Diodes PAM8902 User Manual

A

f

30-VPP MONO CLASS-D AUDIO AMPLIFIER FOR PIEZO/CERAMIC SPEAKERS

Description

The PAM8902 is a mono, Class-D audio amplifier with integrated

boost converter designed for piezo and ceramic speakers.The

PAM8902 is capable of driving a ceramic/piezo speaker with

(10.6Vrms) from a 3.6V power supply.The PAM8902's Boost

30V

PP

converter operates at a fixed frequency of 1.5MHz, and provides a

17.5V supply with a minimum number of external components.

PAM8902 features an integrated audio low pass filter that rejects high

frequency noise thus improving audio fidelity. And three gain modes

of 18dB, 22dB and 26dB for ease of use. PAM8902 also provides

thermal, short, under- and over-voltage protection.

The PAM8902 is available in a 16-ball 1.95mm x 1.95mm CSP

package and 16-pin QFN4x4 package.

Features

Pin Assignments

Product Line o

Diodes Incorporated

PAM8902

 Supply Voltage Range From 2.5V to 5.5V

 30 V

 Integrated Boost Converter Generates 17.5V Supply

 Programmable Soft-Start

 Small Boost Converter Inductor

 Selectable Gain of 18dB, 22dB, and 26dB

 Selectable Boost Output Voltage of 8V, 12V and 17.5V

 Low Shutdown Current: < 1µA

 Built-in Thermal, OCP, OVP, Short Protection

 Available in Space Saving Packages:

Output Load Voltage From a 2.5V Supply

PP

 16-ball 1.95mmx1.95mm CSP Package

 16-pin QFN4x4 Package

Applications

 Wireless or Cellular Handsets

 Portable DVD Player

 Personal Digital Assistants (PDAs )

 Electronic Dictionaries

 Digital Still Cameras

PAM8902

Document number: DSxxxxx Rev. 1 - 4

1 of 13

www.diodes.com

November 2012

A

f

Typical Applications Circuit

Product Line o

Diodes Incorporated

PAM8902

Pin Descriptions

Name

Bump (CSP)

PVCC A1 16 VOUT A2 1

SW A3 2

PGND1 A4 4

OUT+ B1 15 VSET B2 3

COMP B3 5

AVDD B4 6

OUT- C1 14

GSET C2 11

VCM C3 7

AGND C4 8

PGND2 D1 13

ENA D2 12

INN D3 10 INP D4 9

Pin Number

QFN4x4

Function

Audio Amplifier Power Supply

Boost Converter Output

Boost Converter Switching Node

Boost Converter Power Ground

Positive Differential Audio Output

Boost Converter Output Voltage Setting(8V,12V,17.5V)

Boost Converter Compensation

Power Supply

Negative Differential Audio Output

Amplifier Gain Setting ( 18dB , 22dB , 26dB)

Common Mode Bypass Cap

Analog Ground

ClassD Power Ground

Whole Chip Enable

Negative Differential Audio Input

Positive Differential Audio Input

PAM8902

Document number: DSxxxxx Rev. 1 - 4

2 of 13

www.diodes.com

November 2012

A

f

Functional Block Diagram

Product Line o

Diodes Incorporated

PAM8902

Absolute Maximum Ratings (@T

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

Input Voltage

Maximum Junction Temperature +150

Storage Temperature -65 to +150

Soldering Temperature 350, 10sec

Recommended Operating Conditions (@T

Parameter Rating Unit

Supply Voltage Range 2.5 to 5.5 V

Ambient Temperature Range -40 to +85 °C

Junction Temperature Range -40 to +125 °C

PAM8902

Document number: DSxxxxx Rev. 1 - 4

= +25°C, unless otherwise specified.)

A

-0.3 to V

+0.3

DD

www.diodes.com

= +25°C, unless otherwise specified.)

A

3 of 13

V

°C

November 2012

A

f

Product Line o

Diodes Incorporated

PAM8902

Thermal Information

Parameter Package Symbol Max Unit

Thermal Resistance (Junction to Ambient)

Thermal Resistance (Junction to Case)

CSP

QFN4x4-16 52

CSP

QFN4x4-16 30

θ

JA

θ

JC

Electrical Characteristics (@T

= +25°C, VDD = 3.6V, CL = 1µF, V

A

Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage

Quiescent Current

Shutdown Current

Wake-Up Time

Chip Enable

Chip Disable

GSET/ VSET High

GSET/ VSET Floating

GSET/ VSET Low

V

DD

I

Q

I

SD

T

WU

V

EH

V

EL

V

EN > 1.2V, V

EN = 0V 0.1 1 µA

EN from Low to High 40 mS

1.2

0.4

H

1

F

0 0.5

L

= High

SET

= Floating

SET

= GND

SET

Under Voltage Lockout Threshold UVLO VDD from High to Low 2.2

Under Voltage Lockout Hysteresis UVLO(H) VDD from Low to High 0.2

Thermal Shutdown Threshold OTP 150 °C

Thermal Shutdown Lockout Hysyeresis OTP(H) 30 °C

Boost Converter

V

Output Voltage

Current Limit

Lowside MOSFET R

DS(ON)

Boost Switching Frequency

1 V

O

VO2 V

VO3 V

C

L

RLS IO = 50mA

f

OSCB

= GND, No Load

SET

= NC, No Load

SET

= AVDD, No Load

SET

Average Input Current 0.8 A

1.1 1.5 1.9 MHz

Class D

Class D Amplifier Switching Frequency

f

OSCD

Common Mode Reject Ratio CMRR

Output Offset Voltage

R

DS(ON)

Closed-Loop Voltage Gain

V

OS

RP

A

V

AV2 G

AV3 G

Power Supply Reject Ratio PSRR

Total Harmonic Distortion Plus Noise THD+N

Input AC-GND 225 375 475 KHz

V

= + -100mV, VDD = 3.6V

IN

Output Offset Voltage 5 50 mV

High Side 1.5 Ω Low Side 0.6 Ω

1 G

= AVDD, VO = 1V

SET

= NC, VO = 1V

SET

= GND, VO = 1V

SET

200m V

V

O

Supply Ripple @ 217Hz

PP

= 5VRMS

RMS

Signal to Noise Ratio SNR Input AC Ground, A–Weighting 90 dB

PAM8902

Document number: DSxxxxx Rev. 1 - 4

4 of 13

www.diodes.com

90

75

Float, unless otherwise specified.)

SET

°C/W

2.5 5.5 V

30 48

10 18

5 12

VDD -0.5

7.2 8 8.8 V

10.8 12 13.2 V

16 17.5 19 V

0.5 Ω

60 dB

RMS

25 26 27

21 22 23

17 18 19 dB

70 dB

0.3 %

mA

V

VDD

VDD -1

V

November 2012