
W
Mode2 NCN output power
VDD=4.2VRL=8Ω
1
W
VDD=4.2VRL=4Ω
2
W
Mode3 NCN output power
VDD=4.2VRL=8Ω
0.8
W
VDD=4.2VRL=4Ω
1.6
W
PSRR
Power supply rejection ratio
VDD=4.2VVp-p_sin=200mV
217Hz
-53
-65
dB
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
6
1kHz
-53
-65
dB
SNR
Signal-to-noise ratio
VDD=4.2VPo=0.8WRL=8Ω
84.5
dB
VDD=4.2VPo=1.65WRL=8Ω
87.5
dB
Vn
Output noise voltage
VDD=4.2Vf=20Hz to 20kHz
input ac grounded
A-weighting
155
uVrms
THD+N
Total harmonic
distortion+noise
VDD=4.2V,Po=1W,RL=8Ω,f=1kHz,Mode1
0.02
%
VDD=4.2V,Po=1.2W,RL=8Ω,f=1kHz,Mode4
0.02
%
PO
Mode4 output power
THD+N=10%f=1kHzRL=8ΩVDD=4.2V
2.0
W
THD+N=1%f=1kHzRL=8ΩVDD=4.2V
1.65
W
THD+N=10%f=1kHzRL=8ΩVDD=3.6V
1.5
W
THD+N=1%f=1kHzRL=8ΩVDD=3.6V
1.23
W
THD+N=10%f=1kHzRL=4ΩVDD=4.2V
2.58
W
THD+N=1%f=1kHzRL=4ΩVDD=4.2V
2.15
W
THD+N=10%f=1kHzRL=4ΩVDD=3.6V
1.85
W
THD+N=1%f=1kHzRL=4ΩVDD=3.6V
1.55
W
One wire pulse control
TH
SHDN
high level duration time
VDD=3.0V to 5.0V
0.75
2
10
us
TL
SHDN
low level duration time
VDD=3.0V to 5.0V
0.75
2
10
us
TLATCH
SHDN
turn on delay time
VDD=3.0V to 5.0V
150
500
us
TOFF
SHDN
turn off delay time
VDD=3.0V to 5.0V
150
500
us
NCNnote 4
TAT
Attack time(-13.5dB)
40
ms
TRL
Release time13.5dB
1.2
s
AMAX
Maximum attenuation
-13.5
dB
Note 4Attack time points to 13.5dB gain attenuation timeRelease time points to 13.5dB gain recovery time.
MEASUREMENT SYSTEM
AW8736 features switching digital output, as shown in Figure 4. Need to connect a low pass filter to
VOP/VON output respectively to filter out switch modulation frequency, then measure the differential
output of filter to obtain ananlog output signal.
VOP
VON
INP
INN
Rin
Cin
K6
Rin
Cin 30kHz
Low-Pass Fliter
500Ω
500Ω
10nF
10nF
Figure 4 AW8736 test setup
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
7
Low pass filter uses resistance and capacitor values listed in Table 2.
Rfilter
Cfilter
Low-pass cutoff frequency
500Ω
10nF
32kHz
1kΩ
4.7nF
34kHz
Table 2 AW8736 recommended values for low pass filter
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
8
TYPICAL CHARACTERISTICS
0
0.2
0.4
0.6
0.8
1.0
1.2
3.3 3.5 3.9 4.3
Supply Voltage ( V )
NCN Output Power( W )
NCN OUTPUT POWER vs SUPPLY VOLTAGE
3.7 4.1
1.4
RL=8Ω+33μH
MODE1
MODE2
MODE3
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Output Power ( W )
Efficiency( % )
AMPLIFIER EFFICIENCY vs OUTPUT POWER
RL=8Ω+33μH
VDD=4.2V
VDD=3.6V
VDD=3.3V
16
24
2
4
6
8
10
12
14
18
20
22
50 100 20K
1K 10K
GAIN vs FREQUENCY
Frequency ( Hz )
Gain( V/V )
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2
Output Power ( W )
Efficiency( % )
K-CHARGEPUMP EFFICIENCY vs OUTPUT POWER
VDD=4.2V
CF1,CF2=2.2μF
COUT=4.7μF
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
1
10
0.1
0.01
THD+N vs FREQUENCY
THD+N (%)
Frequency ( Hz )
50 100 20K1K 10K
MODE1
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
1
10
0.1
0.01
THD+N vs FREQUENCY
THD+N (%)
Frequency ( Hz )
50 100 20K1K 10K
MODE2
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
AW8736 output power remain constant
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
9
Output Power( W )
0.2 1 2
0.5
0.1
10
0.01
THD+N (%)
1
THD+N vs OUTPUT POWER
VDD=3.6V
VDD=4.2V
Mode4
f=1kHz
Cin=1μF
RL=8Ω+33μH
0.1
2OUTPUT POWER vs VIN
Output Power (W)
VIN ( Vp )
0.1 1
0.5
1
0.5 NCN
2
Mode1
VDD=4.2V
f=1kHz
RL=8Ω+33μH
0.1
2
VIN ( Vp )
0.1 1
0.5
1
0.5 NCN
2
Mode2
VDD=4.2V
f=1kHz
RL=8Ω+33μH
0.1
2
0.1 1
0.5
1
0.5
NCN
2
Mode3
VDD=4.2V
f=1kHz
RL=8Ω+33μH
1
10
0.1
0.01
THD+N vs FREQUENCY
THD+N (%)
Frequency ( Hz )
50 100 20K1K 10K
Mode3
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
0
2
4
6
8
10
12
3.3 3.5 3.9 4.3
Supply Voltage ( V )
Quiescent Current(mA )
QUIESCENT CURRENT vs SUPPLY VOLTAGE
3.7 4.1
14
RL=8Ω+33μH
OUTPUT POWER vs VIN
Output Power (W)
OUTPUT POWER vs VIN
Output Power (W)
VIN ( Vp )
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
10
START-UP SEQUENCE
SHDN
VOP&VON
6ms/div
SHUTDOWN SEQUENCE
SHDN
VOP&VON 50μs/div
20 100 20K
1K 10K
-90
-80
-70
-60
-50
-40
-30
PSRR (dB)
VDD=3.6V
VDD=4.2V
-20
-10
0
Mode3
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
20 100 20K
1K 10K
-90
-80
-70
-60
-50
-40
-30
PSRR (dB)
VDD=3.6V
VDD=4.2V
-20
-10
0
Mode4
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
20 100 20K
1K 10K
-90
-80
-70
-60
-50
-40
-30
PSRR (dB)
PSRR vs FREQUENCY
Frequency ( Hz )
VDD=3.6V
VDD=4.2V
-20
-10
0
Mode1
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
20 100 20K
1K 10K
-90
-80
-70
-60
-50
-40
-30
PSRR (dB)
PSRR vs FREQUENCY
Frequency ( Hz )
VDD=3.6V
VDD=4.2V
-20
-10
0
Mode2
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
PSRR vs FREQUENCY PSRR vs FREQUENCY
Frequency ( Hz )
Frequency ( Hz )
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
11
NCN ATTACK TIME
10ms/div
Vin
VOP-VON
NCN RELEASE TIME
Vin
VOP-VON
200ms/div
FUNCTIONAL DIAGRAM
INN
INP
Class-K
Modulator
Ultra Low
EMI
output
stage
SHDN
NCN
GND
OSC
VOP
VON
K-Chargepump
SHDN&BIAS
C1P C2P
PVDD
VDD
INPUT
BUFFER
SEGMENTED
OTP
Noise
Cancellor
C1N C2N
OCP
OVP
Current
Limit
AW8736
Figure 5 AW8736 functional diagram
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
12
OPERATION
AW8736 is designed to enhance smart mobile phone sound quality,which is a new high efficiency,
ultra-low distortion, constant large volume, sixth generation class K audio amplifiers. Using a new
generation of charge pump technologyK -Chargepump structure, built in current limiting control loop and
over-voltage-protection(OVP) loopefficiency as high as 92%, power amplifier’s overall efficiency reaches
75%, greatly prolong the mobile phone usage time. 0.02% of the ultra-low distortion and unique
non-crack-noise (NCN) technology brings high quality music enjoyment.
AW8736 integrated K-Chargepump booster circuit, the output power cannot drop along with lithium
battery voltage lower down. Within lithium battery voltage range(3.3 V - 4.35V), output power is constant,
providing high quality music enjoyment. AW8736 has 0.8 W, 1 W and 1.2 W three output power level,
recommended using rated power of 0.7W and above speakers, which greatly improve the volume, and
effectively protect speakers.
The AW8736 uses awinic proprietary TDD-Noise suppression technology and EMI suppression
technology, effectively restrain TDD-Noise and EMI interference.
AW8736 built-in over current protection, over-temperature protection and short circuit protection
function, effectively protect the chip. The AW8736 uses small 2mmx2mm FC-16 package. The AW8736
is specified over the industrial temperature range of -40 to 85.
CONSTANT OUTPUT POWER
In the mobile phone audio applications, the NCN function to promote music volume and quality is very
attractive, but as the lithium battery voltage drops, general power amplifier output power will reduce
gradually, leads to smaller and smaller music volume. So, it is hard to provide high quality music within
the battery voltage range. The AW8736 uses unique second generation NCN technology, within lithium
battery voltage range(3.3 V - 4.35V), output power is constant, the output power cannot drop along with
lithium battery voltage lower down. Even if the battery voltage drops, AW8736 can still provide high
quality large volume music enjoyment. There are four AW8736 operation modes, first three modes have
NCN function, the output power level is 1.2W,1W,0.8W,respectively.
Second Generation NCN technology
In audio application, output signal will be undesirable distortion caused by too large input and power
supply voltage down with battery, and clipped output signal may cause permanent damage to the speaker.
The traditional NCN function adjusts system gain automatically to generate desired output by detecting
the Crack distortion of output signal, makes the output audio signal maintain smooth, not only can
effectively avoid overloading output power to the damage of speaker, at the same time bring the constant
shock of high quality music enjoyment. The traditional NCN function is shown below in figure 6.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
13
NCNOFF NCNON
Battery
Voltage
NCNOFF NCNON
Battery
Voltage
Crack Noise
Crack Noise
Figure 6 Traditional NCN Operation Principle
AW8736 adopts Awinic unique second generation NCN technology, the output signal is free from
limitation of power rail. When battery voltage drops, NCN output signal will not distort, output amplitude
remains unchanged, keeping constant output power, as shown in figure 7. Even if the battery voltage
drops, AW8736 can still provide high quality large volume music enjoyment.
Traditional NCN function
Supply
Rail Constant
output power
Second Generation NCN funciton
Battery
Voltage
Figure 7 Second generation NCN Operation Principle
Attack time
Attack time is the time it takes for the gain to be attenuated -13.5dB once the audio signal exceeds
the NCN threshold. Fast attack times allow the NCN to react quickly and prevent transients such as
symbol crashes from being distorted. However, fast attack times can lead to volume pumping, where the
gain reduction and release becomes noticeable, as the NCN cycles quickly. Slower attack times cause
the NCN to ignore the fast transients, and instead act upon longer, louder passages. Selecting an attack
time that is too slow can lead to increased distortion in the case of the No Clip function. According to
mobile phone and portable equipment audio features, attack time of AW8736 is set to be 40ms,
effectively keeping the music rhythm, and at the same time eliminating the crack distortion, protecting the
speaker.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
14
Release time
Release time is the time it takes for the gain to return to its normal level once the audio signal returns
below the NCN threshold. A fast release time allows the NCN to react quickly to transients, preserving the
original dynamics of the audio source. However, similar to a fast attack time, a fast release time
contributes to volume pumping. A slow release time makes the music smooth and soft, it is better to
suppress the crack distortion, but longer release time will make music sounds “boring” ,lack of impact.
According to mobile phone and portable equipment audio features, release time of AW8736 is set to be
1.2s.
K-Chargepump
AW8736 adopts a new generation of charge pump technologyK -Chargepump structure, it has high
efficiency and large driving ability, working frequency is 1.1MHzbuilt in soft start circuit, current limiting
control loop and over-voltage-protection(OVP) loop, guaranteeing system stable and reliable operation.
High Efficiency
AW8736 uses K-chargepump structurebooster output voltage PVDD is 1.5 times of supply voltage
VDD, the ideal efficiency can reach 100%. K-chargepump efficiency is the ratio of output power to input
power, that is
%100*
IN
OUT
P
P
For example, in an ideal M times chargepump, the input current IIN is M times of output current
IOUTthe efficiency formula can be written as
%100*
*
%100*
** *
%100*
IN
OUT
OUTIN
OUTOUT
IN
OUT VM
V
IMV IV
P
P
M is charge pump work mode variable (1.5 times), VOUT is charge pump output voltage, VIN is
power supply voltage, IOUT is load current. For K-chargepump, the output voltage is 1.5 times of the
input voltage, the ideal charge pump efficiency is 100%, due to the charge pump internal switch loss and
IC static current loss, the actual efficiency will be less than ideal efficiency, up to 92%. Therefore,
K-chargepump booster technology can greatly improve the power efficiency.
Charge Pump Structure
Figure 8 is charge pump basic principle diagram, the charge pump used in AW8736 has seven
switches, the output voltage PVDD is 1.5 times as input voltage VDD through seven switches timing
control.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
15
+
+
CF1
2.2uF
CF2
2.2uF
VDD PVDD
C1P
C1N
C2P
C2N
S1
S2
S3
S4
S5
S6
S7
COUT
4.7uF
CIN
4.7uF
Figure 8 Charge Pump Principle Diagram
The operation of the charge pump has two phases, as shown in figure 9. In Φ 1, swtiches S1, S2 and
S3 are closed, VDD charges to the flying capacitor CF1 CF2.
+
+
CF1
2.2uF
CF2
2.2uF
VDD PVDD
C1P
C1N
C2P
C2N
S1
S2
S3
S4
S5
S6
S7
COUT
4.7uF
CIN
4.7uF
Charging Phase
Figure 9 Φ1: Flying Capacitor Charging
In Φ 2, as shown in figure 10: switches S1, S2 and S3 are disconnected, switches S4, S5, S6 and S7
are closed. Because the voltage across the capacitor can't mutation, so the voltage on flying capacitor
CF1 CF2, is added to the VDD, which make PVDD risen to a higher voltage.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
16
+
+
CF1
2.2uF
CF2
2.2uF
VDD PVDD
C1P
C1N
C2P
C2N
S1
S2
S3
S4
S5
S6
S7
COUT
4.7uF
CIN
4.7uF
Discharging Phase
Figure 10 Φ2 Flying capacitor charge transfer to the output capacitance COUT
Soft start
K-chargepump has integrated soft start function in order to limit supply power inrush current during
start-up. The supply current is limited to be 350 mA, and the soft start time is 1.2 ms.
Current Limitation Control
K-chargepump has integrated the current limitation control loop. In normal operation, when the heavy
load or a situation that make charge pump flow through very large current, the current limitation control
loop will control charge pump maximum output current capacity, that is 1.5 A;
Over Voltage Protection(OVP)Control
K-chargepump’s output voltage PVDD is a multiple of the input voltage VDD, which provide a high
voltage rail for internal power amplifier circuits, allowing the amplifiers provide greater output dynamic
range in the lithium battery voltage range, so as to realize the large volume, high quality class K audio
enjoyment. K-chargepump has integrated the over voltage protection control loop, when the input voltage
VDD is greater than 3.8V, the output voltage PVDD is no longer a multiple of VDD, but is controlled by
over voltage protection(OVP) loop and is stable in 5.8V, and the hysteresis voltage is about 50mV.
One-wire pulse control
One wire pulse control technology only needs a single GPIO port to operate the chip, complete a
variety of functions, it is very popular in the area of the GPIO port shortage and portable systems.
When the control signal line is longer, because of the signal integrity or radio frequency interference
problem, it will produce the narrow glitch signal. Awinic one wire pulse control technology integrated the
Deglitch circuit in internal control pin, which can effectively eliminate the influence of the glitch signal, as
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
17
shown in figure 11.
Deglitch
Glitch is eleminated
Control signal with glitch
SHDN
AW8736
Figure 11 Awinic Deglitch function diagram
The traditional one wire pulse control technology still receives pulse signal from control port when chip
is startup, so when the master control chip (such as mobile phone BB) sends wrong pulse during normal
operation, the system will enter into error states. AW8736 uses one wire pulse latch technology, after the
master control chip has sent pulses, the state will be latched, no longer receive the latter mis-sending
pulse signals, as shown in figure 12.
STATE 4
Traditional One Wire
Pulse Control
TLATCH
Shielding abnormal
pulse signal
STATE 3
STATE 4 STATE 3
Anti-interference One
Wire Pulse Control
Figure 12 Anti-interference One Wire Pulse Control Function Diagram
One Wire Pulse Control
AW8736 select each mode through the detection of number of the pulse signal rising edge of SHDN pin,
as shown in figure 13: When SHDN pin pull high from shutdown mode, there is only a rising edge,
AW8736 enter into mode 1,NCN output power is 1.2W; When high-low-high signal set to SHDN pin, there
are two rising edges, AW8736 enter into mode 2, NCN output power is 1W; When there are three rising
edges, AW8736 enter into mode 3,NCN output power is 0.8W; When there are four rising edges,
AW8736 enter into mode 4,NCN function is turned off; AW8736 has four operation modes, the number of
the rising edges does not allow more than four.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
18
THTL0.75us<TL,TH<10us
MODE1
MODE2
MODE3
MODE4
TOFF
Figure 13 One Wire Pulse Control
When AW8736 needs to work in different mode, PIN SHDN should be pull low longer than TOFF
first(recommended 1ms) which make the AW8736 shut down, Then send series pulse make the AW8736
enter into right mode, as shown in figure 14.
MODE2 MODE3
1ms
SHDN
Figure 14 One Wire Pulse Control Switching Sequence
RNS(RF TDD Noise Suppression)
GSM radios transmit using time-division multiple access with 217Hz intervals. The result is an RF
signal with strong amplitude modulation at 217Hz and its harmonics that is easily demodulated by audio
amplifiers.
In RF applications, improvements to both layout and component selection decrease the AW8736s
susceptibility to RF noise and prevent RF signals from being demodulated into audible noise. Minimizing
the trace lengths prevents them from functioning as antennas and coupling RF signals into the AW8736.
Additional RF immunity can also be obtained from relying on the self-resonant frequency of capacitors as
it exhibits the frequency response similar to a notch filter. Depending on the manufacturer, 10pF to 20pF
capacitors typically exhibit self resonance at RF frequencies. These capacitors, when placed at the input
pins, can effectively shunt the RF noise at the inputs of the AW8736. For these capacitors to be effective,
they must have a low-impedance, low-inductance path to the ground plane.
Some RF energy will couple onto audio traces regardless of the effort to prevent this phenomenon from
occurring, form audible TDD NoiseThe AW8736 features a unique RNS technology, which effectively
reduces RF energy, attenuate the RF TDD-noise, an acceptable audible level to the customer.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
19
VDD
GND
VOP
VON
INP
INN
Rin
Cin
AW8736
Figure 15 RF Radiation coupling schematic diagram
Filter-Free Modulation Scheme
The AW8736 features a filter-free PWM architecture that reduces the LC filter of the traditional Class-D
amplifier, increasing efficiency, reducing board area consumption and system cost.
EEE
The AW8736 features a unique Enhanced Emission Elimination (EEE) technology, that controls fast
transition on the output, greatly reduces EMI over the full bandwidth.
Pop-Click Suppression
The AW8736 features unique timing control circuit, that comprehensively suppresses pop-click noise,
eliminates audible transients on shutdown, wakeup, and power-up/down.
Protection Function
When a short-circuit occurs between VOP/VON pin and VDD/GND or VOP and VON, the over-current
circuit shutdown the device, preventing the device from being damaged. When the condition is removed,
the AW8736 reactivate itself. When the junction temperature is high, the over-temperature circuit
shutdown the device. The circuit switches back to normal operation when the temperature decreases to
safe levels.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
20
APPLICATION INFORMATION
External Input Resistor-RineGain setting
The AW8736 is a differential audio amplifier. The IC integrates two internal input resistors, which is
Rini=16.5. Take external input resistor Rine=3kΩ for an example, gain setting as follows
V/V3.61
kΩ5.613kΩ
320kΩ
RR320kΩ
A
iniine
V
Input Capacitor-Cininput high-pass cutoff frequency
The input coupling capacitor blocks the DC voltage at the amplifier input terminal. The input capacitors
and input resistors form a high-pass filter with the corner frequency:
(Hz)
CRπ21
3dB)(f inintotal
H
Setting the high-pass filter point high can block the 217Hz GSM noise coupled to inputs. Better matching
of the input capacitors improves performance of the circuit and also helps to suppress pop-click noise.
Take typical application in Figure 2 as an example:
Hz445(Hz)
nF15kΩ5.91π21
(Hz)
CRπ21
3dB)(f
inintotal
H
Supply Decoupling CapacitorCS
The AW8736 is a high-performance audio amplifier that requires adequate power supply decoupling.
Place a low equivalent-series-resistance (ESR) ceramic capacitor, typically 0.1μF. This choice of
capacitor and placement helps with higher frequency transients, spikes, or digital hash on the line.
Additionally, placing this decoupling capacitor close to the AW8736 is important, as any parasitic
resistance or inductance between the device and the capacitor causes efficiency loss. In addition to the
0.1μF ceramic capacitor, place a 10μF capacitor on the VBAT supply trace. This larger capacitor acts as
a charge reservoir, providing energy faster than the board supply, thus helping to prevent any droop in the
supply voltage.
Flying CapacitorCF
The value of the flying capacitor (CF) affects the load regulation and output resistance of the charge
pump. A CF value that is too small degrades the device’s ability to provide sufficient current drive.
Increasing the value of CF improves load regulation and reduces the charge pump output resistance to an
extent. A 2.2μF@10V capacitor is recommended.
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
21
Output CapacitorCOUT
The output capacitor value and ESR directly affect the ripple at PVDD. Increasing COUT reduces output
ripple. Likewise, decreasing the ESR of COUT reduces both ripple and output resistance. A 4.7μF@10V
capacitor is recommended.
Optional Ferrite Bead Filter
The AW8736 passed FCC and CE radiated emissions with no ferrite chip beads and capacitors. Use
ferrite chip beads and capacitors if device near the EMI sensitive circuits and/or there are long leads from
amplifier to speaker, placed as close as possible to the output pin.
Bead
1nF
1nF
VOP
VON Bead
Figure 16 Ferrite Chip Bead and capacitor
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
22
PACKAGE DESCRIPTION
SIDE VIEW
BOTTOM VIEWTOP VIEW
PIN 1# DOT
BY MARKING 2.000±0.050
2.000±0.050 FC-16
(2mmX2mm)
PIN 1#
IDENTIFICATION
0.400 Bsc
0.400 Bsc
Ø0.240±0.050
1.200
Ref.
0.203 Ref.
0.000-0.050
0.750±0.050
FC-16
Unit: mm
Ø0.23mm
0.4mm 0.4mm 0.4mm 0.4mm 0.4mm
0.4mm 0.4mm 0.4mm 0.4mm 0.4mm
PAD Dimention
A1
A2
A3
A4
B1
B2
B3
B4
C1
C2
C3
C4
D1
D2
D3
D4
AW8736 Data Sheet
May 2013 V1.5
High efficiencyUltralow distortionConstant large volumeSixth
generation Class K Audio Amplifier
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
23
VERSION INFORMATION
Version
Description
Owner
Date
V0.9
AW8736FCR datasheet preliminary
Zhanghaijun
2012-10-31
V1.0
AW8736FCR datasheet released
Zhanghaijun
2012-11-30
V1.1
Add SNR characteristics
Zhanghaijun
2013-01-05
V1.2
Add 12V/V gain mode description and add PA output power under 4ohm
load condition
Zhanghaijun
2013-02-22
V1.3
Add footmark on Bonding pad figure
Zhanghaijun
2013-03-29
V1.4
1 Change the output capacitor COUT maximum voltage to 10V
2 Add charge pump efficiency test condition
3 Add charge pump operation frequency
4 Change the cell phone operation voltage range as 3.3V~4.35V
5 Change the K-chargepump part description(Page14)
Zhanghaijun
2013-04-19
V1.5
Highlight AW8736 pin number in Page 1
Zhanghaijun
2013-05-21
AWINIC Technology cannot assume responsibility for use of any circuitry other than circuitry entirely
embodied in an AWINIC Technologies product. No intellectual property or circuit patent licenses are
implied. AWINIC Technology reserves the right to change the circuitry and specifications without notice at
any time.