AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
FEATURES
DESCRIPTION
New generation charge pump technology ：
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 technology：K -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.
K-Chargepump，efficiency reaches as high as
92%
Power amplifier overall efficiency 75%，greatly
prolong mobile phone usage time
Ultra-low distortion：0.02%
Within Lithium battery voltage range, output
power is maintained constant
Output Power level：0.8W、1W、1.2W
Second generation Non-crack-noise (NCN)
technology
Super TDD-Noise suppression
Ultra-low EMI
One wire pulse control
High PSRR：-65dB（217Hz）
Small 2mm×2mm FC-16package
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.
APPLICATIONS
Smart phone
DEVICE PINOUT
AW8736FCR TOP VIEW
AW8736FCR MARKING
D
C2P
C1P
PVDD
VON
D
C
C1N
GND
GND
GND
C
8736
B
C2N
C2N
VDD
VOP
B
XXXX
A
INP
INN
VDD
SHDN
A
1
2
3
4
1
2
3
8736 – AW8736FCR
XXXX–Production tracking code
Please notice the pin number
Figure 1 AW8736FCR pin diagram top view and device marking
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
1
4
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
PIN DESCRIPTION
Number
Symbol
Description
A1
A2
A3，B3
A4
B1
B2
B4
C1
C2
C3
C4
D1
D2
D3
D4
INP
INN
VDD
SHDN
C2N
Positive audio input terminal
Negative audio input terminal
Power supply
Chip power down pin，active low；one wire pulse control；
Negative side of the external charge pump flying capacitor C2
VOP
C1N
Positive audio output terminal
Negative side of the external charge pump flying capacitor C1
GND
Ground
C2P
C1P
PVDD
VON
Positive side of the external charge pump flying capacitor C2
Positive side of the external charge pump flying capacitor C1
Boost charge pump output voltage
Negative audio output terminal
APPLICATION DIAGRAM
VBAT
CS1
4.7uF
A3,B3
VDD
A4
Pulse Input
1
Single-Ended
Input
2
3
CF2
2.2uF
CF1
2.2uF
CS2
0.1uF
D2
C1
C1P C1N
D1
C2P
SHDN
B1,B2
C2N
PVDD
D3
COUT
4.7uF
4
15nF
3KΩ
Cin
Rin
A2
INN
AW8736
C1
220pF
Cin
Rin
15nF
3KΩ
A1
VOP
B4
B1
C2
1nF
INP
VON
D4
B2
C3
1nF
GND
C2,C3,C4
Figure 2 AW8736 single-ended input application diagram (Note 1)
Note1：when single-ended input，input audio signal can arbitrarily connect to one of INN，INP input terminal，
the other terminal connects to ground through input capacitor and resistance.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
2
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
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.
VBAT
CS1
4.7uF
A3,B3
D2
C1
C1P C1N
VDD
A4
Pulse Input
1
Differential
Input
3
2
3KΩ
Cin
Rin
SHDN
A2
B1,B2
C2N
PVDD
D3
COUT
4.7uF
INN
AW8736
C1
220pF
15nF
D1
C2P
4
15nF
Cin
CF2
2.2uF
CF1
2.2uF
CS2
0.1uF
Rin
A1
VOP
B4
B1
C2
1nF
INP
3KΩ
VON
D4
B2
C3
1nF
GND
C2,C3,C4
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
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
3
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
ABSOLUTE MAXIMUM RATING(Note2)
Parameter
Range
Supply Voltage VDD
-0.3V to 6V
INP，INN 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 Temperature（Soldering 10 Seconds）
260℃
ESD Rating（Note 3）
HBM（human body model）
±6KV
Latch-up
Test Condition：JEDEC STANDARD NO.78B DECEMBER 2008
+IT：450mA
-IT：-450mA
Note 2：Stresses 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 3：The 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 Cin，outer input resist is Rin，inner input resist is 16.5KΩ，
gain Av is 320K/(Rin+16.5K). Recommended typical application is：
1、 Cin=15nF，Rin=3KΩ，Av=16.3V/V；
2、 Cin=15nF，Rin=10KΩ，Av=12V/V；
Mode
Enable
Signal
NCN Power（W）
RL=8Ω
RL=4Ω
NCN
function
Gain（V/V）
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%
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
4
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
ELECTRICAL CHARACTERISTICS
Test condition：TA=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
30
mV
1
μA
|VOS|
Output offset voltage
Vin=0V，VDD=3.0V to 5.0V
-30
0
ISD
Shutdown current
VDD=3.6V， SHDN =0V
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
1.5*
VDD =3.0V to 3.8V
PVDD
V
VDD
Output voltage
VDD >3.8V
5.8
V
OVP hysteresis
VDD >3.8V
50
mV
FCP
Charge Pump frequency
VDD=3.0V to 5.0V
ηCP
Charge pump efficiency
VDD=4.2V, Iload=200mA
TST
Soft-start time
No load，COUT=4.7uF
Vhys
IL
0.8
1.06
1.33
92
1
Current limit when PVDD short
to ground
1.2
MHz
%
1.4
ms
350
mA
Class K power amplifier（mode1-mode4）
Iq
Quiescent current
VDD=3.6V，Vin=0，no load
9.5
mA
η
Efficiency
VDD=4.2V，Po=1.2W，RL=8Ω
75
%
Modulation frequency
VDD=3.0V to 5.0V
Av
gain
Outside input resistance=3kΩ
Rini
Inner input resistance
Fosc
600
800
1000
kHz
16.3
V/V
16.5
kΩ
VDD=4.2V，RL=8Ω
1.2
W
VDD=4.2V，RL=4Ω
2.25
W
VDD=4.2V，RL=8Ω
1
W
VDD=4.2V，RL=4Ω
2
W
VDD=4.2V，RL=8Ω
0.8
W
VDD=4.2V，RL=4Ω
1.6
W
-65
dB
Mode1 NCN output power
Pncn
Mode2 NCN output power
Mode3 NCN output power
PSRR
Power supply rejection ratio
VDD=4.2V，Vp-p_sin=200mV
217Hz
-53
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
5
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
1kHz
SNR
Vn
THD+N
PO
Signal-to-noise ratio
Output noise voltage
Total harmonic
distortion+noise
-53
-65
dB
VDD=4.2V，Po=0.8W，RL=8Ω
84.5
dB
VDD=4.2V，Po=1.65W，RL=8Ω
87.5
dB
VDD=4.2V，f=20Hz to 20kHz，
A-weighting
input ac grounded
155
uVrms
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
%
THD+N=10%，f=1kHz，RL=8Ω，VDD=4.2V
2.0
W
THD+N=1%，f=1kHz，RL=8Ω，VDD=4.2V
1.65
W
THD+N=10%，f=1kHz，RL=8Ω，VDD=3.6V
1.5
W
THD+N=1%，f=1kHz，RL=8Ω，VDD=3.6V
1.23
W
THD+N=10%，f=1kHz，RL=4Ω，VDD=4.2V
2.58
W
THD+N=1%，f=1kHz，RL=4Ω，VDD=4.2V
2.15
W
THD+N=10%，f=1kHz，RL=4Ω，VDD=3.6V
1.85
W
THD+N=1%，f=1kHz，RL=4Ω，VDD=3.6V
1.55
W
Mode4 output power
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
NCN（note 4）
TAT
Attack time(-13.5dB)
40
ms
TRL
Release time（13.5dB）
1.2
s
-13.5
dB
AMAX
Maximum attenuation
Note 4：Attack time points to 13.5dB gain attenuation time；Release 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.
10nF
500Ω
VOP
INP
Cin
Rin
30kHz
Low-Pass Fliter
K6
VON
INN
Cin
500Ω
Rin
10nF
Figure 4
AW8736 test setup
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
6
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
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
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
7
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
TYPICAL CHARACTERISTICS
AMPLIFIER EFFICIENCY vs OUTPUT POWER
100
90
90
80
VDD=3.6V
VDD=3.3V
70
80
VDD=4.2V
Efficiency( % )
Efficiency( % )
K-CHARGEPUMP EFFICIENCY vs OUTPUT POWER
100
60
50
40
30
70
60
50
40
30
20
20
RL=8Ω+33μH
10
VDD=4.2V
CF1,CF2=2.2μF
COUT=4.7μF
10
0
0
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
1.8
2
0
0.2
0.4
0.6
0.8
1
1.2
1.4
Output Power ( W )
Output Power ( W )
NCN OUTPUT POWER vs SUPPLY VOLTAGE
GAIN vs FREQUENCY
1.6
1.8
2
1.4
24
AW8736 output power remain constant
MODE1
1.2
22
18
Gain( V/V )
NCN Output Power( W )
20
MODE2
1.0
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
MODE3
0.8
0.6
16
14
12
10
8
0.4
6
4
0.2
2
RL=8Ω+33μH
0
3.3
3.5
3.7
3.9
4.3
4.1
50
100
1K
Supply Voltage ( V )
THD+N vs FREQUENCY
20K
THD+N vs FREQUENCY
10
10
MODE2
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
MODE1
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
1
THD+N (%)
THD+N (%)
10K
Frequency ( Hz )
1
0.1
0.1
0.01
0.01
50
100
1K
10K
50
20K
100
1K
Frequency ( Hz )
Frequency ( Hz )
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
8
10K
20K
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
THD+N vs OUTPUT POWER
THD+N vs FREQUENCY
10
10
Mode4
f=1kHz
Cin=1μF
RL=8Ω+33μH
1
1
THD+N (%)
THD+N (%)
Mode3
VDD=4.2V
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
VDD=3.6V
VDD=4.2V
0.1
0.1
0.01
0.01
50
100
10K
1K
20K
0.5
0.2
Frequency ( Hz )
OUTPUT POWER vs VIN
2
Mode2
VDD=4.2V
f=1kHz
RL=8Ω+33μH
Mode1
VDD=4.2V
f=1kHz
RL=8Ω+33μH
1
Output Power (W)
Output Power (W)
2
OUTPUT POWER vs VIN
2
1
1
Output Power( W )
NCN
0.5
0.1
0.5
NCN
0.1
0.1
0.5
1
2
0.1
1
0.5
VIN ( Vp )
2
VIN ( Vp )
QUIESCENT CURRENT vs SUPPLY VOLTAGE
OUTPUT POWER vs VIN
14
2
Mode3
VDD=4.2V
f=1kHz
RL=8Ω+33μH
12
Quiescent Current(mA )
Output Power (W)
1
0.5
NCN
10
8
6
4
2
RL=8Ω+33μH
0.1
0.1
0
0.5
1
2
3.3
3.5
3.7
3.9
Supply Voltage ( V )
VIN ( Vp )
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
9
4.1
4.3
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
PSRR vs FREQUENCY
PSRR vs FREQUENCY
0
0
Mode1
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
-10
-20
-20
-30
PSRR (dB)
-30
PSRR (dB)
Mode2
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
-10
-40
-50
VDD=3.6V
VDD=4.2V
-40
-50
-60
-60
-70
-70
-80
-80
-90
VDD=3.6V
VDD=4.2V
-90
20
100
10K 20K
1K
20
100
Frequency ( Hz )
PSRR vs FREQUENCY
PSRR vs FREQUENCY
0
0
Mode3
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
-10
-20
Mode4
Rine=3kΩ
Cin=1μF
RL=8Ω+33μH
-10
-20
-30
PSRR (dB)
-30
PSRR (dB)
10K 20K
1K
Frequency ( Hz )
-40
-50
VDD=4.2V
VDD=3.6V
-40
-50
-60
-60
-70
-70
-80
-80
-90
VDD=4.2V
VDD=3.6V
-90
20
100
10K 20K
1K
20
100
Frequency ( Hz )
10K 20K
1K
Frequency ( Hz )
START-UP SEQUENCE
SHUTDOWN SEQUENCE
SHDN
SHDN
VOP&VON
6ms/div
VOP&VON
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
10
50μs/div
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
NCN ATTACK TIME
NCN RELEASE TIME
Vin
Vin
VOP-VON
VOP-VON
200ms/div
10ms/div
FUNCTIONAL DIAGRAM
C1P
VDD
C1N
C2P
C2N
OVP
SHDN
K-Chargepump
SHDN&BIAS
PVDD
Current
Limit
SEGMENTED
OTP
OSC
VOP
INP
INPUT
BUFFER
Class-K
Modulator
INN
Ultra Low
EMI
output
stage
OCP
NCN
Noise
Cancellor
AW8736
GND
Figure 5
AW8736 functional diagram
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
11
VON
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
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 technology：K -Chargepump structure, built in current limiting control loop and
over-voltage-protection(OVP) loop，efficiency 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.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
12
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
Crack Noise
Battery
Voltage
NCNOFF
NCNON
Crack Noise
Battery
Voltage
NCNOFF
Figure 6
NCNON
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.
Supply
Rail
Battery
Voltage
Traditional NCN function
Figure 7
Constant
output power
Second Generation NCN funciton
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.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
13
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
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 technology：K -Chargepump structure, it has high
efficiency and large driving ability, working frequency is 1.1MHz，built 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 structure，booster 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
POUT
*100 %
PIN
For example, in an ideal M times chargepump, the input current IIN is M times of output current
IOUT，the efficiency formula can be written as：
POUT
V *I
V
*100 % OUT OUT *100 % OUT *100 %
PIN
VIN * M * I OUT
M *VIN
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.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
14
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
S1
C1P
+
VDD
CIN
4.7uF
S6
CF1
2.2uF
S4
PVDD
COUT
4.7uF
C1N
S2
+
S7
C2P
CF2
2.2uF
S5
S3
C2N
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.
S1
C1P
+
VDD
CIN
4.7uF
S6
CF1
2.2uF
S4
PVDD
COUT
4.7uF
C1N
S2
+
S7
C2P
CF2
2.2uF
S3
S5
C2N
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.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
15
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
S1
C1P
+
VDD
CIN
4.7uF
S6
CF1
2.2uF
S4
PVDD
COUT
4.7uF
C1N
S2
+
S7
C2P
CF2
2.2uF
S3
S5
C2N
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
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
16
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
shown in figure 11.
AW8736
SHDN
Deglitch
Control signal with glitch
Glitch is eleminated
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.
TLATCH
STATE 4
STATE 3
Traditional One Wire
Pulse Control
Shielding abnormal
pulse signal
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.
COPYRIGHT ©2012 SHANGHAI AWINIC TECHNOLOGY CO., LTD.
17
AW8736 Data Sheet
May 2013 V1.5
High efficiency、Ultralow distortion、Constant large volume、Sixth
generation Class K Audio Amplifier
MODE1
MODE2
MODE3
MODE4
TH TL
0.75us
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