MAXIM MAX9742 Technical data

General Description

The MAX9742 stereo Class D audio power amplifier
delivers up to 2 x 16W into 4Ω loads. The MAX9742
features high-power efficiency (92% with 8Ω loads),
eliminating the need for a bulky heatsink and conserv­ing power. The MAX9742 operates from a 20V to 40V
single supply or a ±10V to ±20V dual supply. Features
include fully differential inputs, comprehensive click­and-pop suppression, low-power shutdown mode, and
an externally adjustable gain. Short-circuit and thermal­overload protection prevent the device from being
damaged during a fault condition.

The MAX9742 is available in a thermally efficient 36-pin
TQFN (6mm x 6mm x 0.8mm) package and is specified
over the -40°C to +85°C extended temperature range.

Applications

CRT TVs

Flat-Panel Display TVs

Audio Docking Stations

Multimedia Monitors

Features

 2 x 16W Output Power (RL= 4Ω, THD+N = 10%)
 High Efficiency: Up to 92% with RL= 8Ω
 Mute and Shutdown Modes
 Differential Inputs Suppress Common-Mode Noise
 Adjustable Gain
 Integrated Click-and-Pop Suppression
 Low 0.06% THD+N at 3.5W, RL= 8Ω
 Output Short-Circuit and Thermal Protection
 Available in Space-Saving, 6mm x 6mm, 36-Pin

TQFN Package

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

________________________________________________________________

Maxim Integrated Products

1

Simplified Block Diagrams

19-0731; Rev 0; 1/07

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.

EVALUATION KIT

AVAILABLE

Pin Configuration located at end of data sheet.

Ordering Information

+

Denotes lead-free package.

*

EP = Exposed paddle.

Simplified Block Diagrams continued at end of data sheet.

SINGLE-SUPPLY CONFIGURATION

C

FBL

PART TEMP RANGE PIN-PACKAGE

MAX9742ETX+ -40°C to +85°C 36 TQFN-EP* T3666-3

PKG

CODE

R

F1

20V TO 40V

FBL

V

DD

MAX9742

CLASS D

MODULATOR AND

HALF-BRIDGE

CLASS D

MODULATOR AND

HALF-BRIDGE

CONTROL LOGIC/

POWER-UP

SEQUENCING

FBR SFT

V

SHDN

SS

ON

OFF

R

F1

C

L

OUTL

OUTR

C

SFT

F

L

F

OUT

R

C

C

ZBL

F

C

ZBL

C

OUT

R

ZBL

F

C

ZBL

LEFT NEGATIVE

AUDIO INPUT

LEFT POSITIVE

AUDIO INPUT

RIGHT POSITIVE

AUDIO INPUT

RIGHT NEGATIVE

AUDIO INPUT

C

IN

R

IN1

C

IN

R

IN2

C

R

F2

V

DD

2

R

C

F2

C

IN

R

IN2

C

IN

R

IN1

INL-

INL+

FBL

MID

FBR

INR+

INR-

C

FBR

MAX9742

Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS—Single-Supply, Single-Ended Output

(VDD= 24V, VSS= V

SUB

= LGND = 0V, V

SHDN

= 3.3V, V

MID

= 12V, C

VDD

= 660µF, C

MID1

= 10µF, C

MID2

= 10µF, R1 = R2 = R3 =

10kΩ, C

SFT

= 0.47µF, C

OUT

= 1000µF, C

FB_1

= 150pF, C

FB_2

= 10pF, C

BOOT

= 0.1µF, C

REGP

= C

REGM

= 1µF, R

IN_

= 30.1kΩ,

R

F1A

= 121kΩ, R

F1B

= 562kΩ, RF2= 681kΩ, R

REF

= 68kΩ, RL= ∞, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 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.

VDDto VSS, NSENSE ..............................................-0.3V to +45V

MID, LGND, LV

DD

, REGM, REGP, OUTR,

OUTL to V

SS

.......................................................-0.3V to +45V

MID, LGND, LV

DD

, REGM, REGP, OUTR,

OUTL to V

DD

.......................................................-45V to +0.3V

REGLS to V

SS

.........................................................-0.3V to +12V

MID to REGP, REGM...............(V

REGM

- 0.3V) to (V

REGP

+ 0.3V)

REGP to REGM.......................................................-0.3V to +12V

LV

DD

to LGND..........................................................-0.3V to +6V

SHDN to LGND.........................................................-0.3V to +4V

SFT to LGND ............................................................-0.3V to +6V

FB_, IN_+, IN_-, REFCUR to REGP,

REGM..................................(V

REGM

- 0.3V) to (V

REGP

+ 0.3V)

BOOTR to OUTR ....................................................-0.3V to +12V

BOOTL to OUTL .....................................................-0.3V to +12V

OUTR, OUTL Shorted to LGND..................................Continuous

Continuous Power Dissipation (T

A

= +70°C) (Note 1)
Single-Layer Board:

36-Pin TQFN (derate 26.3mW/°C above +70°C) ...........2.11W

Multilayer Board:

36-Pin TQFN (derate 35.7mW/°C above +70°C) ...........2.86W

Junction-to-Ambient Thermal Resistance (θ

JA

)
Single-Layer Board:

36-Pin TQFN.................................................................38°C/W

Multilayer Board:

36-Pin TQFN.................................................................28°C/W

Junction-to-Case Thermal Resistance (θ

JC

) ...................1.4°C/W

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

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

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

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

Note 1: Actual power capabilities are dependent on PCB layout. See the

Thermal Considerations

section.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V

Supply Current I

Mute Mode Supply Current No load, V

Shutdown Current No load, V

Switching Frequency f

Power-Supply Rejection Ratio
(Note 4)

Crosstalk
(Notes 5 and 6)

Continuous Output Power
(Notes 5, 6, and 7)

Efficiency
(Notes 5, 6, and 7)

DD

DD

SW

PSRR V

P

OUT

(Note 3) 20 40 V

No load, output filter removed 15 mA

= 0V (outputs not switching) 8 mA

SFT

= 0V 0.8 1.3 mA

SHDN

= 24V + 500mV

DD

L to R, R to L, R

, f = 1kHz 68 dB

P-P

= 8Ω, P

L

= 1W, f = 1kHz -78 dB

OUT

RL = 8Ω, fIN = 1kHz, THD+N = 10% 9.5

RL = 8Ω, fIN = 1kHz, THD+N = 10%,

= 35V

V

DD

RL = 4Ω, fIN = 1kHz, THD+N = 10% 16

R

= 8Ω, P

L

= 9.5W, THD+N = 10% 92 %

OUT

300 kHz

20.5

W

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

_______________________________________________________________________________________ 3

)

ELECTRICAL CHARACTERISTICS—Single-Supply, Single-Ended Output (continued)

(VDD= 24V, VSS= V

SUB

= LGND = 0V, V

SHDN

= 3.3V, V

MID

= 12V, C

VDD

= 660µF, C

MID1

= 10µF, C

MID2

= 10µF, R1 = R2 = R3 =

10kΩ, C

SFT

= 0.47µF, C

OUT

= 1000µF, C

FB_1

= 150pF, C

FB_2

= 10pF, C

BOOT

= 0.1µF, C

REGP

= C

REGM

= 1µF, R

IN_

= 30.1kΩ,

R

F1A

= 121kΩ, R

F1B

= 562kΩ, RF2= 681kΩ, R

REF

= 68kΩ, RL= ∞, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 2)

ELECTRICAL CHARACTERISTICS—Dual Supplies

(VDD= 15V, VSS= V

SUB

= -15V, V

SHDN

= 3.3V, V

MID

= LGND = 0V, C

VDD

= C

VSS

= 1000µF, C

BYP

= 1µF, C

SFT

= 0.22µF, C

FB_1

=

150pF, C

FB_2

= 10pF, C

BOOT

= 0.1µF, C

REGP

= C

REGM

= 1µF, R

IN_

= 30.1kΩ, R

F1A

= 121kΩ, R

F1B

= 562kΩ, RF2= 681kΩ, R

REF

=

68kΩ, R

L

= ∞, TA= T

MIN

to T

MAX

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Total Harmonic Distortion Plus
Noise

Signal-to-Noise Ratio SNR

Half-Bridge Switch
On-Resistance

Switch Rise and Fall Times No load (Note 4) 50 ns

IN_ Input Bias Current -1 +1 µA

MID Input Bias Current I

Shutdown-to-Full Operation t

Power-On to Full Operation t

Thermal-Overload Threshold
Temperature

Short-Circuit Output Current I

Click-and-Pop K

DIGITAL INPUTS (SHDN) (Note 9)

Logic-Input Low Voltage V

Logic-Input High Voltage V

Input Leakage Current -1 +1 µA

THD+N

R

DS(ON

MID

SON

PU

T

SH

SC

CP

IL

IH

f

= 1kHz,

IN

RL = 8Ω, P

= 3.5W 0.06

OUT

BW = 22Hz to 22kHz
(Notes 5, 6, and 7)

P

= 9.5W, RL = 8Ω,

OUT

= 4Ω, P

L

Unweighted 88

= 5W 0.08

OUT

R

BW = 22Hz to 22kHz
(Notes 5 and 6)

A-weighted 93

0.4 0.7 Ω

VDD = 24V, no load 50 µA

68 ms

V

= 3.3V 1.5 s

SHDN

Junction temperature 150

OUT_ shorted to VDD or V

P eak vol tag e, 32- sam p l es

SS

Into shutdown -38

2.9 4.5 A

p er second , A- w ei g hted
( N otes 4 and 8)

Out of shutdown -40

0.4 V

2.4 V

%

dB

o

C

dBV

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

P osi ti ve S up p l y V ol tag e Rang eVDD(Note 3) 10 20 V

N eg ati ve S up p l y V ol tag e
Rang e

Positive Supply Mute Mode
Current

Negative Supply Mute Mode
Current

V

(Note 3) -20 -10 V

SS

No load, V

No load, V

SFT

SFT

= 0V (outputs not switching) 8 11 mA

= 0V (outputs not switching) -12 -8 mA

MAX9742

Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS—Dual Supplies (continued)

(VDD= 15V, VSS= V

SUB

= -15V, V

SHDN

= 3.3V, V

MID

= LGND = 0V, C

VDD

= C

VSS

= 1000µF, C

BYP

= 1µF, C

SFT

= 0.22µF, C

FB_1

=

150pF, C

FB_2

= 10pF, C

BOOT

= 0.1µF, C

REGP

= C

REGM

= 1µF, R

IN_

= 30.1kΩ, R

F1A

= 121kΩ, R

F1B

= 562kΩ, RF2= 681kΩ, R

REF

=

68kΩ, R

L

= ∞, TA= T

MIN

to T

MAX

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

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Positive Supply Current I

Negative Supply Current I

Positive Supply Shutdown
Current

Negative Supply Shutdown
Current

Output Offset Voltage

IN_ Input Bias Current -1 +1 µA

Power-Supply Rejection Ratio
(Note 4)

Crosstalk
(Notes 5 and 6)

Continuous Output Power P

Efficiency
(Notes 5, 6, and 7)

Total Harmonic Distortion
Plus Noise

Signal-to-Noise Ratio SNR

Shutdown-to-Full Operation t

Short-Circuit Output Current I

Click-and-Pop K

DD

SS

No load, output filter removed 23 36 mA

No load, output filter removed -36 -23 mA

No load, V

No load, V

Output referred, affected by R

= 0V 0.001 1 µA

SHDN

= 0V -1 -0.03 µA

SHDN

and R

IN_

F_

tolerances (Note 4)

VDD = 10V to 20V 97

PSRR

VSS = -10V to -20V 100

VDD = 15V + 500mV

= -15V + 500mV

V

SS

L to R, R to L, R

, f = 1kHz 67

P-P

, f = 1kHz 64

P-P

= 8Ω, P

L

= 1W, f = 1kHz -61 dB

OUT

RL = 8Ω 14

RL = 8Ω, VDD = 18V,
V

= -18V

SS

= 4Ω, VDD = 12V,

R

L

V

= -12V

SS

= 15W, THD+N = 10% 93 %

RL = 8Ω, P

R

= 4Ω, P

L

= 5W 0.06

OUT

= 10W 0.08

OUT

Unweighted 89

A-weighted 94

SS

Into shutdown -36

Out of shutdown -36

OUT

THD+N

SON

SC

CP

fIN = 1kHz,
THD+N = 10%
(Notes 5, 6, and 7)

= 8Ω, P

R

L

f

= 1kHz,

IN

OUT

BW = 22Hz to 22kHz
(Notes 5, 6, and 7)

P

= 14W,

OUT

= 8Ω, BW = 22Hz to

R

L

22kHz (Notes 5 and 6)

OUT_ shorted to VDD or V

P eak vol tag e, 32- sam p l es
p er second , A- w ei g hted
( N otes 4 and 8)

530mV

21

9.5

68 ms

2.9 4.5 A

dB

dB

dBV

W

%

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

_______________________________________________________________________________________ 5

Note 2: All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 3: Supply pumping may occur at high output powers with low audio frequencies. Use proper supply bypassing to prevent the

device from entering overvoltage protection due to supply pumping. See the

Supply Pumping Effects

and the

Supply

Undervoltage and Overvoltage Protection

sections.

Note 4: Amplifier inputs AC-coupled to ground.
Note 5: For R

L

= 4Ω, LF= 22µH and CF= 0.68µF. For RL= 6Ω, LF= 33µH and CF= 0.47µF. For RL= 8Ω, LF= 47µH and CF=

0.33µF.

Note 6: Testing performed with four-layer PCB.
Note 7: Both channels driven in phase.
Note 8: Testing performed with an 8Ω resistor connected between LC filter output and ground. Mode transitions are controlled by

SHDN. K

CP

level is calculated as 20log[(peak voltage during mode transition, no input signal) / 1V

RMS

].

Note 9: Digital input specifications apply to both single-supply and dual-supply operation.
Note 10: Channels driven 180° out-of-phase. Load connected between LC filter outputs.
Note 11: L

F

= 22µH and CF= 0.68µF.

Note 12: Testing performed with an 8Ω resistor connected between LC filter outputs. Mode transitions are controlled by SHDN. K

CP

level is calculated as 20log[(peak voltage during mode transition, no input signal) / 1V

RMS

].

ELECTRICAL CHARACTERISTICS—Single-Supply, BTL Configuration

(VDD= 24V, VSS= V

SUB

= LGND = 0V, V

SHDN

= 3.3V, V

MID

= 12V, C

VDD

= 660µF, C

MID1

= 10µF, C

MID2

= 10µF, R1 = R2 = R3 =

10kΩ, C

SFT

= 0.47µF, C

OUT

= 1000µF, C

FB_1

= 150pF, C

FB_2

= 10pF, C

BOOT

= 0.1µF, C

REGP

= C

REGM

= 1µF, R

IN_

= 30.1kΩ, R

F1A

= 121kΩ, R

F1B

= 562kΩ, RF2= 681kΩ, R

REF

= 68kΩ, RL= ∞, TA= T

MIN

to T

MAX

, unless otherwise noted. Typical values are at TA=

+25°C.) (Note 2)

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Output Offset Voltage (Note 4) 7 mV

Power-Supply Rejection Ratio
(Note 4)

Continuous Output Power P

Efficiency

Total Harmonic Distortion Plus
Noise (Notes 6, 10, and 11)

Signal-to-Noise Ratio SNR

Shutdown-to-Full Operation t

Click-and-Pop K

PSRR

OUT

THD+N

SON

CP

VDD = 20V to 40V 88

= 24V + 500mV

V

DD

, f = 1kHz 77

P-P

RL = 8Ω, fIN = 1kHz, THD+N = 10%,
(Notes 6, 10, and 11)

R

= 8Ω, P

L

= 10W, THD+N = 10%,

OUT

(Notes 5 and 6)

fIN = 1kHz, BW = 22Hz to 22kHz,

= 8Ω, P

R

L

P

= 32W, RL = 8Ω,

OUT

BW = 22Hz to 22kHz
(Notes 6, 10, and 11)

P eak vol tag e, 32- sam p l es

OUT

= 10W

Unweighted 90

A-weighted 96

Into shutdown -47

p er second , A- w ei g hted
( N otes 4, 11, and 12)

Out of shutdown -32

32 W

83 %

0.08 %

68 ms

dB

dB

dBV

MAX9742

Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs

6 _______________________________________________________________________________________

Typical Operating Characteristics

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc01

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

15105

0.1

1

10

100

0.01
020

SINGLE SUPPLY
V

DD

= 24V

f = 1kHz

RL = 8

Ω

RL = 6

Ω

RL = 4

Ω

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc02

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

302010

0.1

1

10

100

0.01
040

SINGLE SUPPLY
V

DD

= 32V

f = 1kHz

RL = 8

Ω

RL = 6

Ω

THERMALLY
LIMITED

RL = 4

Ω

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc03

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

302010

0.1

1

10

100

0.01
040

SINGLE SUPPLY
V

DD

= 36V

f = 1kHz

RL = 8

Ω

RL = 6

Ω

THERMALLY
LIMITED

RL = 4

Ω

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc04

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

302010

0.1

1

10

100

0.01
040

SINGLE SUPPLY
V

DD

= 40V

f = 1kHz

RL = 8

Ω

RL = 6

Ω

THERMALLY
LIMITED

RL = 4

Ω

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc05

OUTPUT POWER (W)

THD+N (%)

302010

0.1

1

10

100

0.01
05040

BTL
CONFIGURATION
V

DD

= 24V

R

L

= 8

Ω

f = 1kHz

VDD = 24V

VDD = 36V

THERMALLY
LIMITED

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc06

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

15105

0.1

1

10

100

0.01
020

DUAL SUPPLY
R

L

= 8

Ω

f = 1kHz

f = 100Hz

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc07

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

2010

0.1

1

10

100

0.01
03015525

DUAL SUPPLY
R

L

= 4

Ω

f = 1kHz

f = 100Hz

THERMALLY LIMITED

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc08

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

105

0.1

1

10

100

0.01
015

SINGLE SUPPLY
V

DD

= 24V

R

L

= 8

Ω

f = 1kHz

f = 100Hz

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

MAX9742 toc09

OUTPUT POWER PER CHANNEL (W)

THD+N (%)

105

0.1

1

10

100

0.01
02015

SINGLE SUPPLY
V

DD

= 24V

R

L

= 4

Ω

f = 1kHz

f = 100Hz

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

_______________________________________________________________________________________

7

Typical Operating Characteristics (continued)

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

BTL CONFIGURATION

= 24V

V

DD

Ω

= 8

R

L

10

1

f = 1kHz

THD+N (%)

0.1

0.01

0.001
04030

OUTPUT POWER (W)

f = 100Hz

2010

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

BTL CONFIGURATION

= 24V

V

DD

Ω

= 8

R

L

10

T

= 40°C

A

MAX9742 toc10

MAX9742 toc13

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

SINGLE SUPPLY

= 24V

V

DD

Ω

= 8

R

L

10

= 40°C

T

A

1

THD+N (%)

f = 1kHz

0.1

f = 100Hz

0.01
015

OUTPUT POWER PER CHANNEL (W)

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

DUAL SUPPLY

Ω

= 8

R

L

10

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. OUTPUT POWER

100

SINGLE SUPPLY

= 24V

V

MAX9742 toc11

THD+N (%)

105

DD

Ω

= 8

R

L

10

= 40°C

T

A

1

f = 1kHz

0.1

f = 100Hz

0.01
02015

OUTPUT POWER PER CHANNEL (W)

105

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

DUAL SUPPLY

Ω

= 4

R

MAX9742 toc14

L

10

MAX9742 toc12

MAX9742 toc15

1

f = 1kHz

THD+N (%)

0.1

0.01

0.001
04030

f = 100Hz

2010

OUTPUT POWER (W)

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

SINGLE SUPPLY

= 24V

V

DD

Ω

= 8

R

L

10

P

= 5W

1

THD+N (%)

0.1

0.01

0.001
100 100k

OUT

FREQUENCY (Hz)

P

= 3W

OUT

10k1k

MAX9742 toc16

1

THD+N (%)

0.1

0.01
100 100k

P

= 8W

OUT

FREQUENCY (Hz)

P

= 4W

OUT

10k1k

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

SINGLE SUPPLY

= 24V

V

DD

Ω

= 4

R

L

10

P

= 9W

1

THD+N (%)

0.1

0.01

0.001
100 100k

OUT

P

FREQUENCY (Hz)

OUT

= 5W

10k1k

MAX9742 toc17

P

= 13W

1

THD+N (%)

0.1

0.01
100 100k

OUT

P

OUT

FREQUENCY (Hz)

= 8W

10k1k

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

100

BTL CONFIGURATION

= 24V

V

DD

Ω

= 8

R

L

10

P

= 17W

1

THD+N (%)

0.1

0.01

0.001
100 100k

OUT

P

FREQUENCY (Hz)

OUT

= 12W

10k1k

MAX9742 toc18

MAX9742

Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

10

SINGLE SUPPLY

= 24V

V

DD

Ω

= 8

R

1

THD+N (%)

0.1

P

L
OUT

= 50mW

MAX9742 toc19

10

1

THD+N (%)

0.1

TOTAL HARMONIC DISTORTION

PLUS NOISE vs. FREQUENCY

SINGLE SUPPLY

= 24V

V

DD

Ω

= 4

R

L

= 50mW

P

OUT

TOTAL HARMONIC DISTORTION PLUS NOISE vs.

OUTPUT POWER WITH AND WITHOUT T-NETWORK

100

SINGLE SUPPLY

= 24V

V

10

1

THD+N (%)

0.1

DD

Ω

= 8

R

L

f = 1kHz

WITHOUT T-NETWORK

MAX9742 toc20

MAX9742 toc21

0.01
100 100k

FREQUENCY (Hz)

10k1k

EFFICIENCY AND POWER

DISSIPATION vs. OUTPUT POWER

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

015

EFFICIENCY

SYSTEM POWER
DISSIPATION

510

OUTPUT POWER PER CHANNEL (W)

EFFICIENCY AND POWER

DISSIPATION vs. OUTPUT POWER

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

EFFICIENCY

SYSTEM POWER
DISSIPATION

015

510

OUTPUT POWER PER CHANNEL (W)

0.01
100 100k

MAX9742 toc22

SINGLE SUPPLY

= 30V

V

DD

Ω

= 8

R

L

= 1kHz

f

IN

MAX9742 toc24

SINGLE SUPPLY

= 24V

V

DD

= 8Ω

R

L

= 1kHz

f

IN

FREQUENCY (Hz)

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5
POWER DISSIPATION (W)

1.0

0.5

0

2.5

2.0

1.5

1.0

POWER DISSIPATION (W)

0.5

0

10k1k

0.01

0.001 100

WITH T-NETWORK

0.10.01 101

OUTPUT POWER PER CHANNEL (W)

EFFICIENCY AND POWER

DISSIPATION vs. OUTPUT POWER

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

020

EFFICIENCY

SYSTEM POWER
DISSIPATION

51015

OUTPUT POWER PER CHANNEL (W)

MAX9742 toc23

DUAL SUPPLY

Ω

= 8

R

L

= 1kHz

f

IN

5.0

4.5

4.0

3.5

3.0

2.5

2.0

1.5
POWER DISSIPATION (W)

1.0

0.5

0

EFFICIENCY AND POWER

DISSIPATION vs. OUTPUT POWER

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

EFFICIENCY

025

5101520

OUTPUT POWER PER CHANNEL (W)

MAX9742 toc25

SYSTEM POWER
DISSIPATION

SINGLE SUPPLY

= 24V

V

DD

= 4Ω

R

L

= 1kHz

f

IN

9

8

7

6

5

4

3

POWER DISSIPATION (W)

2

1

0

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

_______________________________________________________________________________________

9

Typical Operating Characteristics (continued)

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

100

90

80

70

60

50

40

EFFICIENCY (%)

30

20

10

0

EFFICIENCY AND POWER

DISSIPATION vs. OUTPUT POWER

EFFICIENCY

SYSTEM POWER
DISSIPATION

BTL CONFIGURATION
V

DD

R

L

f

IN

050

10 20 30 40

OUTPUT POWER (W)

= 24V

Ω

= 8
= 1kHz

MAX9742 toc26

10

9

8

7

6

5

4

3

POWER DISSIPATION (W)

2

1

0

OUTPUT POWER PER CHANNEL (W)

30

25

20

15

10

5

0

±

DUAL SUPPLY
R

L

10

OUTPUT POWER

vs. SUPPLY VOLTAGE

30

SINGLE SUPPLY

Ω

= 8

R

L

25

20

15

10

OUTPUT POWER PER CHANNEL (W)

5

0

20 4035

10% THD+N

3025

SUPPLY VOLTAGE (V)

MAX9742 toc29

1% THD+N

30

SINGLE SUPPLY
R

L

25

10% THD+N

20

15

10

OUTPUT POWER PER CHANNEL (W)

5

0

20 4035

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

20

15

10

5

0

-5

SUPPLY CURRENT (mA)

-10

-15

-20

I

DD

±10 ±20±18±14

DUAL SUPPLY
OUTPUT FILTER REMOVED
NO LOAD CONNECTED

= |VSS|

V

DD

I

SS

±16±12

SUPPLY VOLTAGE (V)

MAX9742 toc32

18

SINGLE SUPPLY
OUTPUT FILTER REMOVED

17

INPUTS GROUNDED
NO LOAD CONNECTED

16

15

14

SUPPLY CURRENT (mA)

13

12

20 4030

OUTPUT POWER

vs. SUPPLY VOLTAGE

Ω

= 8

10% THD+N

±

±

14

12

SUPPLY VOLTAGE (V)

OUTPUT POWER

vs. SUPPLY VOLTAGE

Ω

= 4

1% THD+N

SUPPLY VOLTAGE (V)

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

SUPPLY VOLTAGE (V)

3025

OUTPUT POWER

vs. SUPPLY VOLTAGE

25

MAX9742 toc27

20

10% THD+N

15

1% THD+N

±

12

10

SUPPLY VOLTAGE (V)

1% THD+N

±

16

10

5

OUTPUT POWER PER CHANNEL (W)

0

±

±

20

18

±

OUTPUT POWER

vs. SUPPLY VOLTAGE

45

BTL CONFIGURATION

MAX9742 toc30

OUTPUT POWER (W)

40

35

30

25

20

15

10

Ω

= 8

R

L

10% THD+N

5

0

20 302824

SUPPLY VOLTAGE (V)

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

10

MAX9742 toc33

3525

0

-10

-20

-30

SUPPLY CURRENT (nA)

-40

-50

-60
±10 ±22±18 ±20±12 ±16

I

SS

±14

SUPPLY VOLTAGE (V)

±

±

14

16

1% THD+N

2622

I

DD

DUAL SUPPLY

= |VSS|

V

DD

OUTPUT FILTER REMOVED
INPUTS GROUNDED
NO LOAD CONNECTED

DUAL SUPPLY

Ω

= 4

R

L

±

18

MAX9742 toc28

±

20

MAX9742 toc31

MAX9742 toc34

MAX9742

Single-/Dual-Supply, Stereo 16W,
Class D Amplifier with Differential Inputs

10 ______________________________________________________________________________________

Typical Operating Characteristics (continued)

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

1.0

SINGLE SUPPLY
INPUTS AC GROUNDED
NO LOAD CONNECTED

0.8

0.6

0.4

SUPPLY CURRENT (mA)

0.2

0

-20

MAX9742 toc35

-40

-60

-80

OUTPUT AMPLITUDE (dBV)

-100

WIDEBAND OUTPUT SPECTRUM

RBW = 10kHz
MEASURED AT SINGLE­ENDED FILTER OUTPUT
INPUTS AC GROUNDED

OUTPUT SPECTRUM FFT

0

SINGLE SUPPLY

Ω

= 8

R

L

-20

= 1kHz

MAX9742 toc36

f

IN

= -60dBV

V

OUT_

-40

-60

-80

OUTPUT AMPLITUDE (dBV)

-100

MAX9742 toc37

0

20 4025 35

SUPPLY VOLTAGE (V)

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

0

DUAL SUPPLY

Ω

= 8

R

L

-10

-20

-30

-40

PSRR (dB)

-50

VSS = -15V + 500mV

-60

-70

-80

10 100k100

FREQUENCY (Hz)

CROSSTALK vs. FREQUENCY

0

DUAL SUPPLY

-10

= 8Ω

R

L

= 1W

P

OUT

-20

-30

-40

-50

CROSSTALK (dB)

-60

-70

-80

-90

R INTO L

L INTO R

10 100k100

FREQUENCY (Hz)

30

P-P

VDD = 15V + 500mV

1k 10k

1k 10k

MAX9742 toc39

-120
0 20k5k

FREQUENCY (Hz)

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

0

BTL

-10

= 24V + 500mV

V

-20

-30

-40

-50

PSRR (dB)

-60

-70

-80

-90

-100

DD

Ω

RL = 8

10 100k100

P-P

FREQUENCY (Hz)

10k 15k

MAX9742 toc40

1k 10k

-120

0.1 1001.0
FREQUENCY (MHz)

10

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY

20

SINGLE SUPPLY

= 24V + 500mV

V

DD

0

Ω

MAX9742 toc38

P-P

RL = 8

-20

-40

PSRR (dB)

-60

-80

-100

-120
10 100k

P-P

OUT_ PSRR

MID PSRR

10k1k100

FREQUENCY (Hz)

EXITING SHUTDOWN

MAX9742 toc41

CROSSTALK vs. FREQUENCY

20

SINGLE SUPPLY

= 8Ω

R

L

0

= 1W

P

OUT

-20

-40

-60

CROSSTALK (dB)

-80

-100

-120
10 100k

R INTO L

L INTO R

FREQUENCY (Hz)

DUAL SUPPLY

V

SHDN

2V/div

V

OUT_

20V/div

V

OUT_

5V/div

R

MAX9742 toc42

FILTERED

10k1k100

= 8Ω

L

(DUAL SUPPLY)

20ms/div

MAX9742 toc43

MAX9742

Single-/Dual-Supply, Stereo 16W,

Class D Amplifier with Differential Inputs

______________________________________________________________________________________

11

Typical Operating Characteristics (continued)

(24V single-supply mode, ±15V dual-supply mode, both channels driven in phase, THD+N measurement bandwidth = 22Hz to
22kHz, T

A

= +25°C, unless otherwise noted. See Figure 1 for test circuits, see

Typical Application Circuits/Functional Diagrams

for

test circuit component values.)

ENTERING SHUTDOWN

DUAL SUPPLY

= 8Ω

R

L

V

SHDN

2V/div

V

OUT_

20V/div

FILTERED

V

OUT_

5V/div

10ms/div

CASE TEMPERATURE

vs. OUTPUT POWER

50

40

30

20

CASE TEMPERATURE (°C)

10

0

012462

OUTPUT POWER PER CHANNEL (W)

MAX9742 toc44

SINGLE SUPPLY

= 24V

V

DD

= 8Ω

R

L

4-LAYER PCB

810

FILTERED

MAX9742 toc47

V

SHDN

2V/div

V

OUT_

10V/div

V

OUT_

5V/div

CASE TEMPERATURE (°C)

120

100

80

60

40

20

0

0205

EXITING SHUTDOWN

SINGLE SUPPLY

= 8Ω

R

L

20ms/div

CASE TEMPERATURE

vs. OUTPUT POWER

SINGLE SUPPLY

= 24V

V

DD

= 4Ω

R

L

4-LAYER PCB

10 15

OUTPUT POWER PER CHANNEL (W)

ENTERING SHUTDOWN

MAX9742 toc45

V

SHDN

2V/div

V

OUT_

10V/div

FILTERED

V

OUT_

5V/div

(SINGLE SUPPLY)

SINGLE SUPPLY
R

10ms/div

= 8Ω

L

OUTPUT WAVEFORM

SINGLE SUPPLY, VDD = 24V

V

OUT

10V/div

V

OUTR

10V/div

INPUTS AC GROUNDED

1µs/div

MAX9742 toc48

MAX9742 toc46

MAX9742 toc49

EMI AMPLITUDE vs. FREQUENCY

40

SINGLE SUPPLY

= 8Ω, P

OUT

18.1dBµV/m
BELOW LIMIT

100
FREQUENCY (MHz)

= 1.25W

EN55022B LIMIT

12.8dBµV/m
BELOW LIMIT

R

L

35

SPEAKER CABLE
LENTH = 1m

30

9.4dBµV/m BELOW LIMIT

25

20

AMPLITUDE (dBµV/m)

15

10

5

30 1000

MAX9742 toc50

AMPLITUDE (dBµV/m)

EMI AMPLITUDE vs. FREQUENCY

40

SINGLE SUPPLY

= 4Ω, P

R

L

35

SPEAKER CABLE
LENTH = 1m

30

25

7dBµV/m

20

BELOW
LIMIT

15

10

5

30 1000

= 1.25W

OUT_

11.3dBµV/m
BELOW LIMIT

100
FREQUENCY (MHz)

MAX9742 toc51

EN55022B LIMIT

7.8dBµV/m
BELOW LIMIT

5.8dBµV/m
BELOW LIMIT

3.6dBµV/m
BELOW LIMIT