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PAM8303D datasheet

Key Features

Applications

Ultra Low EMI,-20dB Better Than FCC

Class-B @300MHz

High Efficiency up to 90%@1W with an 8Speaker

Shutdown Current <1A

3W@10%THD Output with a 4Load at 5V

Supply

Demanding Few External Components Superior Low Noise without Input Supply Voltage from 2.8V to 5.5V Short Circuit Protection Thermal Shutdown

Available in Space Saving Packages:

1.45mmx1.45mm WCSP9,MSOP-8,DFN 3x3Cellular Phones/Smart Phones MP4/MP3GPS

Digital Photo Frame Electronic Dictionary

Portable Game Machines

μΩn n n n n n

General Description

The PAM8303D is a 3W mono filterless class-D amplifier with high PSRR and differential input that eliminate noise and RF rectification.

Features like 90%efficiency and small PCB area make the PAM8303D class-D amplifier ideal for cellular handsets.The filterless architecture requires no external output filter,fewer external components,less PCB area and lower system costs,and simplifies application design.

The PAM8303D features short circuit protection and thermal shutdown.

The PAM8303D is available in 9-ball WCSP,MSOP-8and DFN 3x38-pin packages.

n n n n n n n n n n n Pb-Free Package

Typical Application Circuit

EMI vs Frequency

Level dBuV m (/)

FCC

Class B

()

MHz IN

Input

Block Diagram

PVDD OUT+

GND

Pin Configuration &Marking Information

234

678

MSOP-8Top View

P8303D XXXXYW

1234

678

P8303D XXXXYW

DFN Top View

X:Internal Code Y:Year W:Week

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 ...........................................6.6V Input Voltage.............................-0.3V to V +0.3V Junction Temperature....................-40to 125Storage Temperature.....................-65°C to 150Soldering Temperature.....................DD °C °C

°C 250°C,10sec

Recommended Operating Conditions

Supply voltage Range........................Ambient Operation Temperature.......-20to 852.8V to 5.5V Max.Supply Voltage (for Max.duration of

30minutes)................................................6.4V

°C °C

Thermal Information

Note :For the 9-pin CSP package,the thermal resistance is highly dependent on the PCB heat sink area.For example,the can equal to 195/W with 50mm total area or 135/W with 500mm area.When using ground and power planes,the value is around 90/W.

θja 22°C °C °C

Electrical Characteristic

T =25C,A °V =5V,Gain=2V/V,R =L(33H)+R+L(33H),unless otherwise noted DD L μμ.

(To Be Cont’d)

Electrical Characteristic(continued)

T=25C,V=5V,Gain=2V/V,R=L(33H)+R+L(33H),unless otherwise noted °μμ.

A DD L

Typical Operating Characteristics

T =25C,V =5V,Gain=2V/V,unless otherwise noted A DD °.

f=1kHz,01020304050607080901000

0.5

1.5

Output P ow er (W)

E f f i c i e n c y (%)

1.Efficiency VS Output Power

2.Efficiency VS Output Power

1020304050607080901000

0.5

1.5

2.5

Output Pow er (W)

E f f i c i e n c y (%)

4.THD+N VS Output Power

Audio Precision

30m

50m

100m

200m

500m

3.THD+N VS Output Power

10m

20m

50m

100m

200m 500m

5.THD+N VS Frequency

7.THD+N VS

Frequency

8.THD+N VS Frequency

20k

100

200

500

10k

Typical Operating Characteristics

T =25C,V =5V,Gain=2V/V,unless otherwise noted A DD °.

f=1kHz,

9.Frequency Response

10.PSRR VS Frequency

-8

-3-7-7-6-6-5-5-4-4-3d B r A

20k

501002005001k 2k 5k 10k H z

d B

100k

20501002005001k 2k 5k 10k 20k 50k H z

d B r A

20k 501002005001k 2k 5k 10k Hz

-15+-14-13-12-11-10-9-8-7-6-5-4-3-2-1d B r A

H z

Typical Operating Characteristics

T =25C,V =5V,Gain=2V/V,unless otherwise noted A DD °.

f=1kHz,

3.5

4.5

5 5.5

Quiescent C urrent (m A)

68101200.20.4

0.60.8

Shutdow n Voltage (V)

S h u t d o w n C u r r e n t (u A )

00.5

1.5

2.5

3.5

4.5

5.5

Supply Voltage (V)

O u t p u t P o w e r (

V )

15.Output Power vs Supply Voltage

00.5

11.522.53

3.5

4.5

Supply Voltage (V)

O u t p u t P o w e r (W )

Typical Operating Characteristics

T =25C,V =5V,Gain=2V/V,unless otherwise noted A DD °.

f=1kHz,

17.OSC Frequency

100

120140160180200220240

2602803003

3.5

4.5

Supply Voltage (V)

R d s o n (m Ω)

18.Rdson vs Supply Voltage

19.Start-up from Shutdown

Output

200

210220230240250260270280

2903002.7

3.4

4.1

4.8

5.5

Supply Voltage (V)

F r e q u e n c y (K H z )

Typical Operating Characteristics

T =25C,V =5V,

Gain=2V/V,unless otherwise noted A DD °.

f=1kHz,Notes

1.The AP AUX-0025low 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.

Test Setup for Performance Testing

PAM8303D Demo Board

Input Resistance (Ri)

Input Capacitors (Ci )

Decoupling Capacitor (C )

How to Reduce EMI

The input resistors (Ri)set the gain of the amplifier according to Equation 1.

Resistor matching is very important in fully

differential amplifiers.The balance of the output on the reference voltage depends on matched ratios of the resistors.CMRR,PSRR,and cancellation of the second harmonic distortion diminish if resistor mismatch occurs.Therefore,it is recommended to use 1%tolerance resistors or better to keep the performance optimized.Matching is more important than overall tolerance.Resistor arrays with 1%matching can be used with a tolerance greater than 1%.Place the input resistors very close to the PAM8303D to limit noise injection on the high-impedance nodes.

For optimal performance the gain should be set to 2X(Ri=150k)or lower.Lower gain allows the PAM8303D to operate at its best,and keeps a high voltage at the input making the inputs less susceptible to noise.In addition to these features,higher value of Ri minimizes pop noise.In the typical application,an input capacitor,Ci,is required to allow the amplifier to bias the input signal to the proper DC level for optimum operation.In this case,Ci and the minimum input impedance Ri form is a high-pass filter with the corner frequency determined in the follow equation:It is important to consider the value of Ci as it directly affects the low frequency performance of the circuit.For example,when Ri is 150k and the specification calls for a flat bass response are down to 150Hz.Equation is reconfigured as followed:

When input resistance variation is considered,the Ci is 7nF,so one would likely choose a value of 10nF.A further consideration for this capacitor is the leakage path from the input source through the input network (,)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 applications.

For this reason,a low-leakage tantalum or ceramic capacitor is the best choice.When polarized capacitors are used,the positive side of the capacitor should face the amplifier input in most applications as the DC level is held at V /2,which is likely higher than the source DC level.Please note that it is important to confirm the capacitor polarity in the application.The PAM8303D is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to ensure the output total harmonic distortion (THD)as low as possible.Power supply decoupling also prevents the oscillations causing by long lead length between the amplifier and the speaker.

The optimum decoupling is achieved by using two different types of capacitors that target on 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 1F,is placed as close as possible to the device each VDD and PVDD pin for the best operation.For filtering lower frequency noise signals,a large ceramic capacitor of 10F or greater placed near the audio power amplifier is recommended.Most applications require a ferrite bead filter for EMI elimination shown at Figure 1.The ferrite filter reduces EMI around 1MHz and higher.When selecting a ferrite bead,choose one with high impedance at high frequencies,but low impedance at low frequencies.

Figure 1:Ferrite Bead Filter to Reduce EMI ΩμDD S Ci Ri +Rf In order to reduce power consumption while not in use,the PAM8303D contains shutdown circuitry that is used to turn off the amplifier’s bias circuitry.This shutdown feature turns the

μShutdown operation

Application Information

2150k V Gain Ri V ′W ??

=?÷

è?()C 1

f 2RiCi p =

()

i c 1

Ci 2R f p =

amplifier off when logic low is placed on the pin.By switching the shutdown pin connected to GND,the PAM8303D supply current draw will be minimized in idle mode.

°C internal associated (VDD and PVDD)(10F or greater)Output filter -The ferrite EMI filter should be placed as close to the output terminals as possible for the best EMI performance,and the capacitors used in the filters should be grounded to system ground.

SD μUnder Voltage Lock-out (UVLO)

Short Circuit Protection (SCP)

Over Temperature Protection (OTP)

POP and Click Circuitry

PCB Layout Guidelines Grounding

Power Supply Line

Components Placement

The PAM8303D incorporates circuitry designed to detect low supply voltage.When the supply voltage drops to 2.3V or below,the PAM8303D goes into a state of shutdown,and the device comes out of its shutdown state and restore to normal function only when reset the power supply or pin.

The PAM8303D has short circuit protection circuitry on the outputs to prevent the device from damage when output-to-output shorts or output-to-GND shorts occur.When a short circuit occurs,the device immediately goes into shutdown state.Once the short is removed,the device will be reactivated.

Thermal protection on the PAM8303D prevents the device from damage when the internal die temperature exceeds 135°C.There is a 15tolerance on this trip point from device to device.Once the die temperature exceeds the set point,the device will enter the shutdown state and the outputs are disabled.This is not a latched fault.T h e t h e r m a l f a u l t i s c l e a r e d o n c e t h e temperature of the die decreased by 30.This large hysteresis will prevent motor boating sound well and the device begins normal operation at this point with no external system interaction.The PAM8303D contains circuitry to minimize turn-on and turn-off transients or “click and pops”,where turn-on refers to either power supply turn-on or device recover from shutdown mode.When the device is turned on,the amplifiers are internally muted.An internal current source ramps up the reference voltage.The device will remain in mute mode until the reference voltage reach half supply voltage,1/2VDD.As soon as the reference voltage is stable,the device will begin full o p e r a t i o n.F o r t h e b e s t p o w e r -o f f p o p performance,the amplifier should be set in shutdown mode prior to removing the power supply voltage.

It is recommended to use plane grounding or s e p a r a t e g r o u n d s.D o n o t u s e o n e l i n e connecting power GND and analog GND.Noise currents in the output power stage need to be returned to output noise ground and nowhere else.When these currents circulate elsewhere,they may get into the power supply,or the signal ground,etc,even worse,they may form a loop and radiate noise.Any of these instances results in degraded amplifier performance.The output noise ground that the logical returns for the output noise currents with class D switching must tie to system ground at the power exclusively.Signal currents for the inputs,reference need to be returned to quite ground.This ground only ties to the signal components and the GND pin.GND then ties to system ground.

As same to the ground,VDD and PVDD need to be separately connected to the system power supply.It is recommended that all the trace could be routed as short and thick as possible.For the power line layout,just imagine water stream,any barricade placed in the trace (shown in figure 2)could result in the bad performance of the amplifier.

Figure 2:Power Line

Decoupling capacitors-As previously described,the high-frequency 1F decoupling capacitors should be placed as close to the power supply terminals as https://www.wendangku.net/doc/bb1389193.html,rge bulk power supply decoupling capacitors should be placed near the PAM8303D on the PVDD terminal.

Input resistors and capacitors need to be placed very close to input pins.

SD μ°C

Ordering Information

Configuration

PAM8303D of pins Type

Outline Dimensions

WCSP

Unit:Millimeter

0.2350.02

Millimeter REF Min Max A -- 1.10A10.050.15A20.780.94b 0.220.38c 0.080.23D 2.90 3.10E 2.90 3.10E1 4.75

5.05

e 0.65BSC L

0.40

0.70Outline Dimensions

MSOP8

Outline Dimensions

DFN3x3

Unit:Millimeter