PAM8302L [PAM]
2.5W Filterless Class-D Mono Audio Amplifier; 2.5W无滤波D类单声道音频放大器
| 型号： | PAM8302L |
| 厂家： | 
POWER ANALOG MICOELECTRONICS |
| 描述： | 2.5W Filterless Class-D Mono Audio Amplifier |
| 文件： | 总13页 (文件大小：285K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Key Features
General Description
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Support 2.0V to 5.5V Supply Voltage Range
The PAM8302L is a 2.5W class-D mono audio
amplifier. Its low total harmonic distortion
(THD+N) offers high-quality sound reproduction.
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2.5W Output at 10% THD with a 4Ω Load
and 5V Power Supply
Filterless, Low Quiescent Current and Low
EMI
High Efficiency up to 88%
Superior Low Noise
Short Circuit Protection
Thermal Shutdown
Few External Components to Save Space
and Cost
MSOP-8 and DFN3x3 Packages Available
Pb-Free Package
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The PAM8302L uses a filterless design that
avoids the use of low-pass filters. This new design
allows the amplifier to directly drive a speaker,
making it cheap and compact. The new design
allows the amplifier to be more affordable and
take less PCB area.
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The PAM8302L uses less power than Class-AB
amplifiers. The use of this product can help
optimize battery life; it is ideal for portable
applications.
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Applications
The PAM8302L is available in MSOP-8
DFN3x3-8 packages.
and
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PMP/MP4
GPS
Portable Speakers
Walkie Talkie
Handsfree Phones/Speaker Phones
Cellular Phones
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Typical Application
1µF
6
VDD
Ci
Ci
Ri
Ri
4 IN-
IN-
VO-
8
5
Differential
Input
PAM8302L
IN+
SD
3
IN+
ON
VO+
1
OFF
GND
7
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
1
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Block Diagram
VDD
IN+
IN-
VO+
VO-
DRIVER
MODULATOR
THERMAL
PROTECTION
INTERNAL
OSCILLATOR
SHORT
PROTECTION
SHUTDOWN
SD
OSC
GND
Pin Configuration & Marking Information
Top View
DFN3x3-8
Top View
MSOP-8
1
8
7
6
5
VO-
SD
NC
IN+
IN-
SD
NC
IN+
IN-
1
2
3
4
8
7
6
5
VO-
X: Internal Code
2
3
GND
VDD
VO+
GND
VDD
VO+
P8302L
XXXXYW
Y: Year
W: Week
4
Pin Number
Pin name
Description
1
2
3
4
5
6
7
8
Shutdown terminal,active low
No connection
SD
NC
IN+
Positive differential input
Negative differential input
Positive BTL output
Analog power supply
Ground
IN-
VO+
VDD
GND
VO-
Negative BTL output
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
2
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Absolute Maximum Ratings
These are stress ratings only and functional operation is not implied. Exposure to absolute
maximum ratings for prolonged time periods may affect device reliability. All voltages are with
respect to ground.
Supply Voltage at no Input Signal...................6.0V
Input Voltage.............................-0.3V to VDD+0.3V
Maximum Junction Temperature..................150°C
Storage Temperature.....................-65°C to 150°C
Soldering Temperature.......................300°C,5sec
Recommended Operating Conditions
Supply voltage Range........................2.0V to 5.5V
Operation Temperature Range........ -40°Cto 85°C
Junction Temperature Range.........-40°C to 125°C
Thermal Information
Parameter
Package
Symbol
Maximum
Unit
MSOP-8
θJC
75
Thermal Resistance
(Junction to Case)
DFN3x3-8
MSOP-8
θJC
θJA
θJA
20
180
50
°C/W
Thermal Resistance
(Junction to Ambient)
DFN3x3-8
MSOP-8
PD
PD
550
Internal Power Dissipation
@ TA=25°C
mW
DFN3x3-8
2000
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
3
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Electrical Characteristics
VDD=5V, Gain = 24dB, RL=4Ω,TA=25°C，unless otherwise noted.
PARAMETER
Supply Voltage Range
Quiescent Current
SYMBOL
VDD
CONDITIONS
MIN
2.0
TYP
MAX
5.5
8
UNITS
V
IQ
No Load
4
mA
µA
Shutdown Current
ISHDN
VSHDN=0V
1
f=1kHz, RL=4Ω
THD+N=10%
f=1kHz, RL=4Ω
THD+N=1%
VDD=5V
2.25
2.50
1.25
2.00
0.95
1.50
0.80
1.30
0.65
85
VDD=3.6V
VDD=5V
1.10
1.80
0.86
1.35
0.72
1.15
0.6
VDD=3.6V
VDD=5V
Output Power
PO
W
f=1kHz, RL=8Ω
THD+N=10%
F=1kHz, RL=8Ω
THD+N=1%
VDD=3.6V
VDD=5V
VDD=3.6V
Peak Efficiency
η
f=1kHz
88
%
%
RL = 8Ω，PO=0.1W, f=1kHz
RL = 8Ω，PO=0.5W, f=1kHz
RL = 4Ω，PO=0.1W, f=1kHz
RL = 4Ω，PO=0.5W, f=1kHz
0.35
0.50
0.40
0.45
25.5
0.30
0.45
0.35
0.40
24
Total Harmonic Distortion Plus
Noise
THD+N
Gain
Gv
PSRR
Dyn
22.5
dB
dB
dB
dB
Power Supply Ripple Rejection
Dynamic Range
Signal to Noise Ratio
No input, f=1kHz, Vpp=200mV
f=20 to 20kHz
f =20 to 20kHz
45
85
75
50
90
80
SNR
No A-weighting
180
120
250
0.45
0.20
300
200
300
0.50
0.25
Noise
Vn
fOSC
µV
kHz
Ω
A-weighting
Oscillator Frequency
Drain-Source On-State
Resistance
200
P MOSFET
IDS=100mA
RDS(ON)
N MOSFET
VSH
VSL
1.2
V
V
SHDN Input High
0.4
SHDN Input Low
Over Temperature Protection
Over Temperature Hysteresis
OTP
OTH
junction temperature
120
135
30
°C
°C
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
4
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Typical Performance Characteristics
TA=25OC, unless otherwise noted.
THD+N VS Output Power
THD+N VS Output Power
RL=4Ω, Gain=23dB, f=1kHz
RL=8Ω, Gain=23dB, f=1kHz
50
50
V D D = 3 . 6 V
20
10
5
V D D = 3 . 6 V
V D D = 4 . 2 V
20
10
5
V D D = 4 . 2 V
%
%
2
1
2
1
0.5
0.5
V D D = 5 V
0.2
0.1
0.2
0.1
V D D = 5 V
20m
50m
100m
200m
500m
1
2
3
20m
50m
10m0
20m0
50m0
1
2
3
W
W
THD+N VS Frequency
RL=8Ω, Cin=0.1μF, Gain=23dB, VDD=3.6V
THD+N VS Frequency
RL=8Ω, Cin=0.1μF, Gain=23dB, VDD=5V
10
5
10
5
Po=200mW
2
2
1
1
0.5
Po=500mW
0.5
%
%
Po=500mW
0.2
0.1
0.2
0.1
0.05
Po=200mW
0.05
0.02
0.01
0.02
20
50
100
200
500
Hz
1k
2k
5k
10k 20k
20
50
100
200
500
Hz
1k
2k
5k
10k 20k
THD+N VS Frequency
RL=4Ω, Cin=0.1μF, Gain=23dB, VDD=5V
THD+N VS Frequency
RL=4Ω, Cin=0.1μF, Gain=23dB, VDD=3.6V
10
5
10
5
Po=200mW
2
2
1
1
Po=500mW
Po=200mW
0.5
0.5
%
%
Po=500mW
0.2
0.1
0.2
0.1
0.05
0.05
0.02
0.01
0.02
20
50
100
200
500
Hz
1k
2k
5k
10k 20k
20
50
100
200
500
Hz
1k
2k
5k
10k 20k
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
5
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Typical Performance Characteristics
TA=25OC, unless otherwise noted.
Quiescent Current VS Temperature
Frequency VS Temperature
No input, No Load, VDD=5.0V
No input, No Load, VDD=5.0V
8
350
300
250
200
150
100
50
7
6
5
4
3
2
1
0
0
0
50
100
Temperature
150
0
50
100
150
Temperature
Supply Current VS Output Power
VDD=5.0V
Supply Current VS Output Power
Rl=8Ω+33μH
0.4
0.35
0.3
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
0.25
0.2
0.15
0.1
Load=8ohm+33uH
L=4ohm+33uH
VDD=3.6V
0.05
0
VDD=5V
0
500
1000
1500
2000
0
500
1000
1500
2000
2500
3000
Output Power(mW)
Output Power(mW)
Output Power VS. Supply Voltage
Rl=8Ω
Output Power VS. Supply Voltage
Rl=4Ω
3.5
3
2.5
2
2.5
2
1.5
1
1.5
1
0.5
0
THD=1%
0.5
0
THD+N=1%
THD=10%
THD+N=10%
2.8
3
3.2 3.4 3.6 3.8
4
4.2 4.4 4.6 4.8
5
5.2 5.4
2.5
3
3.5
4
4.5
5
5.5
Supply Voltage(V)
Supply Voltage(V)
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
6
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Typical Performance Characteristics
TA=25OC, unless otherwise noted.
Efficiency VS Output Power
Efficiency VS Output Power
VDD=5.0V
Rl=8Ω+33μΗ
95%
95%
90%
85%
80%
75%
70%
65%
60%
90%
85%
80%
75%
70%
65%
60%
Load=8ohm+33uH
Load=4ohm+33uH
Vin=5V
Vin=3.6V
0
500
1000
1500
2000
0
500
1000
1500
2000
2500
3000
Output Power(mW)
Output Power(mW)
Quiescent Current VS. Supply Voltage
No load
Frequency VS. Supply Voltage
4.5
4
350
300
250
200
150
100
50
3.5
3
2.5
2
1.5
1
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)
Power Dissipation VS. Output Power
Rl=8Ω
0.16
0.14
0.12
0.10
0.08
0.06
0.04
0.02
0.00
VDD=5V
VDD=3.6V
0
500
1000
1500
2000
Output Pow er(W)
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
7
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Test Setup for Performance Testing
PAM8302L Demo Board
Load
AP
+OUT
Input
Low Pass
AP System
Analyzer
Audio Precision
(AP) System
Generator
Filter
-OUT
GND
AUX-0025
VDD
Power Supply
Notes
1. The Audio Precision(AP) AUX-0025 low pass filter is necessary for every class-D amplifier
measurement with AP analyzer.
2. Two 22µH inductors are used in series with load resistor to emulate the small speaker for
efficiency measurement.
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
8
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Application Information
Maximum Gain
capacitor is the best choice. When a polarized
capacitor is used, the positive side of the
As shown in block diagram (page 2), the
PAM8302L has two internal amplifier stages. The
first stage's gain is externally configurable, while
the second stage's is internally fixed. The closed-
loop gain of the first stage is set by selecting the
ratio of Rf to Ri while the second stage's gain is
fixed at 2x.The output of amplifier 1 serves as the
input to amplifier 2, thus the two amplifiers
produce signals identical in magnitude, but
different in phase by 180°. Consequently, the
differential gain for the IC is
capacitor should face the amplifier input in most
applications as the DC level is held at VDD/2,
which is likely higher than the source DC level.
Please note that it is important to confirm the
capacitor polarity in the application.
Power Supply Decoupling (Cs)
The PAM8302L is a high-performance CMOS
audio amplifier that requires adequate power
supply decoupling to ensure the output THD and
PSRR as low as possible. Power supply
decoupling affects low frequency response.
Optimum decoupling is achieved by using two
capacitors of different types that target different
types of noise on the power supply leads. For
higher frequency transients, spikes, or digital
hash on the line, a good low equivalent-series-
resistance (ESR) ceramic capacitor, typically
1.0µF is good, placing it as close as possible to
the device VDD terminal. For filtering lower-
frequency noise signals, a capacitor of 10µF or
AVD=20*log [2*(Rf/Ri)]
The PAM8302L sets maximum Rf=80kΩ, minimum
Ri=10kΩ, so the maximum closed-gain is 24dB.
Input Capacitors (Ci)
In typical application, an input capacitor, Ci, is
required to allow the amplifier to bias input
signals to a proper DC level for optimum
operation. In this case, Ci and the minimum input
impedance Ri (10k internal) form a high pass filter
with a corner frequency determined by the
following equation:
larger, closely located to near the audio power
amplifier is recommended.
Shutdown Operation
In order to reduce shutdown power consumption,
the PAM8302L contains shutdown circuitry for
turn off the amplifier. This shutdown feature turns
the amplifier off when a logic low is applied on the
SD pin. By switching the shutdown pin over to
GND, the PAM8302L supply current draw will be
minimized in idle mode.
It is important to choose the value of Ci as it
directly affects low frequency performance of the
circuit, for example, when an application requires
a flat bass response as low as 100Hz. Equation is
reconfigured as follows:
For the best power on/off pop performance,
the amplifier should be set in the shutdown
mode prior to power on/off operation.
As the input resistance is variable, for the Ci
value of 0.16μF, one should actually choose the
Ci within the range of 0.1μF to 0.22μF. A further
consideration for this capacitor is the leakage
path from the input source through the input
network (Ri, RF,Ci) to the load. This leakage
current creates a DC offset voltage at the input to
the amplifier that reduces useful headroom,
especially in high gain application. For this
reason, a low leakage tantalum or ceramic
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
9
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
How to Reduce EMI (Electro Magnetic Interference)
A simple solution is to put an additional capacitor 1000μF at power supply terminal for power line coupling
if the traces from amplifier to speakers are short (<20CM).
Most applications require a ferrite bead filter as shown at Figure 1. The ferrite filter depresses EMI of
around 1MHz and higher. When selecting a ferrite bead, choose one with high impedance at high
frequencies and low impedance at low frequencies.
Ferrite Bead
OUT+
220pF
Ferrite Bead
OUT-
220pF
Figure 1: Ferrite Bead Filter to reduce EMI
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
10
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Ordering Information
PAM8302L X X X X
Shipping Package
Number of pins
Package Type
Pin Configuration
Pin Configuration
Package Type
Number of pins
A:
S: MSOP
C: 8
Y: DFN3x3
1: SD
2: NC
3: IN+
4: IN-
5: VO+
6: VDD
7: GND
8: VO-
Part Number
PAM8302LASCR
PAM8302LAYCR
Package Type
MSOP-8
MOQ/Shipping Package
2,500 Units/Tape & Reel
3,000 Units/Tape & Reel
DFN3x3-8
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
11
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Outline Dimensions
MSOP-8
Millimeter
REF
Min
--
Max
1.10
0.15
0.94
0.38
0.23
3.10
3.10
5.05
A
A1
A2
b
0.05
0.78
0.22
0.08
2.90
2.90
4.75
c
D
E
E1
e
0.65BSC
L
0.40
0.70
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
12
PAM8302L
2.5W Filterless Class-D Mono Audio Amplifier
Outline Dimensions
DFN 3x3-8
DFN
Note: All dimensions are in Millimeters.
Power Analog Microelectronics,Inc
www.poweranalog.com
11/2010 Rev 1.0
13
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