MAXIM MAX9730 User Manual

General Description

The MAX9730 features a mono Class G power amplifier
with an integrated inverting charge-pump power supply.
The charge pump can supply up to 500mA of peak out­put current over a 2.7VDC to 5.5VDC supply voltage
range, guaranteeing up to 2.4W output power into an
8Ω load. The 2.4W output power allows for transient
audio content to remain unclipped as the battery rail col­lapses over time.

The MAX9730 maximizes battery life by offering high­performance efficiency. Maxim’s proprietary output
stage provides efficiency levels greater than Class AB
devices without the EMI penalties commonly associat­ed with Class D amplifiers. High efficiency allows the
MAX9730 to be packaged in a WLP package without
derating the output power handling capability.

The device utilizes fully differential inputs and outputs,
comprehensive click-and-pop suppression, shutdown
control, and soft-start circuitry. The MAX9730 is fully
specified over the -40°C to +85°C extended tempera­ture range and is available in ultra-small, lead-free,
20-bump WLP (2mm x 2.5mm) and 28-pin TQFN (4mm
x 4mm) packages.

Features

o 2.7V to 5.5V Operation

o Integrated Charge-Pump Power Supply

o 63% Efficiency (V

CC

= 5V, P

OUT

= 1W)

o 2.4W Output Power into 8Ω at V

CC

= 5V

o Clickless/Popless Operation

o Small Thermally Efficient Packages

2mm x 2.5mm 20-Bump WLP
4mm x 4mm 28-Pin TQFN

MAX9730

2.4W, Single-Supply, Class G Power Amplifier

________________________________________________________________

Maxim Integrated Products

1

Ordering Information

MAX9730

+

IN+

FB+

R

IN+

CPV

DD

2.7V TO 5.5V

R

IN-

C

IN

C

IN

IN-

FB-

OUT+

OUT-

-

CLASS G

OUTPUT

STAGE

CHARGE

PUMP

R

FB+

R

FB-

V

CC

CPGNDGND

Simplified Block Diagram

19-0701; Rev 5; 3/10

For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.

EVALUATION KIT

AVAILABLE

MP3 Players
Personal Media Players
Handheld Gaming

Consoles

Cell Phones
Smartphones
Notebook Computers

Applications

Typical Application Circuit/Functional Diagram and Pin
Configurations appear at end of data sheet.

+

Denotes a lead(Pb)-free/RoHS-compliant package.
T = Tape and reel.
G45 indicates protective die coating.

*

EP = Exposed pad.

PART PIN-PACKAGE TEMP RANGE

MAX9730EWP+TG45 20 WLP -40°C to +85°C

MAX9730ETI+ 28 TQFN-EP* -40°C to +85°C

MAX9730

2.4W, Single-Supply, Class G Power Amplifier

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VCC= V

CPVDD

= V

SHDN

= 3.6V, V

GND

= V

CPGND

= 0V, R

IN+

= R

IN-

= 10kΩ, R

FB+

= R

FB-

= 10kΩ, RFS= 100kΩ, C1 = 4.7µF, C2 =

10µF; speaker load resistors (R

L

) are terminated between OUT+ and OUT-, unless otherwise stated; TA= T

MIN

to T

MAX

, unless other-

wise noted. Typical values are at T

A

= +25°C.) (Notes 1, 2)

Stresses beyond those listed under “Absolute Maximum 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 in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

(Voltages with respect to GND.)
V

CC

, CPVDD.............................................................-0.3V to +6V

PV

SS

, SVSS...............................................................-6V to +0.3V

CPGND..................................................................-0.3V to +0.3V

OUT+, OUT-...................................(SV

SS

- 0.3V) to (VCC+ 0.3V)

IN+, IN-, FB+, FB- ......................................-0.3V to (V

CC

+ 0.3V)

C1N..........................................(PV

SS

- 0.3V) to (CPGND + 0.3V)

C1P.......................................(CPGND - 0.3V) to (CPV

DD

+ 0.3V)

FS, SHDN ...................................................-0.3V to (V

CC

+ 0.3V)

Continuous Current Into/Out of

OUT+, OUT-, V

CC

, GND, SVSS.....................................800mA

CPV

DD

, CPGND, C1P, C1N, PVSS.................................800mA

Any Other Pin ..................................................................20mA

Continuous Power Dissipation (T

A

= +70°C)

20-Bump WLP (derate 10.3mW/°C above +70°C)........827mW

28-Pin TQFN (derate 20.8mW/°C above +70°C) ........1667mW

Operating Temperature Range ...........................-40°C to +85°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) ................................+300°C

Bump Temperature (soldering) Reflow............................+260°C

GENERAL

Supply Voltage Range V

Quiescent Current I

Chip Power Dissipation P

Shutdown Current I

Turn-On Time t

Input DC Bias Voltage V

Charge-Pump Oscillator
Frequency (Slow Mode)

Maximum Capacitive Load C

SHDN Input Threshold (Note 3)

SHDN Input Leakage Current ±1 µA

SPEAKER AMPLIFIER

Output Offset Voltage V

Common-Mode Rejection Ratio CMRR fIN = 1kHz (Note 4) 68 dB

Click-and-Pop Level V

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

CC

CC

DISS

SHDN

ON

BIAS

f

OSC

L

OS

Inferred from PSRR test 2.7 5.5 V

V

OUT

SHDN = GND 0.3 5 µA

Time from shutdown or power-on to full
operation

IN_ inputs 1.1 1.24 1.4 V

I

LOAD

I

LOAD

V

IH

V

IL

TA = +25°C ±3 ±15

T

MIN

= 2.8V

, f = 1kHz, RL = 8Ω 0.9 W

RMS

= 0mA (slow mode) 55 83 110

> 100mA (normal mode) 230 330 430

≤ TA ≤ T

MAX

Peak voltage into/out of shutdown

CP

A-weighted, 32 samples per second
(Notes 5, 6)

1.4

812mA

50 ms

200 pF

0.4

±20

-52 dBV

kHz

V

mV

MAX9730

2.4W, Single-Supply, Class G Power Amplifier

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VCC= V

CPVDD

= V

SHDN

= 3.6V, V

GND

= V

CPGND

= 0V, R

IN+

= R

IN-

= 10kΩ, R

FB+

= R

FB-

= 10kΩ, RFS= 100kΩ, C1 = 4.7µF, C2 =

10µF; speaker load resistors (R

L

) are terminated between OUT+ and OUT-, unless otherwise stated; TA= T

MIN

to T

MAX

, unless other-

wise noted. Typical values are at T

A

= +25°C.) (Notes 1, 2)

Note 1: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design.
Note 2: Testing performed with resistive and inductive loads to simulate an actual speaker load. For dynamic speakers,

R

L

= 8Ω, 68µH.

Note 3: Designed for 1.8V logic.
Note 4: R

IN_

and R

FB_

have 0.5% tolerance.

Note 5: Amplifier inputs AC-coupled to GND.
Note 6: Testing performed at room temperature with 8Ω resistive load in series with 68µH inductive load connected across BTL

output for speaker amplifier. Mode transitions are controlled by SHDN. V

CP

is the peak output transient expressed in dBV.

Note 7: Voltage gain is defined as: [V

OUT+

- V

OUT-

] / [V

IN+

- V

IN-

].

Note 8: Mode A tone burst tested at full amplitude for one cycle and half amplitude for nine cycles. Mode B tone burst tested at

full amplitude for three cycles and half amplitude for seven cycles. Full amplitude is defined as 1% THD+N at full battery
(V

CC

= 4.2V).

Electrical Characteristics

table targets must be met at THD+N = 1% for one cycle (Mode A) and THD+N <

5% for three cycles (Mode B).

Note 9: Dynamic range is calculated by measuring the RMS voltage difference between a -60dBFS output signal and the noise

floor, then adding 60dB. Full scale is defined as the output signal needed to achieve 1% THD+N.

Voltage Gain A

Continuous Output Power P

Output Voltage V

Power-Supply Rejection Ratio
(Note 4)

Total Harmonic Distortion Plus
Noise

Signal-to-Noise Ratio SNR

Dynamic Range DR (Note 9)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

(Notes 4, 7) 11.5 12 12.5 dB

V

OUT

THD+N = 1%, f = 1kHz,

= 8Ω

R

L

f = 1kHz, 1% THD+N,

= 1µF + 10Ω

Z

L

OUT

f = 10kHz, 1% THD+N,
Z

= 1µF + 10Ω

L

VCC = 2.7V to 5.5V 63 77

f = 217Hz, 200mV

PSRR

f = 1kHz, 200mV

P-P

f = 20kHz, 200mV

THD+N

RL = 8Ω, V

= 8Ω, V

R

L

V

= 0.5V

OUT

= 1kHz / 400mV

OUT

= 1kHz / 1V

OUT

, inputs to GND by C1N,

RMS

A-weighted

VCC = 5V 2.4

VCC = 4.2V 1.67

VCC = 3.6V 1.25

V

= 3.0V 0.8

CC

VCC = 5V 7.1

VCC = 4.2V 5.9

VCC = 3.6V 5.1

V

= 3.0V 4.2

CC

VCC = 5V 6.5

VCC = 4.2V 5.4

VCC = 3.6V 4.7

VCC = 3.0V 3.8

ripple 77

P-P

ripple 77

ripple 58

P-P

RMS

RMS

22Hz to 22kHz 96

A-weighted 99

0.007

0.12

95 dB

V

W

RMS

dB

%

dB

MAX9730

2.4W, Single-Supply, Class G Power Amplifier

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VCC= V

CPVDD

= V

SHDN

= 3.6V, V

GND

= V

CPGND

= 0V, R

IN+

= R

IN-

= 10kΩ, R

FB+

= R

FB-

= 10kΩ, RFS= 100kΩ, C1 = 4.7µF, C2 =

10µF, R

L

= 8Ω; speaker load resistors (RL) are terminated between OUT+ and OUT-, unless otherwise stated; TA= T

MIN

to T

MAX

,

unless otherwise noted. Typical values are at T

A

= +25°C.) (Notes 1, 2)

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9730 toc01

FREQUENCY (kHz)

THD+N (%)

1010.1

0.01

0.1

1

10

0.001

0.01 100

V

CC

= 3V

P

OUT

= 0.69W

P

OUT

= 0.33W

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9730 toc02

FREQUENCY (kHz)

THD+N (%)

1010.1

0.01

0.1

1

10

0.001

0.01 100

V

CC

= 3.6V

P

OUT

= 0.37W

P

OUT

= 0.93W

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9730 toc03

FREQUENCY (kHz)

THD+N (%)

1010.1

0.01

0.1

1

10

0.001

0.01 100

V

CC

= 5V

P

OUT

= 0.83W

P

OUT

= 2.08W

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9730 toc04

OUTPUT POWER (W)

THD+N (%)

1.00.5

0.01

0.1

1

10

0.001

01.5

V

CC

= 3V

f

IN

= 1kHz

f

IN

= 10kHz

f

IN

= 20Hz

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9730 toc05

OUTPUT POWER (W)

THD+N (%)

1.51.00.5

0.01

0.1

1

10

0.001

02.0

V

CC

= 3.6V

f

IN

= 1kHz

f

IN

= 10kHz

f

IN

= 20Hz

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9730 toc06

OUTPUT POWER (W)

THD+N (%)

3.02.52.01.51.00.5

0.01

0.1

1

10

0.001
0 3.5

f

IN

= 20Hz

f

IN

= 10kHz

f

IN

= 1kHz

V

CC

= 5V

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX9730 toc07

FREQUENCY (kHz)

PSRR (dB)

1010.1

-80

-70

-60

-50

-40

-30

-20

-10

0

-90

0.01 100

V

RIPPLE

= 200mV

P-P

POWER EFFICIENCY
vs. OUTPUT POWER

MAX9730 toc08

OUTPUT POWER (W)

EFFICIENCY (%)

0.8 1.00.60.40.2

10

20

30

40

50

60

70

0

01.2

V

CC

= 3V

f

IN

= 1kHz

POWER EFFICIENCY
vs. OUTPUT POWER

MAX9730 toc09

OUTPUT POWER (W)

EFFICIENCY (%)

1.00.5

10

20

30

40

50

60

70

0

0 1.5

V

CC

= 3.6V

f

IN

= 1kHz