ft2011A [FANGTEK]
3W Low EMI Class-D Audio Power Amplifier with Auto-Recovering Short-Circuit Protection;型号: | ft2011A |
厂家: | Fangtek Ltd. |
描述: | 3W Low EMI Class-D Audio Power Amplifier with Auto-Recovering Short-Circuit Protection |
文件: | 总21页 (文件大小:841K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
ft2011
3W Low EMI Class-D Audio Power Amplifier
with Auto-Recovering Short-Circuit Protection
GENERAL DESCRIPTION
FEATURES
Filterless Class-D operation
The ft2011 is a high efficiency, low EMI, filterless,
Class-D audio amplifier with auto-recovering
short-circuit protection. It operates from 3V to
5.5V supply. When powered with 5V supply
voltage, the ft2011 is capable of delivering 3W
into a 4Ω load or 1.8W into an 8Ω load, with 10%
THD+N.
High efficiency up to 90%
Maximum output power at 5V supply
3.0W (4Ω load, 10% THD+N)
1.8W (8Ω load, 10% THD+N)
Maximum output power at 3.6V supply
1.5W (4Ω load, 10% THD+N)
As a Class-D audio amplifier, the ft2011 features
90% efficiency and 75dB PSRR at 217Hz which
make the device ideal for battery-powered
high-quality audio applications.
0.9W (8Ω load, 10% THD+N)
Low THD+N: 0.05%
(VDD=3.6V, f=1kHz, RL=8Ω, PO=0.5W)
Low quiescent current: 2mA @ VDD=3.6V
Low shutdown current < 0.1µA
High PSRR: 75dB @ 217Hz
One of the key benefits of the ft2011 over typical
Class-D audio power amplifiers is it generates
much less EMI emissions, thus greatly simplifying
the system design for portable applications. Also
included is the over-current and short-circuit
protection with auto-recovery, which ensures the
device be operated safely and reliably without the
need for system interaction.
No bypass capacitor required for the
common-mode bias
Under-voltage lockout
Auto-recovering over-current and
short-circuit protection
Thermal overload protection
Low EMI design
APPLICATIONS
Mobile Phones
Available in COL1.5x1.5-9L, SOP-8L,
MSOP-8L, and DFN2x2-8L packages
Portable Navigation Devices
Multimedia Internet Devices
Portable Speakers
APPLICATION CIRCUIT
To Battery
To Battery
Cs
1uF
Cs
1uF
VDD/PVDD
ft2011
VDD/PVDD
ft2011
Ci
Ci
Ri
Ri
INN
Differential Input
INP
INN
INP
INN
INN
INP
VON
VON
Single-ended Input
Ri
Ri
Ci
VOP
VOP
Ci
SHDN
GND/PGND
SHDN
GND/PGND
ON
ON
OFF
OFF
Figure 1: Typical Audio Amplifier Application Circuit
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ft2011
PIN CONFIGURATION AND DESCRIPTION
V O N
G N D
P G N D
1
2
3
4
8
7
6
5
S H D N 1
8
7
6
5
3
2
1
V O P
S H D N
NC
S H D N 1
8
V O N
G N D
V O N
G N D
V O N
NC
2
G N D
V D D
NC
2
3
4
7
6
5
P V D D S H D N
I N P
I N N
I N P
3
V D D
V O P
V D D
V O P
I N P
I N N
I N N
4
I N P
A
V D D
B
I N N
C
V O P
ft2011A
(TOP VIEW)
ft2011P
(TOP VIEW)
ft2011M
(TOP VIEW)
ft2011N
(TOP VIEW)
PIN NUMBER
PIN NAME
DESCRIPTION
ft2011A
ft2011P
ft2011M
ft2011N
SHDN
NC
C2
1
1
1
2
3
4
5
Active low shutdown control.
No internal connection.
2
3
4
5
2
3
4
5
INP
A1
C1
C3
B1
Positive audio input terminal.
Negative audio input terminal.
INN
VOP
VDD
Positive BTL audio output terminal.
Power supply.
Power supply for the output stage. For ft2011P/M/N,
it is internally shorted to VDD. For 2011A, it must be
externally shorted to VDD on the system board.
6
6
6
PVDD
GND
B2
A2
B3
A3
Ground.
Power ground for the output stage. For ft2011P/M/N,
it is internally shorted to GND. For 2011A, it must be
externally shorted to GND on the system board.
7
8
7
8
7
8
PGND
VON
Negative BTL audio output terminal.
ORDERING INFORMATION
PART NUMBER
ft2011A
TEMPERATURE RANGE
-40°C to +85°C
PACKAGE
COL1.5x1.5-9L
SOP-8L
ft2011P
-40°C to +85°C
ft2011M
-40°C to +85°C
MSOP-8L
ft2011N
-40°C to +85°C
DFN2x2-8L
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ft2011
ABSOLUTE MAXIMUM RATINGS
PARAMETER
UNIT
Supply Voltage
-0.3V to 6.0V
-0.3V to VDD+0.3V
Internally Limited
4000V
All Other Pins
Power Dissipation
ESD Rating (HBM)
Junction Temperature
Storage Temperature
150°C
-45°C to 150°C
Soldering Information
Vapor Phase (60 sec.)
Infrared (15 sec.)
215°C
220°C
Note: Stresses beyond those listed under absolute maximun ratings 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 under recommended operating conditions is not
implied.Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
PACKAGE DISSIPATION RATINGS
PACKAGE
Θ
JA
UNIT
COL1.5x1.5-9L
SOP-8L
190
140
180
100
°C/W
°C/W
°C/W
°C/W
MSOP-8L
DFN2x2-8L
RECOMMENDED OPERATING CONDITIONS
PARAMETER
CONDITIONS
MIN
TYP
MAX
5.5
UNIT
Supply Voltage,VDD
3
V
°C
Ω
Operating Free-Air Temperature, TA
Minimum Load Resistance, RLOAD
-40
3.2
85
IMPORTANT APPLICATION NOTES
1. The ft2011, as a Class-D power audio amplifier, requires adequate power supply decoupling to ensure
its optimum performance such as output power, efficiency, and THD+N. Place decoupling capacitors as
close to the VDD pin as possible. For applications where the load resistance is less than 6Ω, it is
strongly recommended to use a 4.7µF to 10µF capacitor for power supply decoupling.
2. It is recommended to employ a ground plane for ft2011 on the system board.
3. Use a simple ferrite bead filter for further EMI suppression. Choose a ferrite bead with a rated current
no less than 2A or greater for applications with a load resistance less than 6Ω. Also, place the
respective ferrite beard filters as close to the output pins, VOP and VON, as possible.
4. For applications where the power supply is rated more than 4.6V or the load resistance less than 6Ω, it
is strongly recommended to add a simple snubber circuit (as shown in Figure 23) between the two
output pins, VOP and VON, to prevent the device from accelerated deterioration or abrupt destruction
due to excessive inductive flybacks that are induced on fast output switching or by an over-current or
short-circuit condition.
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ft2011
FUNCTIONAL BLOCK DIAGRAM
VDD
PVDD
VON
150KΩ
Output
Driver
VDD
INN
PWM
Modulator
INP
VOP
Output
Driver
PGND
150KΩ
Startup
Protection
Logic
SHDN
Shutdown
Control
OCP
300KΩ
BIAS
OSC
Note:
Total Gain=2x150KΩ/Ri
GND
Figure 2: Simplified Function Block Diagram of ft2011
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ft2011
ELECTRICAL CHARACTERISTICS
TA=25°C, VDD = 3.6V, RL=8Ω, Gain = 2V/V, RI=150kΩ, CI=0.1µF, f=1kHz, unless otherwise noted.
SYMBOL PARAMETER
CONDITIONS
MIN
TYP
MAX
UNIT
VDD
Supply Voltage
3.0
5.5
V
V
V
VUVLU
VUVLD
Power Up Threshold Voltage
Power Down Threshold Voltage
VDD from Low to High
VDD from High to Low
2.2
2.0
VDD=5V, No Load
Inputs AC-Grounded
1.5
1.4
2.2
4.0
3.6
mA
mA
IDD
Quiescent Current
VDD=3.6V, No Load
Inputs AC-Grounded
2.0
0.1
SHDN Low
ISD
Shutdown Current
SHDN Input High
SHDN Input Low
µA
V
VSDIH
VSDIL
1.3
0.4
V
THD+N=10%
THD+N=1%
THD+N=10%
THD+N=1%
THD+N=10%
THD+N=1%
THD+N=10%
THD+N=1%
1.8
1.4
Maximum Output Power
VDD=5V, Load=8Ω
W
W
W
PO
0.9
Maximum Output Power
VDD=3.6V, Load=8Ω
0.7
3.0
Maximum Output Power
VDD=5V, Load=4Ω
2.4
PO
AV
1.5
Maximum Output Power
VDD=3.6V, Load=4Ω
W
1.2
Gain
300kΩ / Ri
V/V
Output Resistance in Shutdown
SHDN Input Resistance
SHDN Low
RO
2
kΩ
kΩ
V
RSHDN
VREF
300
VREF Voltage
VDD/2
0.05
0.07
0.06
0.08
VDD=3.6V, PO=0.5W
VDD=5V, PO=1W
VDD=3.6V, PO=1W
VDD=5V, PO=2W
Total Harmonic Distortion + Noise
Load=8Ω
%
THD+N
Total Harmonic Distortion + Noise
Load=4Ω
%
Bandwidth = 20Hz ~ 20kHz
Inputs AC-Grounded
VN
Output Voltage Noise
85
µVRMS
VOS
η
Output Offset Voltage
Inputs AC-Grounded
VDD=5V, PO=1W
f=217Hz
+5
90
mV
%
Efficiency
PSRR
CMRR
TSTUP
fPWM
Power Supply Rejection Ratio
Common Mode Rejection Ratio
Startup Time
75
dB
dB
ms
kHz
kHz
A
70
35
PWM Carrier Frequency
PWM Frequency Jittering Range
Over-Current Threshold
Over-Temperature Threshold
Over-Temperature Hysteresis
800
±24
2.0
160
30
fJITTER
ILIMIT
VDD=5V
TOTP
THYS
C
C
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ft2011
TEST SETUP FOR PERFORMANCE TESTING
Ci
Ci
Ri
Ri
INP
INN
+
VOP
VON
+
Measurement
Output
33KHz
Low pass
Filter
Measurement
Input
ft2011
_
_
LOAD
VDD
GND
1uF
+
VDD
_
Figure 3: Test Block Diagram
Notes: 1) A 33µH inductor is placed in series with the load resistor to emulate a small speaker for efficiency measurements;
2) The 33kHz lowpass filter is added onto the audio outputs, VOP and VON even if the analyzer has an internal lowpass
filter. An RC lowpass filter (100Ω, 47nF) is used on each output for the data sheet graphs.
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ft2011
TYPICAL PERFORMANCE CHARACTERISTICS
TA=25°C, VDD = 3.6V, Gain = 2V/V, RI=150kΩ, CI=0.1µF, f=1kHz, ft2011M, unless otherwise noted.
List of Performance Characteristics
DESCRIPTION
CONDITIONS
FIGURE #
R
L
=4Ω+33µH, THD+N=1% & 10%
=8Ω+33µH, THD+N=1% & 10%
4
Output Power vs. Supply Voltage
RL
5
Output Power vs. Input Voltage
VDD=5.0V, R
L
=4Ω+33µH & 8Ω+33µH
6
Quiescent Current vs. Supply Voltage
Input AC-Grounded, No Load
7
VDD=5.0V, R
VDD=3.6V, R
VDD=5.0V, R
VDD=3.6V, R
VDD=5.0V, R
VDD=3.6V, R
VDD=5.0V, R
VDD=3.6V, R
L
L
L
L
L
L
L
L
=8Ω+33µH
=8Ω+33µH
=4Ω+33µH,
=4Ω+33µH
=8Ω+33µH
=8Ω+33µH
=4Ω+33µH
=4Ω+33µH
8
9
Efficiency vs. Output Power
10
11
12
13
14
15
16
17
18
19
20
21
THD+N vs. Output Power
THD+N vs. Frequency
VDD=5.0V, Po=1W, R
L
=4Ω+33µH & 8Ω+33µH
=4Ω+33µH & 8Ω+33µH
VDD=3.6V, Po=0.5W, R
L
PSRR vs. Input Frequency
VDD=4.0V, R
L
L
=8Ω+33µH, Input AC-Grounded
=8Ω+33µH, Vin=0.1VRMS
Auto-Recovering SCP Waveforms
Broadband Output Spectrum
Audio-Band Output Spectrum
VDD=4.0V, R
VDD=4.0V, No Load, Vin=0.25VRMS
VDD=4.0V, No Load, Vin=0.25VRMS
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ft2011
TYPICAL PERFORMANCE CHARACTERISTICS (Cont’d)
Output Power vs Supply Voltage
Output Power vs Supply Voltage
4
3.5
3
2.5
2
RL=4Ω+33uH, THD+N=1%
RL=4Ω+33uH, THD+N=10%
RL=8Ω+33uH, THD+N=1%
RL=8Ω+33uH, THD+N=10%
2.5
2
1.5
1
1.5
1
0.5
0.5
0
0
2.5
3
3.5
4
4.5
5
5.5
2.5
3
3.5
4
4.5
5
5.5
Supply Voltage (V)
Supply Voltage (V)
Figure 4: Output Power vs. Supply Voltage
Figure 5: Output Power vs. Supply Voltage
Quiescent Current vs Supply Voltage
Output Power vs Input Voltage
5
10000
4.5
4
3.5
3
1000
No Load
2.5
2
100
10
VDD=5V, RL=8Ω+33uH
VDD=5V, RL=4Ω+33uH
1.5
1
0.5
0
100
1000
Input Voltage (mVrms)
10000
2.5
3.0
3.5
4.0
Supply Voltag (V)
4.5
5.0
5.5
Figure 6: Output Power vs. Input Voltage
Figure 7: Quiescent Current vs. Supply Voltage
Efficiency vs Output Power
Efficiency vs Output Power
100%
90%
80%
70%
60%
50%
40%
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
30%
VDD=3.6V, RL=8Ω+33uH
VDD=5V, RL=8Ω+33uH
20%
10%
0%
0
100
200
300
400
500
600
700
800
900
0
200
400
600
800
1000 1200 1400 1600 1800
Output Power(mW)
Output Power(mW)
Figure 8: Efficiency vs. Output Power
Figure 9: Efficiency vs. Output Power
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ft2011
TYPICAL PERFORMANCE CHARACTERISTICS (Cont’d)
Efficiency vs Output Power
Efficiency vs Output Power
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
VDD=3.6V,RL=4Ω+33uH
VDD=3.6V, RL=8Ω+33uH
0
200
400
600
800
1000
1200
1400
1600
0
100
200
300
400
500
600
700
800
900
Output Power(mW)
Output Power(mW)
Figure 10: Efficiency vs. Output Power
Figure 11: Efficiency vs. Output Power
THD+N VS Output Power
THD+N VS Output Power
100
100
10
10
1
VDD=3.6V, RL=8Ω+33uH
VDD=5V, RL=8Ω+33uH
1
0.1
0.1
0.01
0.01
10
100
1000
Output Power (mW)
10000
10
100
1000
10000
Output Power (mW)
Figure 12: THD+N vs. Output Power
Figure 13: THD+N vs. Output Power
THD+N VS Output Power
THD+N VS Output Power
100
10
100
10
VDD=3.6V,RL=4Ω+33uH
VDD=5.0V,RL=4Ω+33uH
1
1
0.1
0.01
0.1
0.01
10
100
1000
Output Power (mW)
10000
10
100
1000
Output Power (mW)
10000
Figure 14: THD+N vs. Output Power
Figure 15: THD+N vs. Output Power
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ft2011
TYPICAL PERFORMANCE CHARACTERISTICS (Cont’d)
THD+N vs Frequency
THD+N vs Frequency
10.00
1.00
0.10
0.01
10.00
1.00
0.10
0.01
VDD=5V,1W RL=4Ω+33uH
VDD=5V,1W RL=8Ω+33uH
VDD=3.6V,0.5W RL=4Ω+33uH
VDD=3.6V,0.5W RL=8Ω+33uH
10
100
1000
10000
100000
10
100
1000
10000
100000
Frequency (Hz)
Frequency (Hz)
Figure 16: THD+N vs. Frequency
Figure 17: THD+N vs. Frequency
PSRR vs. Frequency
0
-10
-20
-30
-40
-50
-60
-70
-80
VDD =4±0.2V, RL=8Ω+33uH, Input AC-Grounded
10
100
1000
10000
100000
Frequency(Hz)
Figure 18: PSRR vs. Frequency
Figure 19: Auto Recovering SCP Waveforms
Figure 20: Broadband Output Spectrum
Figure 21: Audio-Band Output Spectrum
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ft2011
APPLICATION INFORMATION
The ft2011 is a high efficiency, low EMI, filterless, Class-D audio power amplifier with auto-recovering
short-circuit protection. The ft2011 operates from 3V to 5.5V supply. When powered with 5V supply voltage,
the ft2011 is capable of delivering up to 3W into a 4Ω load or 1.8W into an 8Ω load, with 10% THD+N.
As a Class-D power audio amplifier, the ft2011 features 90% high efficiency and 75dB PSRR at 217Hz
which make the device ideal for battery-supplied, high-quality audio applications. One of the key benefits of
the ft2011 over typical Class-D audio power amplifiers is it generates much less EMI emissions, thus
greatly simplifying the system design for portable applications. Also included are the circuitry to minimize
turn-on and turn-off transients (also known as pops and clicks) and auto-recovering over-current protection
(OCP) and short-circuit protection (SCP).
Furthermore, the ft2011 includes under-voltage lockout to ensure proper operation when the device is first
powered up; and thermal-overload protection to safeguard the die temperature during operation.
Fully Differential Amplifier
The ft2011 is configured in a fully differential topology. The fully differential topology ensures that the
amplifier outputs a differential voltage on the output that is equal to the differential input times the gain. The
common-mode feedback ensures that the common-mode voltage at the output is biased around VDD/2
regardless of the common-mode voltage at the input. Although the fully differential topology of the ft2011
can still be used with a single-ended input, it is highly recommended that the ft2011 be used with differential
inputs in a noisy environment, like a wireless handset, to ensure maximum noise rejection.
Filterless Design
Traditional Class-D amplifiers require an output filter. The filter adds cost and the size of the system board.
Furthermore, it degrades the performance of power efficiency and THD+N. The ft2011’s filterless
modulation scheme does not require an output filter. Because the switching frequency of the ft2011 is well
beyond the bandwidth of most speakers, voice coil movement due to the switching frequency is very small.
Use a speaker with a series inductance larger than 10µH. An 8Ω speaker typically exhibits a series
inductance in the range from 20µH to 100µH.
However, LC filter is required when the trace between the ft2011 and the speaker exceeds 100mm. Long
trace acts like tiny antenna and generates EMI emissions which may result in FCC and CE certification
failures.
Low EMI Design
Traditional Class-D amplifiers require the use of external LC filters or shielding to minimize EMI emissions.
The ft2011 employs a proprietary design of the amplifier output stage in conjunction with frequency jittering
technique to minimize EMI emissions while maintaining high efficiency.
How to Reduce EMI
The ft2011 does not require an LC output filter for short connections from the amplifier to the speaker.
However, additional EMI suppressions can be made by use of a ferrite bead in conjunction with a capacitor,
as shown in Figure 22. Choose a ferrite bead with low DC resistance (DCR) and high impedance (100Ω ~
330Ω) at high frequencies (>100MHz). The current flowing through the ferrite bead must be also taken into
consideration. The effectiveness of ferrites can be greatly aggravated at much lower than the rated current
values. Choose a ferrite bead with a rated current value no less than 2A. The capacitor value varies based
on the ferrite bead chosen and the actual speaker lead length. Choose a capacitor less than 1nF based on
EMI performance.
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ft2011
Ferrite
Chip Bead
VOP
VON
FB1 220Ω/2A
C1
1nF
Ferrite
Chip Bead
FB2 220Ω/2A
C2
1nF
Figure 22: Ferrite Bead Filter to Reduce EMI
RC Snubber Circuit
For applications where the power supply is rated more than 4.6V or the load resistance less than 6Ω, it may
become necessary to add an RC snubber circuit between the two output pins, VOP and VON, for
robustness and reliability. Figure 23 shows a simple RC snubber circuit, which can be used to prevent the
device from accelerated deterioration or abrupt destruction due to excessive inductive flybacks that are
induced on fast output switching or by an over-current or short-circuit condition.
VOP
R1
1Ω~1.5Ω
SPEAKER
C1
680pF~1nF
VON
Figure 23: RC Snubber Circuit
Shutdown Operation
In order to reduce power consumption while the device is not in use, the ft2011 includes shutdown circuitry
to de-bias all the internal circuitry when the SHDN pin is pulled low. During shutdown, the supply current of
the ft2011 is reduced less than 0.1µA, typically.
Under Voltage Lockout (UVLO)
The ft2011 incorporates circuitry designed to detect a low supply voltage. When the supply voltage drops
below 2.0V (typical), the ft2011 goes into shutdown mode. The device will emerge out of the shutdown
mode and resume its normal operation only when the supply voltage is restored to above 2.2V (typical) and
the SHDN pin pulled high.
Auto-Recovering Over-Current Protection (OCP) & Short-Circuit Protection (SCP)
Once an over-current or a short-circuit condition at the differential outputs, either to the power supply or to
ground or to each other, is detected, the ft2011 goes into shutdown mode. During shutdown, the ft2011
activates auto-recovering process whose aim is to return the device to normal operation once the fault
condition is removed. This process repeatedly examines if the fault condition persists, and returns the
device to normal operation immediately after the fault condition is removed. This feature helps protect the
device from large currents and maintain long-term reliability while removing the need for external system
interaction to resume normal operation.
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ft2011
Over-Temperature Shutdown (OTSD)
The thermal-overload protection on the ft2011 prevents the device from being damaged when the die
temperature exceeds 160°C. Once the die temperature exceeds the prescribed value, the device will be
forced into shutdown mode and the outputs are disabled. Note that this is not a latched fault. Instead, the
thermal fault will be cleared once the temperature of the die is lowered by 30°C. This large hysteresis will
prevent it from generating motor boating sound and allow the device resume normal operation without the
need for external system interaction.
POP and Click Circuitry
The ft2011 includes circuitry to minimize turn-on and turn-off transients or “pops and clicks”. Here the
turn-on refers to either the application of the power supply or the device enabled by asserting SHDN high
and turn-off refers to either the removal of the power supply or the device shut down by pulling SHDN low.
When the device is first turned on, the amplifier is forced into mute mode initially. An internal current source
ramps up the internal reference voltage. The device will remain in the mute mode until the reference
voltage reaches to one half of the supply voltage, 1/2 VDD. As soon as the reference voltage reaches to a
value substantially close to its final value, the device will begin its normal operation. For the best power-off
pop performance, the amplifier should be placed in shutdown mode prior to removing the power supply
voltage.
Input Resistors (RI)
The input resistors (RI) set the gain of the amplifier according to Equation 1.
(1)
The matching of the input resistors is a crucial consideration for a fully differential amplifier. The balance of
the differential outputs with respect to the common-mode voltage strongly depends on the matching of the
input resistors. The CMRR, PSRR, and the cancellation of the even-order harmonics will be significantly
degraded if the mismatch of the input resist occurs. Therefore, it is recommended to use the resistors with
1% tolerance or better to keep the performance optimized. Note that the matching tolerance of the input
resistors is much more important than the absolute tolerance. Place the input resistors as close to the
ft2011 as possible to minimize the noise injected onto the high-impedance input nodes.
Decoupling Capacitor (CS)
The decoupling capacitor stabilizes the power supply voltage applied onto the ft2011, thus improving its
THD performance. It also prevents annoying voltage ringing with a long lead. A capacitor of 1µF or greater
with low equivalent-series-resistance (ESR) is required for decoupling and to be placed as close to the
ft2011 as possible to minimize the resistance and inductance of the traces between the device and the
capacitor. To filter out lower-frequency noise, a capacitor of 10µF or greater should be placed close to the
ft2011.
Input Capacitors (CI)
The input capacitors and input resistors determine the corner frequency of the highpass filter. The corner
frequency (fc) is calculated with the Equation 2.
(2)
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ft2011
The corner frequency directly influences the low frequency signals and consequently determines output
bass quality.
PCB Layout
As the output power increases, the interconnect resistance (PCB traces and wires) among the audio
amplifier, load, and power supply creates a voltage drop. The voltage loss on the traces between the ft2011
and the load results in lower output power and lower efficiency. The higher trace resistance between the
supply and the ft2011 has the same effect as a poorly regulated supply, increasing the voltage ripples on
the supply line and also reducing the peak output power. The effect of the residual trace resistance will be
intensified as the output current increases. To maintain the highest output voltage swing for a maximum
output power, the PCB traces that connect the output pins to the load and the supply pins to the power
supply should be as wide and short as possible to minimize trace resistance.
The use of power and ground planes will give the best THD+N performance. While reducing trace
resistance, the use of power planes also creates parasite capacitors that help filter the power supply line.
The inductive nature of the speakers can also result in overshoots on one or both edges, clamped by the
parasitic diodes to ground and VDD in each case. From an EMI standpoint, this is the highly unfavorable
waveform that will radiate or conduct to other components on the system board and cause interference. It is
essential to keep the power and output traces short and well shielded if possible. Use of ground planes,
beads, and micro-strip layout techniques are all useful in preventing unwanted interference.
As the distance from the ft2011 to the speaker increases, the amount of EMI radiation will increase since
the output wires or traces acting as antenna become more efficient with their lengths. What is acceptable
EMI is highly application specific. Ferrite bears placed close to the ft2011 may be needed to reduce EMI
radiation. The value of the ferrite bears is also application specific.
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ft2011
TYPICAL APPLICATION CIRCUITS
VDD
C5
Cs
+
47UF
1uF
1
2
3
4
8
7
6
5
CTRL
SHDN
NC
VON
GND
VDD
VOP
Rs
1.5Ω
LS
Single-Ended Input
C1 470nF
R1 22K
ft2011
INP
SPEAKER
C2
470nF
Cs
R2 22K
680pF~1nF
INN
INN
Figure 24: Single-Ended Audio Inputs (SOP-8L Package for Portable Speaker Application)
VDD
Cs
C3
+
1uF
47UF
Differential Inputs
C1 33nF
R1 47K
R2 47K
A1
C1
C2
INP
INN
INP
A3
C3
VON
VOP
LS1
C2 33nF
ft2011A
INN
SPEAKER
SHDN
SHDN
C1=C2, R1=R2
Gain=300K/R1
Figure 25: Differential Audio Input (COL-8L Package for Mobile Phone Application)
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ft2011
TYPICAL APPLICATION CIRCUITS (Cont’d)
Differential Input 1
VDD
C1 33nF
R1 47K
R2 47K
INP1
INN1
Cs
C5
+
C2 33nF
1uF
47UF
Differential Input 2
C3 33nF
INP2
R3 47K
R4 47K
A1
C1
C2
INP
A3
C3
VON
VOP
LS1
C4 33nF
INN2
ft2011A
INN
SPEAKER
SHDN
SHDN
C1=C2, R1=R2, C3=C4, R3=R4
Gain1=300K/R1, Gain2=300K/R3
Figure 26: Summing Two Differential Audio Inputs
VDD
C3
Cs
+
47UF
1uF
SHDN
L+R Inputs
1
2
3
4
8
7
6
5
SHDN
NC
VON
GND
VDD
VOP
R1 56K
R2 56K
R3 28K
C1
C2
C3
33nF
33nF
66nF
LS1
L-IN
ft2011M
R-IN
INP
SPEAKER
INN
C3=C1+C2, R3=R1*R2/(R1+R2)
Gain-L=300K/R1, Gain-R=300K/R2
Figure 27: Summing Two Single-Ended Audio Inputs (MSOP-8L Package for MID Application)
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ft2011
PHYSICAL DIMENSIONS
COL1.5X1.5-9L PACKAGE OUTLINE DIMENSIONS
b:0.250± 0.076
e:0.500
D:1.500± 0.076
L:0.250± 0.076
E:1.550± 0.050
d::0.250± 0.076
Top View
Bottom View
A1:0.000-0.050
A:0.550± 0.010
A3:0.152
Side View
All dimensions are in millimeters
Dimensions in Millmeters
Min. Max.
0.450/0.550 0.550/0.650 0.018/0.022 0.022/0.026
Dimensions in Inches
Symbol
Min. Max.
A
A1
A3
D
0.000
0.050
0.152REF.
0.000
0.002
0.006REF.
1.424
1.424
—
1.576
1.576
—
0.056
0.056
—
0.062
0.062
—
E
D1
E1
k
—
—
—
—
—
—
b
0.174
0.326
0.007
0.013
0.500TYP
0.020TRP.
e
L
d
—
0.174
—
0.326
—
0.007
—
0.013
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ft2011
PHYSICAL DIMENSIONS (Cont’d)
SOP-8 PACKAGE OUTLINE DIMENSIONS
θ1
θ3
h
θ
L
θ2
L1
θ4
D
INDEX
e
b
SYMBOL
MIN
1.35
0.10
1.25
0.50
0.38
0.17
4.80
5.80
3.80
NOM
1.55
0.15
1.40
0.60
-
MAX
UNIT
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
mm
A
A1
A2
A3
b
c
D
E
E1
e
1.75
0.25
1.65
0.70
0.51
0.25
5.00
6.20
4.00
-
4.90
6.00
3.90
1.27 (BSC)
0.60
1.04REF
0.25BSC
0.40
-
L
0.45
0.80
L1
L2
h
0.30
0
0.50
8°
θ
θ1
θ2
θ3
θ4
15°
11°
15°
11°
17°
13°
17°
13°
19°
15°
19°
15°
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ft2011
PHYSICAL DIMENSIONS (Cont’d)
MSOP-8 PACKAGE OUTLINE DIMENSIONS
D:3.00± 0.10
E1:3.00± 0.10
E:4.90± 0.20
B
B
e:0.65± 0.10
A3:0.35± 0.10
A2:0.85± 0.10
All dimensions are in millimeters
Dimensions in Millimeters
Symbol
A:0.00-1.10
Min.
—
Max.
1.10
0.15
0.95
0.39
0.37
0.33
0.20
0.16
3.10
5.10
3.10
0.75
0.80
A
A1
A2
A3
b
0
A1:0.00-0.15
0.75
0.25
0.28
0.27
0.15
0.14
2.90
4.70
2.90
0.55
0.40
WITH PLATING
BASE METAL
b1
c
c1
D
E
E1
e
c1:0.15± 0.01
c:0.175± 0.025
θ1:12° ± 3°
b1:0.30± 0.03
b:0.325± 0.045
L
R1
0.95REF.
0.25BSC.
L1
L2
R
R1
θ
θ1
R
0.07
0.07
0°
—
—
8°
15°
L2:0.25
L:0.60± 0.20
L1:0.95
θ:0° -8°
9°
θ1:12° ± 3°
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ft2011
PHYSICAL DIMENSIONS (Cont’d)
DFN2X2-8L PACKAGE OUTLINE DIMENSIONS
e:0.500
D:2.000± 0.100
L:0.350± 0.100
E1:0.600± 0.100
E:2.000± 0.100
D1:1.200± 0.100
b:0.24± 0.06
Top View
Bottom View
A1:0.000-0.050
A:0.800± 0.100
A3:0.203
Side View
All dimensions are in millimeters
Dimensions in Millimeters
Dimensions in Inches
Symbol
Min.
0.700/0.800
0.000
Max.
0.800/0.900
0.050
Min.
0.028/0.031
0.000
Max.
0.031/0.035
0.002
A
A1
A3
D
0.203REF
0.008REF
1.900
1.900
1.100
0.500
2.100
2.100
1.300
0.700
0.075
0.075
0.043
0.020
0.083
0.083
0.051
0.028
E
D1
E1
k
0.200MIN.
0.008MIN.
b
e
L
0.180
0.250
0.300
0.450
0.007
0.010
0.012
0.018
0.500TYP
0.020TYP.
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ft2011
IMPORTANT NOTICE
1. Disclaimer: The information in document is intended to help you evaluate this product. Fangtek, LTD.
makes no warranty, either expressed or implied, as to the product information herein listed, and reserves
the right to change or discontinue work on this product without notice.
2. Life support policy: Fangtek’s products are not authorized for use as critical components in life support
devices or systems without the express written approval of the president and general counsel of Fangtek
Inc. As used herein
Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and whose failure to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to
the user.
A critical component is any component of a life support device or system whose failure to perform can be
reasonably expected to cause the failure of the life support device or system, or to affect its safety or
effectiveness.
3. Fangtek assumes no liability for incidental, consequential or special damages or injury that may result
from misapplications or improper use or operation of its products
4. Fangtek makes no warranty or representation that its products are subject to intellectual property license
from Fangtek or any third party, and Fangtek makes no warranty or representation of non-infringement with
respect to its products. Fangtek specifically excludes any liability to the customer or any third party arising
from or related to the products’ infringement of any third party’s intellectual property rights, including
patents, copyright, trademark or trade secret rights of any third party.
5. The information in this document is merely to indicate the characteristics and performance of Fangtek
products. Fangtek assumes no responsibility for any intellectual property claims or other problems that may
result from applications based on the document presented herein. Fangtek makes no warranty with respect
to its products, express or implied, including, but not limited to the warranties of merchantability, fitness for
a particular use and title.
6. Trademarks: The company and product names in this document may be the trademarks or registered
trademarks of their respective manufacturers. Fangtek is trademark of Fangtek, LTD.
CONTACT INFORMATION
Fangtek Electronics (Shanghai) Co., Ltd
Room 503 & 504, Lane 198, Zhangheng Road
Zhangjiang Hi-tech Park, Pudong District
Shanghai, China, 201204
Tel: +86-21-61631978
Fax: +86-21-61631981
Website:
www.fangtek.com.cn
JAN, 2013
http://www.fangtek.com.cn
21
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