US $0The PAM8403 sets maximum RF =142kΩ, minimum R =18kΩ, so the maximum closed-gain is 24dB. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8403

Super MiniPAM8403 DC 5V 2Channel USBDigital AudioAmplifier BoardModule 2 * 3WVolume ControlwithPotentionmeterSwitch

US$0.75/ piece

Price:

Product InformationPAM8403 is a small digital amplifier chip, high-definition sound quality highlights the advantages of digital chips, circuit usingthe most reasonable peripheral configuration, power supply filtering is upgraded to 470uf (some sellers are less did not even100uf capacitance) 1.6mm glass sheet, the real amplifier board did the most detailed, high-fidelity sound output 3W + 3W, is arare good product enthusiasts amplifier, potentiometer using original anti-meter body, life expectancy up to 15 years,potentiometer with switch can cut off the power supply directly counterclockwise, Listing has been received by the buyer! FeaturePower range: DC 2.5V – 5.5VMinimum Output: 3W * 2Dimensions: 29.5 * 20.2 * 15mm Noteplease make sure the power supply is not more than 5.5V and please don't do reverse polarity for "+" and "-", or else, it willburn the board.

PAM8403 Document number: DSxxxxx Rev. 1 - 4

1 of 11 www.diodes.com

November 2012© Diodes Incorporated

PAM8403

A Product Line ofDiodes Incorporated

FILTERLESS 3W CLASS-D STEREO AUDIO AMPLIFIER

Description

The PAM8403 is a 3W, class-D audio amplifier. It offers low THD+N,

allowing it to achieve high-quality sound reproduction. The new

filterless architecture allows the device to drive the speaker directly,

requiring no low-pass output filters, thus saving system cost and PCB

area.

With the same numbers of external components, the efficiency of the

PAM8403 is much better than that of Class-AB cousins. It can extend

the battery life, which makes it well-suited for portable applications. The PAM8403 is available in SOP-16 package.

Features

3W Output at 10% THD with a 4Ω Load and 5V Power Supply

Filterless, Low Quiescent Current and Low EMI

Low THD+N

Superior Low Noise

Efficiency up to 90%

Short Circuit Protection

Thermal Shutdown

Few External Components to Save the Space and Cost

Pb-Free Package

Pin Assignments

Applications

LCD Monitors / TV Projectors

Notebook Computers

Portable Speakers

Portable DVD Players, Game Machines

Cellular Phones/Speaker Phones

Typical Applications Circuit




PAM8403


Pin Descriptions

Pin

Number Pin

Name Function

1 +OUT_L Left Channel Positive Output

2 PGND Power GND

3 -OUT_L Left Channel Negative Output

4 PVDD Power VDD

5 MUTE Mute Control Input (active low)

6 VDD Analog VDD

7 INL Left Channel Input

8 VREF Internal analog reference, connect a bypass capacitor from VREF to GND.

9 NC No Connact

10 INR Right Channel Input

11 GND Analog GND

12 SHND Shutdown Control Input (active low)

13 PVDD Power VDD

14 -OUT_R Right Channel Negative Output

15 PGND Power GND

16 +OUT_R Right Channel Positive Output

Functional Block Diagram




PAM8403


Absolute Maximum Ratings (@TA = +25°C, unless otherwise specified.)

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.

Parameter Rating Unit

Supply Voltage 6.0 V

Input Voltage -0.3 to VDD +0.3V

Operation Temperature Range -40 to +85

°C

Maximum Junction Temperature 150

Operation Junction Temperature -40 to +125

Storage Temperature -65 to +150

Soldering Temperature 300, 5 sec

Recommended Operating Conditions (@TA = +25°C, unless otherwise specified.)

Parameter Rating Unit

Supply Voltage Range 2.5 to 5.5 V

Operation Temperature Range -40 to +85 °C

Junction Temperature Range -40 to +125 °C

Thermal Information

Parameter Package Symbol Max Unit

Thermal Resistance (Junction to Ambient) SOP-16 θJA 110 °C/W

Thermal Resistance (Junction to Case) SOP-16 θJC 23




PAM8403


Electrical Characteristics (@TA = +25°C, VDD = 5V, Gain = 24dB, RL = 8Ω, unless otherwise specified.)

Symbol Parameter Test Conditions Min Typ Max Units

VDD Supply Voltage 2.5 5.5 V

PO Output Power

THD+N = 10%, f = 1KHz, RL = 4Ω

VDD = 5.0V 3.2

W VDD = 3.6V 1.6

VDD = 3.2V 1.3

THD+N = 1%, f = 1KHz, RL = 4Ω

VDD = 5.0V 2.5

W VDD = 3.6V 1.3

VDD = 3.2V 0.85

THD+N = 10%, f = 1KHz, RL = 8Ω

VDD = 5.0V 1.8

W VDD = 3.6V 0.9

VDD = 3.2V 0.6

THD+N = 1%, f = 1KHz, RL = 8Ω

VDD = 5.0V 1.4

W VDD = 3.6V 0.72

VDD = 3.2V 0.45

THD+N Total Harmonic Distortion Plus Noise

VDD = 5.0V, PO = 1W, RL = 8Ω f = 1kHz

0.15 %

VDD = 3.6V, PO = 0.1W, RL = 8Ω 0.11

VDD = 5.0V, PO = 0.5W, RL = 4Ω f = 1kHz

0.15 %

VDD = 3.6V, PO = 0.2W, RL = 4Ω 0.11

GV Closed Loop Gain VDD = 3V to 5V 24 dB

PSRR Power Supply Ripple Rejection VDD = 5.0V, Inputs AC-Grounded with CIN = 0.47µF

f = 100Hz -59 dB

f = 1kHz -58

CS Crosstalk VDD = 5.0V, PO = 0.5W, RL = 8Ω,

GV = 20db f = 1kHz -95 dB

SNR Signal-to-Noise Ratio VDD = 5.0V, VORMS = 1V, GV = 20db f = 1kHz 80 dB

VN Output Noise VDD = 5.0V, Inputs AC-Grounded with CIN = 0.47µF

No A-Weighting 100 µV

A-Weighting 150

Dyn Dynamic Range VDD = 5.0V, THD = 1% f = 1kHz 90 dB

η Efficiency RL = 8Ω, THD = 10%

f = 1kHz 87

% RL = 4Ω, THD = 10% 83

IQ Quiescent Current

VDD = 5.0V

No Load

16

mA VDD = 3.6V 10

VDD = 3.0V 8

IMUTE Muting Current VDD = 5.0V VMUTE = 0.3V 3.5 mA

ISD Shutdown Current VDD = 2.5V to 5.5V VSD = 0.3V < 1 µA

RDS(ON) Static Drain-to-Source On-State Resistor

IDS = 500mA, VGS = 5V PMOS 180

mΩ NMOS 140

fSW Switching Frequency VDD = 3.0V to 5.0V 260 kHz

VOS Output Offset Voltage VIN = 0V, VDD = 5.0V 10 mV

VIH Enable Input High Voltage VDD = 5.0V 1.5 1.4 V

VIL Enable Input Low Voltage VDD = 5.0V 0.7 0.4

VIH MUTE Input High Voltage VDD = 5.0V 1.5 1.4 V

VIL MUTE Input Low Voltage VDD = 5.0V 0.7 0.4

OTP Over Temperature Protection No Load, Junction Temperature VDD = 5.0V

140 V

OTH Over Temperature Hysterisis 30 V




PAM8403


Typical Performance Characteristics (@TA = +25°C, unless otherwise specified.)




PAM8403


Typical Performance Characteristics (cont.) (@TA = +25°C, unless otherwise specified.)




PAM8403


Application Information

Application Note

1. When the PAM8403 works with LC filters, it should be connected with the speaker before it's powered on, otherwise it will be damaged easily. 2. When the PAM8403 works without LC filters, it's better to add a ferrite chip bead at the outgoing line of speaker for suppressing the possible electromagnetic interference. 3. The recommended operating voltage is 5.5V. When the PAM8403 is powered with four battery cells, it should be noted that the voltage of four new dry or alkaline batteries is over 6.0V, higher than its operation voltage, which will probably damage the device. Therefore, it's recommended to use either four Ni-MH (Nickel Metal Hydride) rechargeable batteries or 3 dry or alkaline batteries. 4. One should not make the input signal too large. Large signal can cause the clipping of output signal when increasing the volume. This will damage the device because of big gain of the PAM8403. 5. When testing the PAM8403 without LC filters by using resistor instead of speaker as the output load, the test results, e.g. THD or efficiency, will be worse than those of using speaker as load. Test Setup for Performance Testing

Notes: 1. The AP AUX-0025 low pass filter is necessary for 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. Maximum Gain As shown in block diagram (Page 2), the PAM8403 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

AVD = 20*log [2*(RF/RI)]

The PAM8403 sets maximum RF =142kΩ, minimum R =18kΩ, so the maximum closed-gain is 24dB. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8403. A logic low on this pin disables the outputs, and a logic high on this pin

enables the outputs. This pin may be used as a quick disable or enable of the outputs without a volume fade. Quiescent current is listed in the

electrical characteristic table. The MUTE pin can be left floating due to the internal pull-up. Shutdown Operation In order to reduce power consumption while not in use, the PAM8403 contains shutdown circuitry to turn off the amplifier's bias circuitry. This

shutdown feature turns the amplifier off when logic low is applied to the SHDN pin. By switching the SHDN pin connected to GND, the PAM8403

supply current draw will be minimized in idle mode. The SHDN pin can be left floating due to the internal pull-up.




PAM8403


Application Information (cont.)

Power Supply Decoupling The PAM8403 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 targeting to different types of noise on the power supply leads. For higher frequency transients, spikes, or digital hash on the line,

a good low equivalent-seriesresistance (ESR) ceramic capacitor, typically 1.0μF, works best, placing it as close as possible to the device VDD

terminal. For filtering lower frequency noise signals, a large capacitor of 20μF (ceramic) or greater is recommended, placing it near the audio

power amplifier. Input Capacitor (CI) Large input capacitors are both expensive and space hungry for portable designs. Clearly, a certain sized capacitor is needed to couple in low

frequencies without severe attenuation. But in many cases the speakers used in portable systems, whether internal or external, have little ability

to reproduce signals below 100Hz to 150Hz. Thus, using a large input capacitor may not increase actual system performance. In this case, input

capacitor (CI) and input resistance (RI) of the amplifier form a high-pass filter with the corner frequency determined by equation below,

CR2

1f

IIC

In addition to system cost and size, click and pop performance is affected by the size of the input coupling capacitor, CI. A larger input coupling

capacitor requires more charge to reach its quiescent DC voltage (nominally 1/2 VDD). This charge comes from the internal circuit via the

feedback and is apt to create pops upon device enable. Thus, by minimizing the capacitor size based on necessary low frequency response,

turn-on pops can be minimized. Analog Reference Bypass Capacitor (CBYP) The Analog Reference Bypass Capacitor (CBYP) is the most critical capacitor and serves several important functions. During start-up or recovery

from shutdown mode, CBYP determines the rate at which the amplifier starts up. The second function is to reduce noise caused by the power

supply coupling into the output drive signal. This noise is from the internal analog reference to the amplifier, which appears as degraded PSRR

and THD+N.

A ceramic bypass capacitor (CBYP) with values of 0.47μF to 1.0μF is recommended for the best THD and noise performance. Increasing the

bypass capacitor reduces clicking and popping noise from power on/off and entering and leaving shutdown. Under Voltage Lock-Out (UVLO) The PAM8403 incorporates circuitry designed to detect low supply voltage. When the supply voltage drops to 2.0V or below, the PAM8403

outputs are disabled, and the device comes out of this state and starts to normal function when VDD ≥ 2.2V.

The PAM8403 has short circuit protection circuitry on the outputs to prevent damage to the device when output-to-output or output-to-GND short

occurs. When a short circuit is detected on the outputs, the outputs are disabled immediately. If the short was removed, the device activates

again. Over Temperature Protection Thermal protection on the PAM8403 prevents the device from damage when the internal die temperature exceeds +140°C. There is a 15 degree

tolerance on this trip point from device to device. Once the die temperature exceeds the thermal set point, the device outputs are disabled. This

is not a latched fault. The thermal fault is cleared once the temperature of the die is reduced by 30°C. This large hysteresis will prevent motor

boating sound well and the device begins normal operation at this point without external system intervention.




PAM8403


Application Information (cont.)

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 in Figure 2. The ferrite filter reduces EMI of around 1 MHz and higher. When selecting a

ferrite bead, choose one with high impedance at high frequencies, and low impedance at low frequencies.

Figure 2: Ferrite Bead Filter to Reduce EMI

Ordering Information

Part Number Part Marking Package Type Standard Package

PAM8403DR PAM8403

XATYWWLL SOP-16 2500 Units/Tape&Reel

Marking Information




PAM8403


Package Outline Dimensions (All dimensions in mm.)

SOP-16




PAM8403


IMPORTANT NOTICE DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION). Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the application or use of this document or any product described herein; neither does Diodes Incorporated convey any license under its patent or trademark rights, nor the rights of others. Any Customer or user of this document or products described herein in such applications shall assume all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated website, harmless against all damages. Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel. Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized application. Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings noted herein may also be covered by one or more United States, international or foreign trademarks. This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the final and determinative format released by Diodes Incorporated.

LIFE SUPPORT Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express written approval of the Chief Executive Officer of Diodes Incorporated. As used herein: A. Life support devices or systems are devices or systems which: 1. are intended to implant into the body, or

2. 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 significant injury to the user.

B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or to affect its safety or effectiveness. Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems. Copyright © 2012, Diodes Incorporated www.diodes.com

Key Features

Applications

3W Output at 10% THD with a 4 Load and5V Power SupplyFilterless, Low Quiescent Current and LowEMILow THD+NSuperior Low NoiseEfficiency up to 90%Short Circuit ProtectionThermal ShutdownFew External Components to Save theSpace and Cost

LCD Monitors / TV ProjectorsNotebook ComputersPortable SpeakersPortable DVD Players, Game MachinesCellular Phones/Speaker Phones

directlysystem cost

It can extend the battery life,ideal for portable applications.

Ω

General Description

The PAM8403 is a 3W, class-D audio amplifier. Itoffers low THD+N, allowing it to produce high-quality sound reproduction. The new filterlessarchitecture allows the device to drive the speaker

, without needing low-pass output filterswhich will save the and PCB area.

With the same numbers of external components,the efficiency of the PAM8403 is much better thanclass-AB cousins.

The PAM8403 is available in a DIP-16 and SOP-16 packages.

,

Pb-Free Package

Typical Application

PAM8403Filterless 3W Class-D Stereo Audio Amplifier

1

English:www.poweranalog.com www.power-analog.com：

0

10

20

30

40

50

60

70

80

90

100

0 0.5 1 1.5 2 2.5 3

Output Pow er(W)

Effic

iency(%

) RL=8ΩRL=4Ω

Efficiency vs Output Power

-OUT_L

PGND PGND

+OUT_L

+OUT_R

-OUT_R

PVDD PVDD

SHDN

VDD

GND

INL

INR

VREF

1

3

14

16

1uF 1uF 1uF470uF

VDD PVDD6 4 1

3

7

10

0.47uF

0.47uF

12

8

1uF

9 2 1511

INL

INR PAM8403

MUTE

GND

5

SHDN

MUTE

Ri

Ri

FCC Class B Limit

Radiated Emissions

03/2007

,Power Analog Microelectronics Inc

Block Diagram

2

Pin Configuration & Marking Information


VDD/2

VDD/2

Inte

rfa

ce

Co

ntr

ol

Atte

nu

atio

nD

eco

de

r

VDD

INR

MUTE

SHDN

INL

GND PVDD PGND

-OUT_L

+OUT_L

VREF

-OUT_R

+OUT_R

PGNDPVDD

MODULATORDRIVER

INTERNALOSCILLATOR

OSC

BIASANDREFERENCES

MODULATORDRIVER

ThermalProtection

CurrentProtection

+

-

+

-

X: Internal CodeA: Assembly CodeT: Testing CodeY: Year

WW: WeeklyLL: Internal Code


Top ViewDIP-16

PA

M8

40

3X

AT

YW

WL

L

1

2

3

4

5

6

7

8 9

10

11

12

13

14

15

16

03/2007


Top ViewSOP-16

PA

M8

40

3X

AT

YW

WL

L

1

2

3

4

5

6

7

8 9

10

11

12

13

14

15

16

Pin Number Pin Name Description

1 -OUT_L Left Channel Negative Output

2 PGND Power GND

3 +OUT_L Left Channel Positive Output

4 PVDD Power VDD

5 MUTE Mute Control Input（active low）

6 VDD Analog VDD

7 INL Left Channel Input

8 VREFInternal analog reference, connect a bypass capacitor from

VREF to GND

9 GND Analog GND

10 INR Right Channel Input

11 GND Analog GND

12 SHDN Shutdown Control Input(active low)

13 PVDD Power VDD

14 +OUT_R Right Channel Positive Output

15 PGND Power GND

16 -OUT_R Right Channel Negative Output


3


Pin Descriptions

Absolute Maximum RatingsThese are stress ratings only and functional operation is not implied Exposure to absolutemaximum ratings for prolonged time periods may affect device reliability All voltages are withrespect to ground

.

.

.

Supply Voltage ...........................................5.5VOperation Temperature Range...........-40 to 85

Operation Junction Temperature......-40 to 125Storage Temperature......................-65 to 150Soldering Temperature........................

.

Maximum Junction Temperature..................150 300 ,5sec

Recommended Operating ConditionsSupply voltage Range..........................Operation Temperature Range...........-40 to 85

Junction Temperature Range...........-40 to 1252.5V to 5V

Thermal Information

03/2007

Parameter Symbol Package Maximum Unit

DIP-16 90Thermal Resistance (Junction to Ambient) θJA

SOP-16 110/W


PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range VDD 2.5 5 V

No Load 10 15

RL=8Ω 11Quiescent Current IQ

RL=4Ω 12

mA

Mute Current IMUTE VMUTE=0V 1.5 3 mA

Shutdown Current ISHDN VSHDN=0V 45 100 uA

SHDN Input High VSH 1.2

SHDN Input Low VSL Note 2 0.5V

MUTE Input High VMH 1.2

MUTE Input Low VML Note 3 0.5V

Output Offset Voltage VOS No Load 10 30 mV

P MOSFET 0.3 0.40Drain-Source On-State

ResistanceRDS(ON) IDS=0.5A

N MOSFET 0.22 0.35Ω

RL= 8Ω 1.55 1.7Output Power PO

THD+N=10%,

1kHz RL= 4Ω 2.85 3.0W

RL = 8Ω，PO=0.25W 0.08

RL = 8Ω，PO=1.1W 0.27 1.0

RL = 4Ω，PO=0.35W 0.08

Total Harmonic Distortion Plus

NoiseTHD+N

RL= 4Ω，PO=2.0W 0.3 1.0

%

Power Supply Ripple Rejection PSRR No input, f=1KHz, Vpp=200mV 45 55 dB

Channel Separation CS PO=1W, RL=4Ω 60 80 dB

Oscillator Frequency fOSC PO=1W, RL=8Ω 250 350 450 kHz

PO=1.7W,f=1kHz, RL=8Ω 85 89 %Efficiency η

PO=3.0W,f=1kHz, RL=4Ω 80 83 %

RL=4Ω 65 80 dBSignal Noise Ratio SNR f =20 to 20KHz

RL=8Ω 65 80 dB

Over Temperature Protection OTP 120

Over Temperature Hysteresis OTH 40

4

Electrical CharacteristicV =5V, Gain = 18.5dB, R =8 Note 1 T =25 unless otherwise noted.DD L AΩ( ), ，


Note 1: All the loads here are delicate to use for speaker.Note 2:Note 3: Grounded or <0.9V to Mute

Grounded or <0.9V to Shutdown


03/2007


5

Typical Operating Characteristics(T =25°C)A


1. THD+N vs Output Power

V =5V, R =4 , Gain = 18.5dBDD L Ω


V =5V, R =8 , Gain = 18.5dBDD L Ω


V =5V, R =4 , P =0.8W,Gain = 18.5dBDD L OΩ



0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20m 450m 100m 200m 500m 1 2

W

V =5VDD

V =2.5VDD

V =3.3VDD

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20m 450m 100m 200m 500m 1 2

W

V =5VDD

V =2.5VDD

V =3.3VDD

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20m 450m 100m 200m 500m 1 2

W

f=100Hz

f=10KHz

f=1KHz

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20m 450m 100m 200m 500m 1 2

W

f=100Hzf=10KHz

f=1KHz

5. THD+N vs Frequency

V =5V, R =4 ,Gain = 18.5dBDD L Ω

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20 20k50 100 200 500 1k 2k 5k 10k

Hz

Po=2WPo=1.5W

Po=2W

6. THD+N vs Frequency

V =5V, R =8 ,Gain = 18.5dBDD L Ω

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20 20k50 100 200 500 1k 2k 5k 10k

Hz

Po=2WPo=0.5W

Po=1W


03/2007


6

Typical Operating Characteristics(continued)


11. FFT of Noise Output

-150

+0

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

d

B

V

20 20k50 100 200 500 1k 2k 5k 10k

Hz

V =5V, Gain = 18.5dBDD

12.Channel Separation


-110

-40

-100

-90

-80

-70

-60

-50

d

B

20 20k50 100 200 500 1k 2k 5k 10k

Hz

R to L

L to R

9. Frequency response

V =5V, Gain =18.5dBDD

10. Power Supply Ripple Rejection VS Frequency

-70

+20

-60

-50

-40

-30

-20

-10

+0

+10

d

B

10 20k20 50 100 200 500 1k 2k 5k 10k

Hz

V =5V with 200mVpp RippleDD

+15

+35

+20

+25

+30

d

B

r

20 20k50 100 200 500 1k 2k 5k 10k

HzHz

7. THD+N vs. Frequency

Po=0.1W,R =8 Gain=18.5dBL Ω,Po=0.8W,R =4 Gain=18.5dBL Ω,

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20 20k50 100 200 500 1k 2k 5k 10k

Hz

V =5VDD

V =3.3VDD

8. THD+N vs. Frequency

0.01

100

0.02

0.05

0.1

0.2

0.5

1

2

5

10

20

50

%

20 20k50 100 200 500 1k 2k 5k 10k

Hz

V =5VDD

V =3.3VDD


03/2007


Notes

1. The AP AUX-0025 low pass filter is necessary for every class-D amplifier measurementdone by AP analyzer.

2. Two 22uH inductors are used in series with load resistor to emulate the small speaker forefficiency measurement.

7

Application Notice

1. When the PAM8403 works with LC filters, itshould be connected with the speaker before it'spowered on, otherwise it will be damaged easily.

2. When the PAM8403 works without LC filters,it's better to add a ferrite chip bead at theoutgoing line of speaker for suppressing thepossible electromagnetic interference.

3. The absolute maximum rat ing of thePAM8403 operation voltage is 5.5V. When thePAM8403 is powered with 4 battery cells, it'sworth noting that the voltage of 4 new dry oralkaline batteries is over 6V, higher than itsmaximum operation voltage, which will probably

make the device damaged. Therefore, it 'srecommended to use either 4 Ni-MH (NickelMetal Hydride) rechargeable batteries or 3 dry oralkaline batteries.

4. It should not make the input signal too high,which will cause the clipping of output signalwhen increasing the volume. Because the digitalvolume control of the PAM8403 has big gain, itwill make the device damaged.

5. When testing the PAM8403 without LC filtersby using resistor instead of speaker as the outputload, the test results, e.g. THD or efficiency, willbe worse than those of using speaker as load.


Test Setup for Performance Testing

AP System One

Generator

PAM8403 Demo Board

+OUT

Input

Load

AP

Low Pass

Filter

AUX-0025

AP System One

Analyzer

GND -OUT

VDD

Power Supply


03/2007


Maximum Gain

Mute Operation

As shown in block diagram(page 2),the PAM8403has two internal amplifiers stage. The firststage's gain is externally configurable, while thesecond stage's is internally fixed in a fixed-gain,inverting configuration. The closed-loop gain ofthe first stage is set by selecting the ratio of R to

R while the second stage's gain is fixed at

1.4x.The output of amplifier one serves as theinput to amplifier two which results in bothampl i f ie rs produc ing s igna ls iden t ica l inm a g n i t u d e , b u t o u t o f p h a s e b y 1 8 0 ° .Consequently, the differential gain for the IC is

A =20*log [2*(R /R )*1.4]

The PAM8403 sets maximum R =85K , minimum

R =15K , so the maximum closed-gain is 24dB.

The pin is an input for controlling theoutput state of the PAM8403. A logic low on thispin disables the outputs, and a logic high on thispin enables the outputs. This pin may be used asa quick disable or enable of the outputs without avolume fade. Quiescent current is listed in theelectrical characteristic table. The pin canbe left floating due to the pull-up internal.

f

i

VD f i

f

i

Ω

Ω

MUTE

MUTE

Shutdown operation

Power supply decoupling

Input Capacitor (C )

Analog Reference Bypass Capacitor (C )

In order to reduce power consumption while notin use, the PAM8403 contains shutdown circuitrythat is used to turn off the amplifier's biascircuitry. This shutdown feature turns theamplifier off when logic low is placed on the

pin. By switching the pin connectedto GND, the PAM8403 supply current draw will beminimized in idle mode. The pin can be leftfloating due to the pull-up internal.

The PAM8403 is a high performance CMOSaudio amplifier that requires adequate powersupply decoupling to ensure the output THD andPSRR are as low as possible. Power supplydecoupling is affecting low frequency response.Optimum decoupling is achieved by using twocapacitors of different types that target differenttypes of noise on the power supply leads. Forhigher frequency transients, spikes, or digital

hash on the line, a good low equivalent-series-resistance (ESR) ceramic capacitor, typically1.0μF, placed as close as possible to the deviceV terminal works best. For filtering lower-

frequency noise signals, a larger capacitor of20μF(ceramic) or greater placed near the audiopower amplifier is recommended.

Large input capacitors are both expensive andspace hungry for portable designs. Clearly, acertain sized capacitor is needed to couple in lowfrequencies without severe attenuation. But inmany cases the speakers used in portablesystems, whether internal or external, have littleability to reproduce signals below 100Hz to150Hz. Thus, using a large input capacitor maynot increase actual system performance. In thiscase, input capacitor (C ) and input resistance

(R ) of the amplifier form a high-pass filter with

the corner frequency determined equation below,

In addition to system cost and size, click and popperformance is affected by the size of the inputcoupling capacitor, C . A larger input coupling

capacitor requires more charge to reach itsquiescent DC voltage (nominally 1/2 V ). This

charge comes from the internal circuit via thefeedback and is apt to create pops upon deviceenable. Thus, by minimizing the capacitor sizebased on necessary low frequency response,turn-on pops can be minimized.

The Analog Reference Bypass Capacitor (C ) is

the most critical capacitor and serves severalimportant functions. During start-up or recoveryfrom shutdown mode, C determines the rate at

which the amplifier starts up. The secondfunction is to reduce noise produced by thepower supply caused by coupling into the outputdrive signal. This noise is from the internalanalog reference to the amplifier, which appearsas degraded PSRR and THD+N.

Bypass capacitor (C ) values of 0.47μF to

1.0μF ceramic is recommended for the best THDand noise performance. Increasing the bypasscapacitor reduces clicking and popping noise

SHDN SHDN

SHDN

DD

i

i

i

DD

BYP

BYP

BYP

i

BYP

8


Application Information


C

i i

1f =

2πRC

03/2007


from power on/off and entering and leavingshutdown.

Thermal protection on the PAM8403 preventsdamage to the device when the internal dietemperature exceeds 120 . There is a 15 degreetolerance on this trip point from device to device.Once the die temperature exceeds the thermalset point, the device outputs are disabled. This isnot a latched fault. The thermal fault is clearedonce the temperature of the die is reduced by40 . This large hysteresis will prevent motorboating sound well and the device begins normaloperation at this point with no external systeminteraction.

Figure 3: Ferrite Bead Filter to reduce EMI

Over Temperature Protection

Power On/Off Pop noise Reducing

Under Voltage Lock-out (UVLO)

Short Circuit Protection (SCP)

How to Reduce EMI (E lect ro Magnet icInterference)

Power on pop noise reducing: The PAM8403contains circuitry to minimize turn-on pop noise.In this case, turn-on refers to either power supplyturn-on or device coming out shutdown mode.When the device is turning on, the amplifiers areinternally muted. An internal current sourceramps up the voltage of VREF pin. The device willremain in mute mode until the VREF pin hasreached its half supply voltage, 1/2 V . As soon

as the VREF node is stable, the device willbecome fully operational.

Power off pop noise reducing: for the best power-off pop performance, the amplifier should beplaced in the mute /shutdown mode prior toremoving the power supply voltage. An externalcircuit shows in figure 2 also can minimize thepower off pop noise: the V is set around

1.3V@V =5V which is a little higher than the

mute/shutdown threshold voltage, R1 reduce theinternal resistor temperature coefficient andcapacitor C speeds up the response. Note thatthis circuit can only work in between V = 4.5V to

5.5V, otherwise the PAM8403 can not work, otherthan the ratio of the resistor divider needs to bechanged.

Figure 2: External Circuit to reduce power off popnoise

The PAM8403 incorporates circuitry designed todetect when the supply voltage is low. When thesupply voltage drops to 2.0V or below, thePAM8403 outputs are disable, and the devicecomes out of this state and starts to normalfunctional until V 2.2V.

The PAM8403 has short circui t protect ioncircuitry on the outputs that prevents damage tothe device during output-to-output and output-to-GND short. When a short circuit is detected on theoutputs, the outputs are disable immediately. Ifthe short was removed, the device activatesagain.

A simple solution is to put an additional capacitor1000uF at power supply terminal for power linecoupling if the traces from amplifier to speakersare short (<20CM).

Most applications require a ferrite bead filterwhich shows at Figure 3. The ferrite filter reducesEMI around 1 MHz and higher. When selecting aferrite bead, choose one with high impedance athigh frequencies, but low impedance at lowfrequencies.

DD

TH

DD

DD

DD ≥

9


Application Information(continued)


C

1nFR147K

R210K

VDD

VTHMUTE or SHDN

200pF

200pF

OUT+

OUT-

Ferrite Bead

Ferrite Bead

03/2007


Please consult PAM sales office or authorized Rep Distributor for detailed ordering information../

Ordering Information

10


Package Type

PAM8403 X X

Shipping


03/2007

Part Number Marking Package Type Standard Package

PAM8403QTPAM8403

XATYWWLLDIP-16 30 Units/Tube

PAM8403DTPAM8403

XATYWWLLSOP-16 50 Units/Tube

PAM8403DRPAM8403

XATYWWLLSOP-16 2,500 Units/Tape&Reel


11



Outline DimensionH

A2

AA1

0.1

00

typ

.0

.01

8ty

p.

0.0

60

typ

.

L

D

E1

E

eθθ

ο

DIP-16

Symbols MIN TYP MAX

A - - 0.210

A1 0.015 - -

A2 0.125 - -

D 0.735 0.755 0.775

E 0.300 BSC.

E1 0.245 0.250 0.255

L 0.115 0.130 0.150

eθ 0.335 0.355 0.375

θo

0 7 15

Unit: Inch

03/2007



12



Outline Dimension

03/2007

D

EE1

e

A2

B A1

A

C

L

θ

Dimensions MillimetersSymbol

Min Max

A 1.350 1.750

A1 0.100 0.250

A2 1.350 1.550

B 0.330 0.510

C 0.190 0.250

D 9.800 10.000

E 3.800 4.000

E1 5.800 6.300

e 1.270(TYP)

L 0.400 1.270

θ 0º 8º

SOP-16

Documents

US $0The PAM8403 sets maximum RF =142kΩ, minimum R =18kΩ, so the maximum closed-gain is 24dB. Mute Operation The MUTE pin is an input for controlling the output state of the PAM8403