Rainbow Electronics MAX9755 User Manual

General Description

The MAX9750/MAX9751/MAX9755 combine a stereo,

2.6W audio power amplifier and stereo DirectDrive
110mW headphone amplifier in a single device. The
headphone amplifier uses Maxim’s patented DirectDrive
architecture that produces a ground-referenced output
from a single supply, eliminating the need for large DC­blocking capacitors, saving cost, space, and component
height. A high 90dB PSRR and low 0.01% THD+N
ensures clean, low-distortion amplification of the audio
signal.

The MAX9750 features an analog volume control, and a
BEEP input. The MAX9751 features a 2:1 input multiplexer,
allowing multiple audio sources to be selected. All devices
feature a single-supply voltage, a shutdown mode, logic­selectable gain, and a headphone sense input. Industry­leading click-and-pop suppression eliminates audible
transients during power and shutdown cycles.

The MAX9750/MAX9751/MAX9755 are offered in space­saving, thermally efficient 28-pin thin QFN (5mm x 5mm
x 0.8mm) and 28-pin TSSOP packages. Both devices
have thermal-overload and output short-circuit protec­tion, and are specified over the extended -40°C to +85°C
temperature range.

Applications

Notebook PCs Flat-Panel TVs
Tablet PCs PC Displays
Portable DVD Players LCD Projectors

Features

♦ No DC-Blocking Capacitors Required—Provides

Industry’s Most Compact Notebook Audio
Solution

♦ PC2001 Compliant

♦ 5V Single-Supply Operation

♦ Class AB 2.6W Stereo BTL Speaker Amplifiers

♦ 110mW DirectDrive Headphone Amplifiers

♦ High 90dB PSRR

♦ Low-Power Shutdown Mode

♦ Industry-Leading Click-and-Pop Suppression

♦ Low 0.01% THD+N at 1kHz

♦ Short-Circuit and Thermal Protection

♦ Selectable Gain Settings

♦ Analog Volume Control (MAX9750)

♦ Beep Input with Glitch Filter (MAX9750)

♦ 2:1 Stereo Input MUX (MAX9751)

♦ ±8kV ESD-Protected Headphone Driver Outputs

♦ Available in Space-Saving, Thermally Efficient

Packages

28-Pin Thin QFN (5mm x 5mm x 0.8mm)
28-Pin TSSOP

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3006; Rev 1; 2/04

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.

PART

TEMP RANGE

PIN-

M A XIM U M

G A I N ( d B )

MAX9750AETI†

13.5

MAX9750AEUI*

28 TSSOP 13.5

MAX9750BETI†

19.5

MAX9750BEUI*

28 TSSOP 19.5

MAX9750CETI†

10.5

MAX9750CEUI*

28 TSSOP 10.5

MAX9751ETI†

10.5

MAX9751EUI*

28 TSSOP 10.5

MAX9755AETI†

10.5

MAX9755AEUI*

28 TSSOP 10.5

*Future product—contact factory for availability.

†

Lead-free package.

VOL

BEEP

MAX9750

Simplified Block Diagrams

Simplifed Block Diagrams continued at end of data sheet.

PACKAGE

-40°C to +85°C 28 Thi n QFN

-40°C to +85°C

-40°C to +85°C 28 Thi n QFN

-40°C to +85°C

-40°C to +85°C 28 Thi n QFN

-40°C to +85°C

-40°C to +85°C 28 Thi n QFN

-40°C to +85°C

-40°C to +85°C 28 Thi n QFN

-40°C to +85°C

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone 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.

Supply Voltage (VDD, PVDD, HPVDD, CPVDDto GND)..........+6V

GND to PGND.....................................................................±0.3V

CPV

SS

, C1N, VSSto GND .........................-6.0V to (GND + 0.3V)

HPOUT_ to GND....................................................................±3V

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

DD

+ 0.3V)

Duration of OUT_ Short Circuit to GND or PV

DD

........Continuous

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

Duration of HPOUT_ Short Circuit to GND,

V

SS

or HPVDD.........................................................Continuous

Continuous Current (PV

DD

, OUT_, PGND) ...........................1.7A

Continuous Current (CPV

DD

, C1N, C1P, CPVSS, VSS, HPVDD,

HPOUT_).......................................................................850mA

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

Continuous Power Dissipation (T

A

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

28-Pin TSSOP (derate 13mW/°C above +70°C) .........1039mW

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= PVDD= CPVDD= HPVDD= 5V, GND = PGND = CPGND = 0V, SHDN = VDD, C

BIAS

= 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = VOL = GAIN = 0V,
T

A

= T

MIN

to T

MAX

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

PARAMETER

CONDITIONS

UNITS

GENERAL

Supply Voltage Range

Inferred from PSRR test 4.5 5.5 V

Headphone Supply Voltage

CPV

DD

,

HPV

DD

Inferred from PSRR test 3 5.5 V

HPS = GND, speaker mode, RL = ∞ 14 29

Quiescent Supply Current I

DD

HPS = VDD, headphone mode, RL = ∞ 713

mA

Shutdown Supply Current I

SHDN

SHDN = GND 0.2 5 µA

Bias Voltage V

BIAS

1.7 1.8 1.9 V

Switching Time t

SW

Gain or input switching 10 µs

Input Resistance R

IN

Amplifier inputs (Note 2) 10 20 30 kΩ

Turn-On Time t

SON

25 ms

SPEAKER AMPLIFIER (HPS = GND)

MAX9750A/MAX9750B/
MAX9751/MAX9755

±1 ±15

Output Offset Voltage V

OS

Measured
between OUT_+
and OUT_-

MAX9750C

±6

mV

PVDD or VDD = 4.5V to 5.5V (TA = +25°C) 75 90
f = 1kHz, V

RIPPLE

= 200mV

P-P

80

Power-Supply Rejection Ratio
(Note 3)

PSRR

f = 10kHz, V

RIPPLE

= 200mV

P-P

55

dB

SYMBOL

VDD, PV

DD

MIN TYP MAX

±0.4

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD= CPVDD= HPVDD= 5V, GND = PGND = CPGND = 0V, SHDN = VDD, C

BIAS

= 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = VOL = GAIN = 0V,
T

A

= T

MIN

to T

MAX

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

PARAMETER

CONDITIONS

UNITS

MAX9750A/
MAX9750B/
MAX9751/
MAX9755

0.9 1.4

RL = 8Ω

0.8

MAX9750A/
MAX9750B/
MAX9751/
MAX9755

2.3

RL = 4Ω

1.2 1.5

MAX9750A/
MAX9750B/
MAX9751/
MAX9755

2.6

Output Power (Note 4) P

OUT

f = 1kHz,
T

A

= +25°C

R

L

= 3Ω

2.2

W

RL = 8Ω, P

OUT

= 500mW, f = 1kHz

Total Harmonic Distortion Plus
Noise

THD+N

R

L

= 4Ω, P

OUT

= 1W, f = 1kHz

%

Signal-to-Noise Ratio SNR

R

L

= 8Ω, P

OUT

= 500mW, BW = 22Hz to

22kHz

90 dB

Noise V

n

BW = 22Hz to 22kHz, A-weighted 80

µV

RMS

Capacitive-Load Drive C

L

No sustained oscillations

pF

Crosstalk L to R, R to L, f = 10kHz 75

Off-Isolation

Any unselected input to any active input,
f = 10kHz (MAX9751), input referred

75

dB

Slew Rate SR 1.4 V/µs

GAIN1 = 0, GAIN2 = 0 9
GAIN1 = 1, GAIN2 = 0
GAIN1 = 0, GAIN2 = 1 12

MAX9750A

GAIN1 = 1, GAIN2 = 1
GAIN1 = 0, GAIN2 = 0 15

GAIN1 = 1, GAIN2 = 0
GAIN1 = 0, GAIN2 = 1 18

MAX9750B

GAIN1 = 1, GAIN2 = 1
GAIN1 = 0, GAIN2 = 0 6
GAIN1 = 1, GAIN2 = 0 7.5
GAIN1 = 0, GAIN2 = 1 9

Gain (Maximum Volume Setting)

)

MAX9750C

GAIN1 = 1, GAIN2 = 1

dB

GAIN = 1 9

Gain (MAX9751/MAX9755) A

V

GAIN = 0

10.5

dB

SYMBOL

MAX9750C 0.65

THD+N = 1%,

A

VMAX(SPKR

MAX9750C

MAX9750C

MIN TYP MAX

0.01

0.02

200

10.5

13.5

16.5

19.5

10.5

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD= CPVDD= HPVDD= 5V, GND = PGND = CPGND = 0V, SHDN = VDD, C

BIAS

= 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = VOL = GAIN = 0V,
T

A

= T

MIN

to T

MAX

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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

HEADPHONE AMPLIFIER (HPS = VDD)

Output Offset Voltage V

OS

TA = +25°C ±2 ±7mV
HPVDD = 3V to 5.5V, TA = +25°C 60 75
f = 1kHz, V

RIPPLE

= 200mV

P-P

73

Power-Supply Rejection Ratio
(Note 3)

PSRR

f = 10kHz, V

RIPPLE

= 200mV

P-P

63

dB

RL = 32Ω 40 50

Output Power P

OUT

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

A

= +25°C

R

L

= 16Ω

mW

RL = 32Ω, P

OUT

= 20mW, f = 1kHz

Total Harmonic Distortion Plus
Noise

THD+N

R

L

= 16Ω, P

OUT

= 75mW, f = 1kHz

%

Signal-to-Noise Ratio SNR

R

L

= 32Ω, P

OUT

= 50mW, BW = 22Hz to

22kHz

95 dB

Noise V

n

BW = 22Hz to 22kHz 12

µV

RMS

Capacitive-Load Drive C

L

No sustained oscillations

pF

Crosstalk L to R, R to L, f = 10kHz 88

Off-Isolation

Any unselected input to any active input,
f = 10kHz (MAX9751), input referred

74

dB

Slew Rate SR 0.4 V/µs
ESD ESD IEC air discharge ±8 kV

GAIN2 = GAIN = 0, GAIN1 = X 0

Gain A

V

GAIN2 = GAIN = 1, GAIN1 = X 3

dB

CHARGE PUMP

Charge-Pump Frequency f

OSC

600 kHz

VOLUME CONTROL (MAX9750_)

VOL Input Impedance R

VOL

MΩ

VOL Input Hysteresis 10 mV

Full Mute Input Voltage (Note 5)

0.858 x
V

Channel Matching AV = -25dB to +13.5dB

dB

BEEP INPUT (MAX9750_)

Beep Signal Minimum Amplitude

V

BEEP

RB = 33kΩ (Note 6) 0.8 V

P-P

Beep Signal Minimum Frequency

f

BEEP

Hz

110

0.007

0.03

200

500 550

100

HPV

400

±0.2

DD

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

_______________________________________________________________________________________ 5

ELECTRICAL CHARACTERISTICS (continued)

(VDD= PVDD= CPVDD= HPVDD= 5V, GND = PGND = CPGND = 0V, SHDN = VDD, C

BIAS

= 1µF, C1 = C2 = 1µF, speaker load
terminated between OUT_+ and OUT_-, headphone load terminated between HPOUT_ and GND, GAIN1 = GAIN2 = VOL = GAIN = 0V,
T

A

= T

MIN

to T

MAX

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

PARAMETER

CONDITIONS

UNITS

LOGIC INPUT (SHDN, GAIN1, GAIN2, GAIN, VOL, IN1/2)

Logic Input High Voltage V

IH

2V

Logic Input Low Voltage V

IL

0.8 V

Logic Input Current I

IN

±1µA

LOGIC INPUT HEADPHONE (HPS)

Logic Input High Voltage V

IH

2V

Logic Input Low Voltage V

IL

0.8 V

Logic Input Current I

IN

10 µA

Note 1: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design.
Note 2: Guaranteed by design. Not production tested.
Note 3: PSRR is specified with the amplifier input connected to GND through C

IN

.

Note 4: Output power levels are measured with the thin QFN’s exposed paddle soldered to the ground plane.
Note 5: See Table 3 for details of the mute levels.
Note 6: The value of R

B

dictates the minimum beep signal amplitude (see the Beep Input section).

SYMBOL

MIN TYP MAX

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

6 _______________________________________________________________________________________

Typical Operating Characteristics

(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (SPEAKER MODE)

MAX9750/51 toc01

FREQUENCY (Hz)

THD+N (%)

VCC = 5V
R

L

= 3Ω

A

V

= 10.5dB

OUTPUT POWER = 1.5W

OUTPUT POWER = 500mW

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (SPEAKER MODE)

MAX9750/51 toc02

FREQUENCY (Hz)

THD+N (%)

VCC = 5V
R

L

= 4Ω

A

V

= 10.5dB

OUTPUT POWER = 1.25W

OUTPUT POWER = 500mW

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (SPEAKER MODE)

MAX9750/51 toc03

FREQUENCY (Hz)

THD+N (%)

VCC = 5V
R

L

= 8Ω

A

V

= 10.5dB

OUTPUT POWER = 100mW

OUTPUT POWER = 600mW

100

00.51.01.5 2.0 2.5 3.0

10

1

0.1

0.01

0.001

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc04

OUTPUT POWER (W)

THD+N (%)

VCC = 5V
R

L

= 3Ω

A

V

= 10.5dB

MAX9750C

fIN = 10kHz

fIN = 1kHz

fIN = 20Hz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc05

OUTPUT POWER (W)

THD+N (%)

3.53.02.52.01.51.00.5

0.01

0.1

1

10

100

0.001
0

VDD = 5V
A

V

= 13.5dB

R

L

= 3Ω

f = 1kHz

f = 10kHz

f = 20Hz

100

0

0.5

1.0 1.5

2.0

10

1

0.1

0.01

0.001

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc06

OUTPUT POWER (W)

THD+N (%)

fIN = 1kHz

fIN = 20Hz

VCC = 5V
R

L

= 4Ω

A

V

= 10.5dB

MAX9750C

fIN = 10kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc07

OUTPUT POWER (W)

THD+N (%)

2.52.01.51.00.5

0.01

0.1

1

10

100

0.001
0 3.0

VDD = 5V
A

V

= 13.5dB

R

L

= 4Ω

f = 1kHz

f = 10kHz

f = 20Hz

100

0

0.2 0.4 0.6

0.8 1.0

1.2

10

1

0.1

0.01

0.001

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc08

OUTPUT POWER (W)

THD+N (%)

fIN = 20Hz

fIN = 1kHz

fIN = 10kHz

VCC = 5V
R

L

= 8Ω

A

V

= 10.5dB

MAX9750C

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9750/51 toc09

OUTPUT POWER (W)

THD+N (%)

1.51.00.5

0.01

0.1

1

10

100

0.001
0

VDD = 5V
A

V

= 13.5dB

R

L

= 8Ω

f = 1kHz

f = 10kHz

f = 20Hz

Typical Operating Characteristics (continued)

(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

_______________________________________________________________________________________ 7

OUTPUT POWER

vs. LOAD RESISTANCE (SPEAKER MODE)

MAX9750/51 toc10

LOAD RESISTANCE (Ω)

OUTPUT POWER (W)

10

0.5

1.0

1.5

2.0

2.5

3.0

3.5

0

1 100

THD+N = 10%

THD+N = 1%

OUTPUT POWER

vs. LOAD RESISTANCE (SPEAKER MODE)

MAX9750/51 toc11

LOAD RESISTANCE (Ω)

OUTPUT POWER (W)

3.0

0

0.5

1.0

1.5

2.0

2.5

110100

THD+N = 10%

THD+N = 1%

VCC = 5V
f = 1kHz
A

V

= 10.5dB

MAX9750C

POWER DISSIPATION vs. OUTPUT POWER

(SPEAKER MODE)

MAX9750/51 toc12

OUTPUT POWER (W)

POWER DISSIPATION (W)

321

1

2

3

4

5

0

04

RL = 4Ω

RL = 8Ω

VDD = 5V
f = 1kHz
P

OUT

= P

OUTL

+ P

OUTR

POWER DISSIPATION vs. OUTPUT POWER

(SPEAKER MODE)

MAX9750/51 toc13

OUTPUT POWER (W)

POWER DISSIPATION (mW)

3.53.02.52.01.51.00.5

1

2

3

4

5

0

04.0

RL = 4Ω

RL = 8Ω

VDD = 5V
f = 1kHz
P

OUT

= P

OUTL

+ P

OUTR

MAX9750C

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (SPEAKER MODE)

MAX9750/51 toc14

FREQUENCY (Hz)

PSRR (dB)

10k1k100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100
10 100k

V

RIPPLE

= 200mV

P-P

AV = 10.5dB
OUTPUT REFERRED

0

-120
10 1k 10k100 100k

CROSSTALK vs. FREQUENCY

(SPEAKER MODE)

MAX9750/51 toc15

FREQUENCY (Hz)

CROSSTALK (dB)

-100

-110

-80

-90

-60

-70

-40

-50

-20

-10

-30

VCC = 5V
V

RIPPLE

= 200mV

P-P

RL = 4Ω

LEFT TO RIGHT

RIGHT TO LEFT

TURN-ON RESPONSE

(SPEAKER MODE)

MAX9750/51 toc16

20ms/div

SHDN

5V/div

2V/div

100mV/div

OUT_+

AND

OUT_-

OUT_+

- OUT_-

RL = 8Ω

Typical Operating Characteristics (continued)

(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

8 _______________________________________________________________________________________

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9750/51 toc19

THD+N (%)

VDD = 5V
R

L

= 32Ω

A

V

= 3dB

OUTPUT POWER = 45mW

OUTPUT POWER = 10mW

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9750/51 toc20

THD+N (%)

VDD = 3.3V
R

L

= 16Ω

A

V

= 3dB

OUTPUT POWER = 30mW

OUTPUT POWER = 10mW

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9750/51 toc21

THD+N (%)

VDD = 3.3V
R

L

= 32Ω

A

V

= 3dB

OUTPUT POWER = 45mW

OUTPUT POWER = 10mW

1000

100

10

1

0.1

0.01

0.001
075

100

12550

25

15

TOTAL HARMONIC DISTORTION PLUS NOIS

vs. OUTPUT POWER (HEADPHONE MODE

OUTPUT POWER (mW)

THD+N (%)

VDD = 5V
R

L

= 16Ω

A

V

= 3dB

f

IN

= 10kHz

f

IN

= 1kHz

f

IN

= 20Hz

1000

100

10

1

0.1

0.01

0.001
0608040

20

100

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9750/51 toc23

OUTPUT POWER (mW)

THD+N (%)

VDD = 5V
R

L

= 32Ω

A

V

= 3dB

f

IN

= 10kHz

f

IN

= 1kHz

f

IN

= 20Hz

1000

100

10

1

0.1

0.01

0.001
030

40

5020

10

60

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9750/51 toc24

OUTPUT POWER (mW)

THD+N (%)

VDD = 3.3V
R

L

= 16Ω

A

V

= 3dB

f

IN

= 10kHz

f

IN

= 1kHz

f

IN

= 20Hz

TURN-OFF RESPONSE

(SPEAKER MODE)

MAX9750/51 toc17

20ms/div

SHDN

5V/div

2V/div

20mV/div

OUT_+

AND

OUT_-

OUT_+

- OUT_-

RL = 8Ω

10

1

0.1

0.01

0.001

0.0001
10 1k 10k100 100k

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9750/51 toc18

FREQUENCY (Hz)

THD+N (%)

VDD = 5V
R

L

= 16Ω

A

V

= 3dB

OUTPUT POWER = 90mW

OUTPUT POWER = 30mW

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

_______________________________________________________________________________________ 9

OUTPUT POWER vs. SUPPLY VOLTAGE

(HEADPHONE MODE)

MAX9750/51 toc28

SUPPLY VOLTAGE (V)

OUTPUT POWER (mW)

5.04.54.03.5

25

50

75

100

125

0

3.0 5.5

RL = 16Ω

RL = 32Ω

f = 1kHz

10 1k 10k100 100k

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (HEADPHONE MODE)

MAX9750/51 toc29

FREQUENCY (Hz)

PSRR (dB)

V

RIPPLE

= 200mV

P-P

AV = 10.5dB
OUTPUT REFERRED

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100

10 100 1k 10k 100k

CROSSTALK vs. FREQUENCY

(HEADPHONE MODE)

MAX9750/51 toc30

FREQUENCY (Hz)

CROSSTALK (dB)

VCC = 5V
V

RIPPLE

= 200mV

P-P

RL = 32Ω

LEFT TO RIGHT

RIGHT TO LEFT

-100

-80

-60

-40

-20

0

-120

OUTPUT POWER vs. CHARGE-PUMP

CAPACITANCE AND LOAD RESISTANCE

MAX9750/51 toc31

LOAD RESISTANCE (Ω)

OUTPUT POWER (mW)

403020

20

40

60

80

100

120

140

160

180

200

0

10 50

VDD = 5V
f = 1kHz
THD+N = 1%

C1 = C2 = 2.2µF

C1 = C2 = 1µF

Typical Operating Characteristics (continued)

(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)

OUTPUT POWER vs. LOAD RESISTANCE

(HEADPHONE MODE)

MAX9750/51 toc26

LOAD RESISTANCE (Ω)

OUTPUT POWER (mW)

100

20

40

60

80

100

120

140

160

180

0

10 1000

THD+N = 10%

THD+N = 1%

(HEADPHONE MODE)

MAX9750/51 toc27

OUTPUT POWER (mW)

POWER DISSIPATION (mW)

225200150 17550 75 100 12525

25

50

75

100

125

150

175

200

225

250

0

0250

VDD = 5V
f = 1kHz
P

OUT

= P

OUTL

+ P

OUTR

R

L

= 16Ω

R

L

= 32Ω

1000

100

10

0.1

1

0.01

0.001
070

80

20 30

40

50

60

10

90

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9750/51 toc25

OUTPUT POWER (mW)

THD+N (%)

VDD = 3.3V
R

L

= 32Ω

A

V

= 3dB

f

IN

= 10kHz

f

IN

= 1kHz

f

IN

= 20Hz

MAX9750/MAX9751/MAX9755

2.6W Stereo Audio Power Amplifiers and
DirectDrive Headphone Amplifiers

10 ______________________________________________________________________________________

HEADPHONE OUTPUT SPECTRUM

MAX9750/51 toc32

FREQUENCY (Hz)

MAGNITUDE (dB)

15105

0

020

-120

-100

-80

-60

-40

-20

-140

VDD = 5V
f = 1kHz
V

OUT

= -60dB

R

L

= 32Ω

TURN-ON RESPONSE
(HEADPHONE MODE)

MAX9750/51 toc33

10ms/div

SHDN

5V/div

20mV/div

HPOUT_

RL = 32Ω

TURN-OFF RESPONSE

(HEADPHONE MODE)

MAX9750/51 toc34

10ms/div

SHDN

5V/div

20mV/div

HPOUT_

RL = 32Ω

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9750/51 toc35

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.255.004.75

4

2

6

8

12

10

14

16

18

0

4.50 5.50

HPS = GND

HPS = V

DD

SHUTDOWN SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9750/51 toc36

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (

µ

A)

5.255.004.754.50 5.50

0.05

0.10

0.15

0.20

0.25

0.30

0.35

0

Typical Operating Characteristics (continued)

(Measurement BW = 22Hz to 22kHz, TA = +25°C, unless otherwise noted.)