MAXIM MAX9715 Technical data

General Description

The MAX9715 high-efficiency, stereo, Class D audio
power amplifier provides up to 2.8W per channel into a
4Ω speaker with a 5V supply. Maxim’s second-generation
Class D technology features robust output protection,
high efficiency, and high power-supply rejection (PSRR)
while eliminating the need for output filters. Selectable
gain settings, +10.5dB or +9.0dB, adjust the amplifier
gain to suit the audio input level and speaker load.

The MAX9715 features high PSRR (71dB at 1kHz),
allowing for operation from noisy supplies without addi­tional regulation. Comprehensive click-and-pop sup­pression eliminates audible clicks and pops at startup
and shutdown. The MAX9715 operates from a single 5V
supply and consumes only 12mA of supply current.
Integrated shutdown control reduces supply current to
less than 100nA.

The MAX9715 is fully specified over the extended

-40°C to +85°C temperature range and is available in a
thermally enhanced 16-pin TQFN-EP package.

Applications

High-End Notebook Audio

LCD Projectors

Portable Audio

Multimedia Docking Stations

Features

♦ 5V Single-Supply Operation

♦ Spread-Spectrum Modulator Reduces EMI

♦ 2.8W, Class D, Stereo Speaker Amplifier (4Ω)

♦ Filterless Class D Requires No LC Output Filter

♦ High PSRR (71dB at 1kHz)

♦ 86% Efficiency (R

L

= 8Ω, P

OUT

= 1W)

♦ Low-Power Shutdown Mode

♦ Integrated Click-and-Pop Suppression

♦ Low Total Harmonic Distortion: 0.06% at 1kHz

♦ Short-Circuit and Thermal Protection

♦ Internal Gain, +9.0dB or +10.5dB

♦ Available in Space-Saving Package

16-Pin Thin QFN-EP (5mm x 5mm x 0.8mm)

MAX9715

2.8W, Low-EMI, Stereo, Filterless
Class D Audio Amplifier

________________________________________________________________

Maxim Integrated Products

1

Pin Configurations

Ordering Information

Block Diagram

19-3589; Rev 2; 7/08

+

Denotes a lead-free/RoHS-compliant package.

*

EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX9715ETE+ -40°C to +85°C 16 TQFN-EP*

Typical Operating Circuit/Functional Diagram appears at
end of data sheet.

EVALUATION KIT

AVAILABLE

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.

4.5V TO 5.5V SUPPLY

INR

GAIN

INL

CLASS D

AMPLIFIER

MAX9715

OUTR+

OUTR-

OUTL+

OUTL-

TOP VIEW

BIAS

V

INR

INL

PGND

OUTR+

12 11 10 9

13

DD

14

15

16

+

MAX9715

1234

PGND

OUTL+

TQFN

OUTR-

OUTL-

DD

PV

8

SHDN

GND

7

GAIN

6

N.C.

5

DD

PV

MAX9715

2.8W, Low-EMI, Stereo, Filterless Class D
Audio Amplifier

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= PVDD= 5.0V, GND = PGND = 0V, V

SHDN

= VDD, C

BIAS

= 1μF, speaker impedance = 8Ω in series with 68μH connected between

OUT_+ and OUT_-, GAIN = +10.5dB, T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +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.

VDD, PVDD, to GND ...............................................................+6V

GND to PGND .......................................................-0.3V to +0.3V

Any Other Pin to PGND ............................. -0.3V to (V

DD

+ 0.3V)

Duration of OUT__ Short Circuit to PGND or PV

DD

....Continuous

Duration of OUT_+ Short Circuit between OUT_- ......Continuous

Continuous Current Into/Out of (PV

DD

, OUT__, PGND)........1.7A

Continuous Input Current (All Other Pins) ....................... ±20mA

Continuous Power Dissipation (T

A

= +70°C)

16-Pin TQFN-EP (derate 20.8mW/°C above +70°C)..1666mW

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

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

Junction Temperature......................................................+150°C

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GENERAL

Supply Voltage Range V

Quiescent Current I

Shutdown Supply Current I

Input Resistance R

Turn-On Time t

BIAS Voltage V

CLASS D SPEAKER AMPLIFIERS

Output Offset Voltage V

Maximum Speaker Amplifier Gain
(Note 3)

Power-Supply Rejection Ratio PSRR V

Output Power P

Total Harmonic Distortion Plus
Noise

Signal-to-Noise Ratio SNR

Maximum Capacitive Load C

Switching Frequency f

THD+N f = 1kHz

DD

DD

SHDN

IN

ON

BIAS

OS

A

V

OUT

L_MAX

SW

Inferred from PSRR test 4.5 5.5 V

No load 12.8 16 mA

V

SHDN

TA = +25°C 12.6 45

TA = T

GAIN = 0 10.5

GAIN = 1 9.0

IN_

THD+N = 1%

THD+N = 10%

P

OUT

P

OUT

Average frequency in spread-spectrum
operation

= 0V 0.1 2 μA

to T

MIN

MAX

PVDD or VDD = 4.5V to

= 0V

= 1W, BW = 22Hz to 22kHz 89

= 1W, A-weighted 93

5.5V

f = 1kHz, 100mV

f = 20kHz, 100mV

RL = 8Ω 1.4

= 4Ω 2.3

R

L

RL = 8Ω 1.7

= 4Ω 2.8

R

L

RL = 8Ω, P

= 4Ω, P

R

L

P-P

P-P

= 1.2W 0.06

OUT

= 2W 0.07

OUT

6.5 10 13.5 kΩ

25 ms

1.8 V

70

52.4 75

71

60

200 pF

1.00 1.22 1.40 MHz

mV

dB

dB

W

%

dB

MAX9715

2.8W, Low-EMI, Stereo, Filterless Class D
Audio Amplifier

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD= 5.0V, GND = PGND = 0V, V

SHDN

= VDD, C

BIAS

= 1μF, speaker impedance = 8Ω in series with 68μH connected between

OUT_+ and OUT_-, GAIN = +10.5dB, T

A

= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA= +25°C.) (Notes 1, 2)

Note 1: All devices are 100% production tested at TA= +25°C. All temperature limits are guaranteed by design.
Note 2: Speaker amplifier gain is defined as A

V

= (V

OUT_+

- V

OUT_-

) / VIN.

Note 3: Click-and-pop level testing performed with an 8Ω resistive load in series with 68μH inductive load connected across the

Class D BTL outputs. Mode transitions are controlled by the SHDN pin. Inputs AC-coupled to GND.

Note 4: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For R

L

= 4Ω, L = 33μH.

For R

L

= 8Ω, L = 68μH.

Typical Operating Characteristics

(VDD= 5.0V, C

VDD

= 3 x 0.1μF, C

BIAS

= 1μF, C

INL

= C

INR

= 1μF, AV= +10.5dB, TA= +25°C, unless otherwise noted.) (See the

Typical Operating Circuit/Functional Diagram

)

10 1k 100k10k100

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

MAX9715toc01

FREQUENCY (Hz)

THD+N (%)

1

0.1

0.001

0.01

P

OUT

= 0.35W

P

OUT

= 2W

VDD = 5V
R

L

= 4

Ω

10 1k 100k10k100

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

MAX9715toc02

FREQUENCY (Hz)

THD+N (%)

1

0.1

0.001

0.01

P

OUT

= 0.5W

P

OUT

= 1.25W

VDD = 5V
R

L

= 8

Ω

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Spread-Spectrum Modulation ±120 kHz

Crosstalk

Click-and-Pop Level K

Efficiency η

DIGITAL INPUTS (GAIN and SHDN)

Input High Voltage V

Input Low Voltage V

Input Leakage Current I

CP

IH

IL

LEAK

Channel-to-channel, f = 10kHz, P
left to right or right to left

Peak voltage,

= 1W,

OUT

72 dB

Into shutdown -64

A-weighted,
32 samples per
second (Note 4)

R

= 8Ω in series with 68μH, P

L

per channel, f = 1kHz

Out of shutdown -46

= 1W

OUT

86 %

2.0 V

SHDN ±1

GAIN ±1.5

0.8 V

dBV

μA

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

10

1

THD+N (%)

0.1

0.01

0.001

fIN = 1kHz AND 20Hz

01.00.5 2.0 3.0 4.03.5

1.5 2.5

OUTPUT POWER (W)

fIN = 10kHz

VDD = 5V
R

L

MAX9715toc03

= 4Ω

MAX9715

2.8W, Low-EMI, Stereo, Filterless Class D
Audio Amplifier

4 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VDD= 5.0V, C

VDD

= 3 x 0.1μF, C

BIAS

= 1μF, C

INL

= C

INR

= 1μF, AV= +10.5dB, TA= +25°C, unless otherwise noted.) (See the

Typical Operating Circuit/Functional Diagram

)

EFFICIENCY

vs. OUTPUT POWER

MAX9715toc05

OUTPUT POWER (W)

EFFICIENCY (%)

10

20

30

40

50

60

70

80

90

100

0

0

1

23

4

5

6

VDD = 5V
f

IN

= 1kHz

P

OUT

= P

OUTL

+ P

OUTR

OUTPUTS IN-PHASE

RL = 4

Ω

RL = 8

Ω

0

0.5

1.0

2.0

1.5

2.5

4.5 4.8 5.0 5.3 5.5

OUTPUT POWER

vs. SUPPLY VOLTAGE

MAX9715toc09

SUPPLY VOLTAGE (V)

OUTPUT POWER (W)

THD+N = 1%

fIN = 1kHz
R

L

= 8Ω

THD+N = 10%

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

fIN = 1kHz

10

fIN = 20Hz

1

THD+N (%)

0.1

0.01

0.001
0 0.5 1.0 1.5 2.52.0

OUTPUT POWER (W)

fIN = 10kHz

VDD = 5V

= 8

R

L

Ω

MAX9715toc04

EFFICIENCY

vs. SUPPLY VOLTAGE

100

90

80

70

60

50

40

EFFICIENCY (%)

30

fIN = 1kHz

20

10

= P

P

OUT

OUTPUTS IN-PHASE
THD+N = 1%

0

4.5 5.5

RL = 8

Ω

RL = 4

Ω

+ P

OUTL

OUTR

SUPPLY VOLTAGE (V)

OUTPUT POWER

vs. SUPPLY VOLTAGE

5.0

4.5

4.0

3.5

3.0

2.5

2.0

OUTPUT POWER (W)

1.5

1.0

0.5

0

4.5 4.8 5.0 5.3 5.5

THD+N = 10%

THD+N = 1%

SUPPLY VOLTAGE (V)

5.35.04.8

fIN = 1kHz
R

= 4Ω

L

MAX9715 toc06

MAX9715toc08

4.0

3.5

3.0

2.5

2.0

1.5

OUTPUT POWER (W)

1.0

THD+N = 1%

0.5

0

11k10010

OUTPUT POWER

vs. LOAD RESISTANCE

VDD = 5V
f

IN

L

LOAD

THD+N = 10%

LOAD RESISTANCE (Ω)

= 1kHz

= 33μH

MAX9715toc07