Rainbow Electronics MAX9704 User Manual

General Description

The MAX9703/MAX9704 mono/stereo class D audio power amplifiers provide class AB amplifier performance with class D efficiency, conserving board space and eliminating the need for a bulky heatsink. Using a class D architecture, these devices deliver up to 15W while offering up to 78% efficiency. Proprietary and patent-protected modulation and switching schemes render the traditional class D output filter unnecessary.

The MAX9703/MAX9704 offer two modulation schemes: a fixed-frequency mode (FFM), and a spread-spectrum mode (SSM) that reduces EMI-radiated emissions due to the modulation frequency. The device utilizes a fully differential architecture, a full bridged output, and comprehensive click-and-pop suppression.

The MAX9703/MAX9704 feature high 80dB PSRR, low

0.07% THD+N, and SNR in excess of 100dB. Short-circuit and thermal-overload protection prevent the devices from being damaged during a fault condition. The MAX9703 is available in a 32-pin TQFN (5mm x 5mm x 0.8mm) package. The MAX9704 is available in a 32-pin TQFN (7mm x 7mm x 0.8mm) package. Both devices are specified over the extended -40°C to +85°C temperature range.

Applications

Features

♦ Filterless Class D Amplifier ♦ Unique Spread-Spectrum Mode Offers 5dB

Emissions Improvement Over Conventional Methods

♦ Up to 78% Efficient ♦ 15W Output Power into 8Ω ♦ Up to 20W Peak Power ♦ Low 0.07% THD+N ♦ High PSRR (80dB at 1kHz) ♦ 10V to 25V Single-Supply Operation ♦ Differential Inputs Minimize Common-Mode Noise ♦ Pin-Selectable Gain Reduces Component Count ♦ Industry-Leading Click-and-Pop Suppression ♦ Low Quiescent Current (24mA) ♦ Low-Power Shutdown Mode (0.2µA) ♦ Short-Circuit and Thermal-Overload Protection ♦ Available in Thermally Efficient, Space-Saving

Packages

32-Pin TQFN (5mm x 5mm x 0.8mm)–MAX9703 32-Pin TQFN (7mm x 7mm x 0.8mm)–MAX9704

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum

Mono/Stereo Class D Amplifiers

________________________________________________________________ Maxim Integrated Products 1

19-3160; Rev 1; 3/04

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

Ordering Information

PART

AMP

MAX9703ETJ

32 TQFN-EP*

Mono

MAX9704ETJ

32 TQFN-EP*

Stereo

*EP = Exposed paddle.

LCD TVs LCD Monitors Desktop PCs LCD Projectors

Hands-Free Car Phone Adaptors

Automotive

Pin Configurations appear at end of data sheet.

MAX9704

0.47µF INL+ OUTL+

OUTL-INL-

0.47µF

H-BRIDGE

0.47µF INR+ OUTR+

OUTR-INR-

0.47µF

H-BRIDGE

MAX9703

0.47µF IN+ OUT+

OUT-

IN-

0.47µF

H-BRIDGE

Block Diagrams

TEMP RANGE

-40oC to +85oC

PIN-PACKAGE

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum Mono/Stereo Class D Amplifiers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

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.

(All voltages referenced to GND.) V

DD

to PGND, AGND .............................................................30V

OUTR_, OUTL_, C1N..................................-0.3V to (V

DD

+ 0.3V)

C1P............................................(V

DD

- 0.3V) to (CHOLD + 0.3V)

CHOLD........................................................(V

DD

- 0.3V) to +40V

All Other Pins to GND.............................................-0.3V to +12V

Duration of OUTR_/OUTL_

Short Circuit to GND, V

DD

..................................................10s

Continuous Input Current (V

DD

, PGND) ...............................1.6A

Continuous Input Current......................................................0.8A

Continuous Input Current (all other pins)..........................±20mA

Continuous Power Dissipation (T

A

= +70°C) MAX9703 32-Pin TQFN (derate 21.3mW/°C

above +70°C)..........................................................1702.1mW

MAX9704 32-Pin TQFN (derate 33.3mW/°C

above +70°C)..........................................................2666.7mW

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

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

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

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

ELECTRICAL CHARACTERISTICS

(VDD= 15V, GND = PGND = 0V, SHDN ≥ VIH, AV= 16dB, CSS= CIN= C

REG

= 0.47µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 = GND

(f

S

= 660kHz), RLconnected between OUTL+ and OUTL- and OUTR+ and OUTR-, TA= T

MIN

to T

MAX

, unless otherwise noted.

Typical values are at T

A

= +25°C.) (Notes 1, 2)

PARAMETER

CONDITIONS

UNITS

GENERAL

Supply Voltage Range V

DD

Inferred from PSRR test 10 25 V

MAX9703 14 22

Quiescent Current I

DD

RL = OPEN

MAX9704 24 34

mA

Shutdown Current

0.2 1.5 µA

CSS = 470nF 100

Turn-On Time t

ON

CSS = 180nF 50

ms

Amplifier Output Resistance in Shutdown

SHDN = GND 150 330

kΩ

AV = 13dB 35 58 80 AV = 16dB 30 48 65 AV = 19.1dB 23 39 55

Input Impedance R

IN

AV = 29.6dB 10 15 22

kΩ

G1 = L, G2 = L G1 = L, G2 = H G1 = H, G2 = L

13

Voltage Gain A

V

G1 = H, G2 = H

16

dB

Gain Matching Between channels (MAX9704) 0.5 % Output Offset Voltage V

OS

±6 ±30

mV

fIN = 1kHz, input referred 60

dB

VDD = 10V to 25V 54 80

f

RIPPLE

= 1kHz 80

Power-Supply Rejection Ratio (Note 3)

PSRR

200mV

P-P

ripple

f

RIPPLE

= 20kHz 66

dB

RL = 4Ω 7.5

Output Power P

OUT

TH D + N = 10%, f = 1kH z, T

A

= + 25° C

R

L

= 8Ω, VDD = 20V 20

W

SYMBOL

MIN TYP MAX

I

SHDN

Common-Mode Rejection Ratio CMRR

29.4 29.6 29.8

18.9 19.1 19.3

12.8

15.9

13.2

16.3

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum

Mono/Stereo Class D Amplifiers

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= 15V, GND = PGND = 0V, SHDN ≥ VIH, AV= 16dB, CSS= CIN= C

REG

= 0.47µF, C1 = 100nF, C2 = 1µF, FS1 = FS2 = GND

(f

S

= 660kHz), RLconnected between OUTL+ and OUTL- and OUTR+ and OUTR-, TA= T

MIN

to T

MAX

, unless otherwise noted.

Typical values are at T

A

= +25°C.) (Notes 1, 2)

PARAMETER

CONDITIONS

Total Harmonic Distortion Plus Noise

fIN = 1kHz, either FFM or SSM, RL = 8Ω, P

OUT

= 4W

%

FFM 94

BW = 22Hz to 22kHz

SSM 88 FFM 97

Signal-to-Noise Ratio SNR

R

L

= 8Ω, P

OUT

=

10W, f = 1kHz

A-weighted

SSM 91

Crosstalk Left to right, right to left, 8Ω load, fIN = 10kHz 65

FS1 = L, FS2 = L 560 670 800 FS1 = L, FS2 = H 940 FS1 = H, FS2 = L 470

Oscillator Frequency f

OSC

FS1 = H, FS2 = H (spread-spectrum mode)

670

Efficiency η P

OUT

= 15W, f = 1kHz, RL = 8Ω 78 %

Regulator Output V

REG

6V

DIGITAL INPUTS (SHDN, FS_, G_) (Note 4)

V

IH

2.5

Input Thresholds

V

IL

0.8

V

Input Leakage Current ±1µA

Note 1: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design. Note 2: Testing performed with a resistive load in series with an inductor to simulate an actual speaker load. For R

L

= 8Ω, L = 68µH.

For R

L

= 4Ω, L = 33µH.

Note 3: PSRR is specified with the amplifier inputs connected to GND through C

IN

.

Note 4: Do not apply more than 8V to any logic pin.

SYMBOL

THD+N

MIN TYP MAX UNITS

0.07

±7%

dB

kHz

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum Mono/Stereo Class D Amplifiers

4 _______________________________________________________________________________________

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9703/04 toc01

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.1

1

10

0.01 10 100k

VDD = 15V R

L

= 4

Ω

A

V

= 16dB

P

OUT

= 4W

P

OUT

= 500mW

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9703/04 toc02

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.1

1

10

0.01 10 100k

VDD = 15V R

L

= 8

Ω

A

V

= 16dB

P

OUT

= 500mW

P

OUT

= 8W

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9703/04 toc03

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.1

1

10

0.01 10 100k

VDD = 20V R

L

= 8

Ω

A

V

= 16dB

P

OUT

= 8W

P

OUT

= 500mW

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

MAX9703/04 toc04

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.1

1

10

0.01 10 100k

VDD = 20V R

L

= 8

Ω

A

V

= 16dB

P

OUT

= 8W

SSM

FFM

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9703/04 toc07

OUTPUT POWER (W)

THD+N (%)

42681012 14 16 18

0.1

1

10

100

0.01 020

VDD = 20V R

L

= 8

Ω

A

V

= 16dB

f = 100Hz

f = 1kHz

f = 10kHz

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9703/04 toc05

OUTPUT POWER (W)

THD+N (%)

6

45

231

0.1

1

10

100

0.01 010978

VDD = 15V R

L

= 4

Ω

A

V

= 16dB

f = 10kHz

f = 1kHz

f = 100Hz

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9703/04 toc06

OUTPUT POWER (W)

THD+N (%)

12345678910 11 12 13 14

0.1

1

10

0.01 015

VDD = 15V R

L

= 8

Ω

A

V

= 16dB

f = 100Hz

f = 1kHz

f = 10kHz

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

MAX9703/04 toc08

OUTPUT POWER (W)

THD+N (%)

1234

5678

91011 12 13 141516 17 18 19

0.1

1

10

0.01 020

FFM (335kHz)

SSM

VDD = 20V R

L

= 8

Ω

A

V

= 16dB

f = 1kHz

EFFICIENCY vs. OUTPUT POWER

MAX9703/04 toc09

OUTPUT POWER (W)

EFFICIENCY (%)

86423 5 7

9

1

10

20

30

40

50

60

70

80

90

100

0

010

VDD = 12V A

V

= 16dB

f = 1kHz

RL = 4

Ω

RL = 8

Ω

Typical Operating Characteristics

(33µH with 4Ω, 68µH with 8Ω, part in SSM mode, 136µH with 16Ω, measurement BW = 22Hz to 22kHz, unless otherwise noted.)

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum

Mono/Stereo Class D Amplifiers

_______________________________________________________________________________________ 5

EFFICIENCY vs. OUTPUT POWER

MAX9703/04 toc10

OUTPUT POWER (W)

EFFICIENCY (%)

16

12

8

4

2

6

10

14 18

10

20

30

40

50

60

70

80

90

100

0

020

VDD = 15V A

V

= 16dB

f = 1kHz

RL = 16

Ω

RL = 8

Ω

OUTPUT POWER

vs. SUPPLY VOLTAGE

MAX9703/04 toc11

SUPPLY VOLTAGE (V)

OUTPUT POWER (W)

0

6 4 2

8

10

12

14

16

18

20

10 1613 19 22 25

RL = 8

Ω

RL = 16

Ω

AV = 16dB THD+N = 10%

20 18

16 14 12 10

8 6 4 2 0

110100

OUTPUT POWER

vs. LOAD RESISTANCE

MAX9703/04 toc12

LOAD RESISTANCE (Ω)

OUTPUT POWER (W)

THD+N = 1%

THD+N = 10%

VDD = 15V R

L

= 8

Ω

A

V

= 16dB

24 22 20 18 16 14 12 10

8 6 4 2 0

110100

OUTPUT POWER

vs. LOAD RESISTANCE

MAX9703/04 toc13

LOAD RESISTANCE (Ω)

OUTPUT POWER (W)

VDD = 20V R

L

= 8

Ω

A

V

= 16dB

THD+N = 10%

THD+N = 1%

CROSSTALK vs. FREQUENCY

MAX9703/04 toc16

FREQUENCY (Hz)

CROSSTALK (dB)

10k1k100

-80

-100

-60

-40

-20

0

-120 10 100k

LEFT TO RIGHT

RIGHT TO LEFT

AV = 16dB 1% THD+N V

DD

= 15V

8Ω LOAD

COMMON-MODE REJECTION RATIO

vs. FREQUENCY

MAX9703/04 toc14

FREQUENCY (Hz)

CMRR (dB)

10k1k100

-70

-60

-50

-40

-30

-20

-10

0

-80 10 100k

VDD = 15V R

L

= 8

Ω

A

V

= 16dB

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

MAX9703/04 toc15

FREQUENCY (Hz)

PSRR (dB)

10k1k100

-100

-80

-60

-40

-20

0

-120 10 100k

AV = 16dB R

L

= 8

Ω

200mV

P-P

INPUT

V

DD

= 15V

OUTPUT FREQUENCY SPECTRUM

MAX9703/04 toc17

FREQUENCY (kHz)

OUTPUT MAGNITUDE (dB)

-120

-100

-80

-60

-40

-20

0

20

-140 181612 144 6 8 102020

FFM MODE A

V

= 16dB UNWEIGHTED f

IN

= 1kHz

P

OUT

= 5W

R

L

= 8

Ω

OUTPUT FREQUENCY SPECTRUM

MAX9703/04 toc18

FREQUENCY (kHz)

OUTPUT MAGNITUDE (dB)

-120

-100

-80

-60

-40

-20

0

20

-140 181612 144 6 8 102020

SSM MODE A

V

= 16dB UNWEIGHTED f

IN

= 1kHz P

OUT

= 5W

R

L

= 8

Ω  

Typical Operating Characteristics (continued)

(33µH with 4Ω, 68µH with 8Ω, part in SSM mode, 136µH with 16Ω, measurement BW = 22Hz to 22kHz, unless otherwise noted.)

MAX9703/MAX9704

15W, Filterless, Spread-Spectrum Mono/Stereo Class D Amplifiers

6 _______________________________________________________________________________________

OUTPUT FREQUENCY SPECTRUM

MAX9703/04 toc19

FREQUENCY (kHz)

OUTPUT MAGNITUDE (dB)

-120

-100

-80

-60

-40

-20

0

20

-140 181612 144 6 8 102020

SSM MODE A

V

= 16dB A-WEIGHTED f

IN

= 1kHz P

OUT

= 5W

R

L

= 8

Ω



100k 1M 10M 100M

WIDEBAND OUTPUT SPECTRUM

(FFM MODE)

MAX9703/04 toc20

FREQUENCY (Hz)

OUTPUT AMPLITUDE (dBV)

0

-120

-100

-80

-60

-40

-20

RBW = 10kHz V

DD

= 15V

100k 1M 10M 100M

WIDEBAND OUTPUT SPECTRUM

(SSM MODE)

MAX9703/04 toc21

FREQUENCY (Hz)

OUTPUT AMPLITUDE (dBV)

0

-120

-100

-80

-60

-40

-20

RBW = 10kHz V

DD

= 15V

TURN-ON/TURN-OFF RESPONSE

MAX9703/04 toc22

20ms/div

OUTPUT

1V/div

5V/div

SHDN

f = 1kHz R

L

= 8

Ω

CSS = 180pF

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9703/04 toc23

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

22191613

10

5

15

20

25

30

35

0

10 25

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX97703/04 toc24

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (µA)

18161412

0.10

0.05

0.15

0.20

0.25

0.30

0.35

0

10 20

Typical Operating Characteristics (continued)

(33µH with 4Ω, 68µH with 8Ω, part in SSM mode, 136µH with 16Ω, measurement BW = 22Hz to 22kHz, unless otherwise noted.)