Rainbow Electronics MAX9758 User Manual

General Description

The MAX9756/MAX9757/MAX9758 combine dual, 2.3W,
bridge tied load (BTL) stereo audio power amplifiers and
a DirectDriveTMheadphone amplifier in a single device.
These devices feature single-supply voltage operation,
shutdown mode, logic-selectable gain, a headphone
sense input, a 31-step analog volume control, and indus­try-leading click-and-pop suppression. The headphone
amplifier uses Maxim’s patent-pending DirectDrive archi­tecture that produces a ground-referenced output from a
single supply, eliminating the need for large DC-blocking
capacitors.

The MAX9756/MAX9757 feature automatic level control
(ALC) that automatically limits output power to the speak­er in the event of an overpowered output.

The MAX9756/MAX9758s’ 150mA internal linear regula­tor provides a complete solution for DAC- or CODEC­based designs.

The MAX9756/MAX9757/MAX9758 are offered in space­saving, thermally efficient 32-pin (5mm x 5mm x 0.8mm)
and 36-pin thin QFN (6mm x 6mm x 0.8mm) packages.
All devices are specified over the extended -40°C to
+85°C temperature range.

Features

♦ Automatic Level Control—Protects Speakers

♦ Analog Volume Control

♦ 120mW DirectDrive Headphone Amplifiers (16Ω)

♦ 150mA Adjustable LDO

♦ Class AB, 2.3W, Stereo BTL Speaker Amplifiers

(3Ω)

♦ High 95dB PSRR

♦ Low-Power Shutdown Mode

♦ Industry-Leading Click-and-Pop Suppression

♦ Short-Circuit and Thermal Protection

♦ Beep Input

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

________________________________________________________________ Maxim Integrated Products 1

VOL

ALC

SINGLE SUPPLY 4.5V TO 5.5V

SINGLE SUPPLY 4.5V TO 5.5V SINGLE SUPPLY 4.5V TO 5.5V

1.2V TO 5V

HPS

BEEP

MAX9756

LDO

ALC

VOL

ALC

HPS

BEEP

MAX9757

ALC

VOL

1.2V TO 5V

HPS

BEEP

MAX9758

LDO

Simplified Block Diagrams

Ordering Information

Applications

PART

LDO PIN-PACKAGE

MAX9756ETX+

√√36 Thin QFN-EP**

MAX9757ETJ+*

√ — 32 Thin QFN-EP**

MAX9758ETJ+*

— √ 32 Thin QFN-EP**

19-3782; Rev 0; 8/05

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

Notebook PCs
Tablet PCs
Portable DVD

Players

Flat-Panel TVs
PC Displays
LCD Projectors
Portable Audio

Note: All devices specified for -40°C to +85°C operating
temperature range.

+Denotes lead-free package.
*Future product—contact factory for availability.
**EP = Exposed paddle.

ALC

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(V

DD

= PVDD= HPVDD= CPV

DD

= IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, C

BIAS

= 1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load

terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (A

V(SP)

= 15dB, A

V(HP)

= 0dB), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at T

A

= +25°C.) (Note 1)

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, CPVDD, IN to GND) ....+6V

PGND, CPGND to GND ......................................................±0.3V

CPVSS, C1N, VSSto GND......................................-6.0V to +0.3V

HP_ to GND ...........................................................................±3V

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

DD

+ 0.3V)

Duration of OUT_ Short Circuit to GND or PVDD........Continuous

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

Duration of HP_ Short Circuit to GND,

VSS, or HPVDD.........................................................Continuous

Duration of OUT Short Circuit to GND........................Continuous

Continuous Current (PVDD, OUT_, PGND) ...........................1.7A

Continuous Current (CPVDD, C1N, CPGND, C1P, CPVSS,

VSS, HPVDD, HP_, IN, OUT).............................................0.85A

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

Continuous Power Dissipation (TA= +70°C, single-layer board)

32-Pin Thin QFN (derate 18.6mW/°C above +70°C).....1490mW

36-Pin Thin QFN (derate 20.4mW/°C above +70°C).....1633mW

Continuous Power Dissipation (TA=+70°C, multilayer board)

32-Pin Thin QFN (derate 24.9mW/°C above +70°C).....1990mW

36-Pin Thin QFN (derate 27.7mW/°C above +70°C).....2180mW

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

PARAMETER

SYMBOL

CONDITIONS

MIN

TYP

MAX

UNITS

GENERAL

Supply Voltage Range

Inferred from PSRR test 4.5 5.5 V

Headphone Supply Voltage HPV

DD

Inferred from PSRR test 3.0 5.5 V

HPS = GND, speaker
mode, R

L

= ∞

14 29

Quiescent Supply Current I

DD

IDD = I

VDD

+

HPS = 5V, headphone
mode, R

L

= ∞

713

mA

Shutdown Supply Current I

SHDN

SHDN = REGEN = GND 0.2 5 µA

Bias Voltage V

BIAS

2.2

V

Switching Time t

SW

Gain or input switching 10 µs

Input Resistance R

IN

INL and INR 10 20 30 kΩ

Turn-On Time t

SON

25 ms

SPEAKER AMPLIFIERS (HPS = GND)

Output Offset Voltage V

OS

Measured between OUT_+ and OUT_-,
T

A

= +25°C

mV

PVDD = 4.5V to 5.5V, TA = +25°C 75 95

f = 1kHz, V

RIPPLE

= 200mV

P-P

83

Power-Supply Rejection Ratio
(Note 2)

PSRR

f = 10kHz, V

RIPPLE

= 200mV

P-P

68

dB

RL = 8Ω 0.9 1.3

RL = 4Ω 2.0

Output Power (Note 3) P

OUT

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

A

= +25°C)

R

L

= 3Ω 2.3

W

RL = 8Ω, BTL P

OUT

= 1W, f = 1kHz

Total Harmonic Distortion Plus
Noise

RL = 4Ω, BTL P

OUT

= 1W, f = 1kHz

%

RL = 8Ω, BTL P

OUT

= 1W, BW = 22Hz to

22kHz, unweighted

92

Signal-to-Noise Ratio SNR

R

L

= 8Ω, BTL P

OUT

= 1W, A weighted 95

dB

VDD, PV

DD

I

HPVDD

+ I

CPVDD

THD+N

2.43 2.65

±0.4 ±15

0.009

0.015

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(V

DD

= PVDD= HPVDD= CPV

DD

= IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, C

BIAS

= 1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load

terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (A

V(SP)

= 15dB, A

V(HP)

= 0dB), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at T

A

= +25°C.) (Note 1)

PARAMETER

CONDITIONS

UNITS

Noise V

n

BW = 22Hz to 22kHz, unweighted,
measured at output, input at AC GND

71

µV

RMS

Capacitive-Load Drive C

L

No sustained oscillations

pF

Crosstalk L to R, R to L, f = 10kHz 80 dB

Slew Rate SR Measured between OUT_+ and OUT_- 1.3 V/µs

GAIN3 = 0 GAIN2 = 0 GAIN1 = 0 15

GAIN3 = 0 GAIN2 = 0 GAIN1 = 1

GAIN3 = 0 GAIN2 = 1 GAIN1 = 0 18

GAIN3 = 0 GAIN2 = 1 GAIN1 = 1

GAIN3 = 1 GAIN2 = 0 GAIN1 = 0 21

GAIN3 = 1 GAIN2 = 0 GAIN1 = 1

GAIN3 = 1 GAIN2 = 1 GAIN1 = 0

Gain (Maximum Volume Settings)

(Note 4)

A

VMAX

(SPKR)

GAIN3 = 1 GAIN2 = 1 GAIN1 = 1

dB

Into
shutdown

65

Click-and-Pop Level K

CP

Peak voltage, 32
samples/second,
A weighted (Note 5)

Out of
shutdown

dBV

HEADPHONE AMPLIFIERS (HPS = VDD)

Output Offset Voltage

)

TA = +25°C ±2 ±7 mV

HPVDD = 3V to 5.5V, TA = +25°C 70 90

f = 1kHz, V

RIPPLE

= 200mV

P-P

72

Power-Supply Rejection Ratio
(Note 2)

PSRR

f = 10kHz, V

RIPPLE

= 200mV

P-P

70

dB

RL = 32Ω 40 68

Output Power (Note 3) P

OUT

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

A

= +25°C)

R

L

= 16Ω

mW

RL = 32Ω, V

OUT

= 1V

RMS

, f = 1kHz

Total Harmonic Distortion Plus
Noise

RL = 16Ω, V

OUT

= 1V

RMS

, f = 1kHz

%

RL = 32Ω, BTL P

OUT

= 65mW,

BW = 22Hz to 22kHz, unweighted

97

Signal-to-Noise Ratio SNR

R

L

= 32Ω, BTL P

OUT

= 65W,

BW = 22Hz to 22kHz, A weighted

dB

Noise V

n

BW = 22Hz to 22kHz

µV

RMS

Capacitive-Load Drive C

L

No sustained oscillations

pF

Crosstalk L to R, R to L, f = 10kHz 60 dB

Slew Rate SR 1.4 V/µs

GAIN2 = 0, HPS = 1 0

Gain (Maximum Volume Settings)
(Note 6)

)

GAIN2 = 1, HPS = 1 3.0

dB

Into shutdown 62

Click-and-Pop Level K

CP

Peak voltage, 32
samples/second,
A weighted (Note 4)

50

dBV

SYMBOL

MIN TYP MAX

200

16.5

19.5

22.5

24.0

25.5

38.5

V

OS(HP

THD+N

A

VMAX(HP

130

0.02

0.04

100

20.4

200

Out of shutdown

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control

4 _______________________________________________________________________________________

ELECTRICAL CHARACTERISTICS (continued)

(V

DD

= PVDD= HPVDD= CPV

DD

= IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, C

BIAS

= 1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load

terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (A

V(SP)

= 15dB, A

V(HP)

= 0dB), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at T

A

= +25°C.) (Note 1)

PARAMETER

CONDITIONS

UNITS

CHARGE PUMP

Charge-Pump Frequency f

OSC

kHz

VOLUME CONTROL

VOL Input Impedance R

VOL

MΩ

VOL Input Hysteresis 10 mV

Full Mute Voltage (Note 7)

0.858 x
V

Full Mute Attenuation fIN = 1kHz -85 dB

Input Impedance R

VOL_

Any gain setting

MΩ

AV = +15dB to 0dB

AV = -2dB to -20dB

Channel Matching

A

V

= -22dB to -56dB

dB

BEEP INPUT

Beep Signal Amplitude Threshold

TA = +25°C, RB = 47kΩ (see BEEP Input
section)

0.3 V

Beep Signal Frequency
Threshold

T

A

= +25°C

Hz

AUTOMATIC LEVEL CONTROL SPEAKER AMPLIFIER (MAX9756/MAX9757)

PREF Threshold Accuracy R

PREF

= 180kΩ 5 8.1 %

Maximum Gain Compression 6.0 6.3 dB

Attack Time CT = 1µF (Note 8) 15 ms

Hold Time Time between attack and release phases 50 ms

0V < VDR < (0.3V x VDD)30

9.5Release Time (Note 9)

C

T

= 1µF,
release from
6dB

0.8V < V

DR

< V

DD

3

s

DR INPUT (TRI-STATE INPUT)

DR Input Voltage High V

DRH

0.8 x
V

DR Input Voltage Middle V

DRM

0.4 x

0.6 x
V

DR Input Voltage Low V

DRL

0

0.3 x
V

Input Leakage Current 0V ≤ VDR ≤ V

DD

±1 µA

LOGIC INPUTS (GAIN_, SHDN, REGEN)

Input High Voltage V

IH

2V

Input Low Voltage V

IL

0.8 V

Input Leakage Current I

IN

±1 µA

SYMBOL

MIN TYP MAX

500 550 600

100

300

V

DD

V

DD

HPV

100

±0.2

±0.3

±1.0

DD

0.4V < VDR < (0.6V x VDD)

V

DD

V

DD

V

DD

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

_______________________________________________________________________________________ 5

Note 1: All devices are 100% production tested at room temperature. All temperature limits are guaranteed by design.
Note 2: PSRR is specified with the amplifier input connected to GND through R

IN

and CIN.

Note 3: Output power levels are measured with the TQFN’s exposed paddle soldered to the ground plane.
Note 4: Speaker path gain is defined as: A

VSPKR

= (V

OUT+

- V

OUT-

)/V

IN__

).

Note 5: Speaker mode testing performed with 8Ω resistive load connected across BTL output. Headphone mode testing per-

formed with 32Ω resistive load connected between HP_ and GND. Mode transitions are controlled by SHDN.

Note 6: Headphone path gain is defined as: A

VHP

= V

HP_/VIN__

.

Note 7: See Table 3 for detains on the mute levels.
Note 8: Attack envelope is exponential. Attack time is defined as the 15 x 10

3

x CT.

Note 9: Time for the gain to return to within 10% of nominal gain setting after the input signal has fallen below the PREF threshold.

Release is linear in dB. Release time is proportional to magnitude of gain compression.

Note 10: Dropout voltage is defined as (V

IN

- V

OUT

) when V

OUT

is 2% below the value of V

OUT

for VIN= V

OUT(NOM)

+ 1V.

ELECTRICAL CHARACTERISTICS (continued)

(V

DD

= PVDD= HPVDD= CPV

DD

= IN = +5.0V, GND = PGND = CPGND = 0, SHDN = VDD, REGEN = VDD, DR = SET = GND, C

BIAS

= 1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, speaker loads terminated between OUT_+ and OUT_-, headphone load

terminated between HP_ and GND, GAIN1 = GAIN2 = GAIN3 = VOL = 0 (A

V(SP)

= 15dB, A

V(HP)

= 0dB), TA= -40°C to +85°C, unless

otherwise noted. Typical values are at T

A

= +25°C.) (Note 1)

PARAMETER

CONDITIONS

UNITS

LOGIC INPUT HEADPHONE (HPS)

Input High Voltage V

IH

2V

Input Low Voltage V

IL

0.8 V

HPS Pullup Current 35 µA

LOW-DROPOUT LINEAR REGULATOR

Input Voltage Range V

IN

Inferred from line regulation 3.5 5.5 V

I

OUT

= 0mA, SHDN = GND

Supply (Ground) Current I

Q

I

OUT

= 150mA

µA

Shutdown Current I

SHDN

REGEN = 0V 0.1 3 µA

Output Current I

OUT

mA

Fixed Output Voltage Accuracy I

OUT

= 1mA

%

Adjustable Output Voltage Range

V

SET Reference Voltage V

SET

V

SET Dual-Mode Threshold

mV

SET Input Leakage Current I

SET

nA

I

OUT

= 50mA 25 50

Dropout Voltage (Note 10) ΔV

OD

V

OUT

= 4.65V (fixed

output operation)

I

OUT

= 150mA

mV

Output Current Limit I

LIM

mA

Startup Time 20 µs

Line Regulation

V

IN

= 3.5V to 5.5V, V

OUT

= 2.5V,

I

OUT

= 1mA

%/V

Load Regulation V

OUT

= 4.65V, 1mA < I

OUT

< 150mA 0.5 %

f = 1kHz 60

Ripple Rejection V

RIPPLE

= 200mV

P-P

f = 10kHz 50

dB

Output Voltage Noise

20Hz to 22kHz, C

OUT

= 2 x 1µF,

I

OUT

= 150mA, V

OUT

= 4.65V

µV

RMS

SYMBOL

MIN TYP MAX

100 160

350

150

V

SET

1.19 1.21 1.23

200

±20 ±500

100 150

-0.1 +0.01 +0.1

300

100

±1.5

4.85

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control

6 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= PVDD= HPVDD= CPVDD= IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, C

BIAS

=

1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to

22kHz, TA = +25°C, unless otherwise noted.)

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc01

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 5V
R

L

= 3

Ω

OUTPUT POWER = 500mW

OUTPUT POWER = 1.8W

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc02

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 5V
R

L

= 4

Ω

OUTPUT POWER = 500mW

OUTPUT POWER = 1.5W

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc03

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 5V
R

L

= 8

Ω

OUTPUT POWER = 500mW

OUTPUT POWER = 1W

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9756 toc04

OUTPUT POWER (W)

THD+N (%)

3.02.52.01.51.00.5

0.01

0.1

1

10

100

0.001

03.5

VDD = 5V
R

L

= 3

Ω

fIN = 100Hz

fIN = 1kHz

fIN = 10kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9756 toc05

OUTPUT POWER (W)

THD+N (%)

3.02.52.01.51.00.5

0.01

0.1

1

10

100

0.001
0 3.5

VDD = 5V
R

L

= 4

Ω

fIN = 100Hz

fIN = 1kHz

fIN = 10kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (SPEAKER MODE)

MAX9756 toc06

OUTPUT POWER (W)

THD+N (%)

1.51.00.5

0.01

0.1

1

10

100

0.001
0 2.0

VDD = 5V
R

L

= 8

Ω

fIN = 100Hz

fIN = 1kHz

fIN = 10kHz

OUTPUT POWER

vs. LOAD RESISTANCE (SPEAKER MODE)

MAX9756 toc07

LOAD RESISTANCE (Ω)

OUTPUT POWER (W)

10

0.5

1.0

1.5

2.0

2.5

3.0

0

1100

VDD = 5V
f = 1kHz

THD+N = 10%

THD+N = 1%

POWER DISSIPATION vs. OUTPUT POWER

(SPEAKER MODE)

MAX9756 toc08

OUTPUT POWER (W)

POWER DISSIPATION (W)

3.53.02.52.01.51.00.5

0.5

1.0

1.5

2.0

2.5

3.0

0

0 4.0

f = 1kHz
P

OUT

= P

OUTL

+ P

OUTR

RL = 8

Ω

RL = 4

Ω

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (SPEAKER MODE)

MAX9756 toc09

FREQUENCY (Hz)

PSRR (dB)

10k1k100

-110

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-120
10 100k

V

RIPPLE

= 200mV

P-P

RL = 8

Ω

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

_______________________________________________________________________________________ 7

CROSSTALK vs. FREQUENCY

(SPEAKER MODE)

MAX9756 toc10

FREQUENCY (Hz)

CROSSTALK (dB)

10k1k100

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-110
10 100k

LEFT TO RIGHT

RIGHT TO LEFT

VIN = 200mV

P-P

TURN-ON RESPONSE (SPEAKER MODE)

MAX9756 toc11

10ms/div

SHDN
5V/div

OUT_+
2V/div

OUT_­2V/div

OUT_+ - OUT_­50mV/div

TURN-OFF RESPONSE (SPEAKER MODE)

MAX9756 toc12

10ms/div

SHDN
5V/div

OUT_+
2V/div

OUT_­2V/div

OUT_+ - OUT_­50mV/div

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc13

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 5V
R

L

= 16

Ω

OUTPUT POWER = 100mW

OUTPUT POWER = 40mW

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc14

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 5V
R

L

= 32

Ω

OUTPUT POWER = 20mW

OUTPUT POWER = 60mW

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc15

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 3.3V
R

L

= 16

Ω

OUTPUT POWER = 80mW

OUTPUT POWER = 20mW

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc16

FREQUENCY (Hz)

THD+N (%)

10k1k100

0.01

0.1

1

10

0.001
10 100k

VDD = 3.3V
R

L

= 32

Ω

OUTPUT POWER = 50mW

OUTPUT POWER = 20mW

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9756 toc17

OUTPUT POWER (mW)

THD+N (%)

18016014012010080604020

0.01

0.1

1

10

100

0.001
0200

HPVDD = 5V
R

L

= 16

Ω

fIN = 100Hz

fIN = 10kHz

fIN = 1kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9756 toc18

OUTPUT POWER (mW)

THD+N (%)

908070605040302010

0.01

0.1

1

10

100

0.001
0100

HPVDD = 5V
R

L

= 32

Ω

fIN = 100Hz

fIN = 10kHz

fIN = 1kHz

Typical Operating Characteristics (continued)

(VDD= PVDD= HPVDD= CPVDD= IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, C

BIAS

=

1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to

22kHz, TA = +25°C, unless otherwise noted.)

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control

8 _______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VDD= PVDD= HPVDD= CPVDD= IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, C

BIAS

=

1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to

22kHz, TA = +25°C, unless otherwise noted.)

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9756 toc19

OUTPUT POWER (mW)

THD+N (%)

10080604020

0.01

0.1

1

10

100

0.001
0120

HPVDD = 3.3V
R

L

= 16

Ω

fIN = 100Hz

fIN = 10kHz

fIN = 1kHz

TOTAL HARMONIC DISTORTION PLUS NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

MAX9756 toc20

OUTPUT POWER (mW)

THD+N (%)

80 907040 50 60

301020

0.01

0.1

1

10

100

0.001
0 100

HPVDD = 3.3V
R

L

= 32

Ω

fIN = 100Hz

fIN = 1kHz

fIN = 10kHz

OUTPUT POWER vs. LOAD RESISTANCE

(HEADPHONE MODE)

MAX9756 toc21

LOAD RESISTANCE (Ω)

OUTPUT POWER (mW)

100

20

40

60

80

100

120

140

0

10 1000

HPVDD = 3.3V
f = 1kHz

THD+N = 10%

THD+N = 1%

OUTPUT POWER vs. LOAD RESISTANCE

(HEADPHONE MODE)

MAX9756 toc22

LOAD RESISTANCE (Ω)

OUTPUT POWER (mW)

100

20

40

60

80

100

120

140

160

180

200

0

10 1000

HPVDD = 5V
f = 1kHz

THD+N = 10%

THD+N = 1%

POWER DISSIPATION vs. OUTPUT POWER

(HEADPHONE MODE)

MAX9756 toc23

OUTPUT POWER (mW)

POWER DISSIPATION (mW)

225200175150125100755025

0.2

0.4

0.6

0.8

0

0 250

f = 1kHz
P

OUT

= PHL + P

HR

RL = 16

Ω

RL = 32

Ω

OUTPUT POWER vs. SUPPLY VOLTAGE

(HEADPHONE MODE)

MAX9756 toc24

SUPPLY VOLTAGE (V)

OUTPUT POWER (mW)

5.04.54.03.5

10

20

30

40

50

60

70

80

90

100

110

120

130

140

0

3.0 5.5

RL = 16

Ω

RL = 32

Ω

THD+N = 1%

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (HEADPHONE MODE)

MAX9756 toc25

FREQUENCY (Hz)

PSRR (dB)

10k1k100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100
10 100k

V

RIPPLE

= 100mV

P-P

INPUTS AC-GROUNDED

HPVDD = 5V

HPVDD = 3.3V

CROSSTALK vs. FREQUENCY

(HEADPHONE MODE)

MAX9756 toc26

FREQUENCY (Hz)

CROSSTALK (dB)

1010.1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-110

0.01 100

RL = 32

Ω

f = 1kHz
V

IN

= 200mV

P-P

RIGHT TO LEFT

LEFT TO RIGHT

OUTPUT POWER vs. CHARGE-PUMP
CAPACITANCE (HEADPHONE MODE)

MAX9756 toc27

LOAD (Ω)

OUTPUT POWER (mW)

3025

20

15

35 40

45

40
30

50

60

70

80

90

100

120

110

130

140

150

20

10 50

C1 = C2 = 1μF

C1 = C2 = 2.2μF

f = 1kHz
THD+N = 1%

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive

Headphone Amplifiers with Automatic Level Control

_______________________________________________________________________________________ 9

TURN-ON RESPONSE (HEADPHONE MODE)

MAX9756 toc28

10ms/div

SHDN
5V/div

HPR
10mV/div

HPL
10mV/div

TURN-OFF RESPONSE (HEADPHONE MODE)

MAX9756 toc29

10ms/div

SHDN
5V/div

HPR
10mV/div

HPL
10mV/div

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

MAX9756 toc30

SUPPLY VOLTAGE (V)

SUPPLY CURRENT (mA)

5.35.14.94.7

8

11

14

17

20

5

4.5 5.5

HPS = GND

HPS = V

DD

SHUTDOWN CURRENT

vs. SUPPLY VOLTAGE

MAX9756 toc31

SUPPLY VOLTAGE (V)

SHUTDOWN CURRENT (nA)

5.35.14.7 4.9

100

200

300

400

500

600

0

4.5 5.5

POWER LIMITING OF SINE BURST

(FAST ATTACK AND FAST RELEASE)

MAX9756 toc32

10ms/div

OUTPUT
2V/div

CT
1V/div

POWER LIMITING OF SINE BURST

(FAST ATTACK AND SLOW RELEASE)

MAX9756 toc33

40ms/div

OUTPUT
2V/div

CT
1V/div

POWER LIMITING OF SINE BURST

(SLOW ATTACK AND SLOW RELEASE)

MAX9756 toc33

2s/div

OUTPUT
2V/div

CT
1V/div

LDO OUTPUT VOLTAGE ACCURACY

vs. LOAD CURRENT

MAX9756 toc35

LOAD CURRENT (mA)

DEVIATION (%)

12510025 50 75

-1.5

-1.0

-0.5

0

0.5

1.0

1.5

2.0

-2.0
0150

Typical Operating Characteristics (continued)

(VDD= PVDD= HPVDD= CPVDD= IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, C

BIAS

=

1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to

22kHz, TA = +25°C, unless otherwise noted.)

MAX9756/MAX9757/MAX9758

2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control

10 ______________________________________________________________________________________

Typical Operating Characteristics (continued)

(VDD= PVDD= HPVDD= CPVDD= IN = +5.0V, GND = PGND = CPGND = 0V, SHDN = VDD, REGEN = DR = SET = GND, C

BIAS

=

1µF, C

PVSS

= 1µF, C1 = C2 = 1µF, PREF = unconnected, GAIN1 = 1, GAIN2 = GAIN3 = VOL = 0V, measurement BW = 22Hz to

22kHz, TA = +25°C, unless otherwise noted.)

LDO OUTPUT VOLTAGE ACCURACY

vs. TEMPERATURE

MAX7956 toc37

TEMPERATURE (°C)

DEVIATION (%)

603510-15

-4

-3

-2

-1

0

1

2

3

4

5

-5

-40 85

DROPOUT VOLTAGE

vs. LOAD CURRENT

MAX9756 toc38

LOAD CURRENT (mA)

DROPOUT VOLTAGE (V)

125100755025

-200

-100

0

100

200

300

-300
0150

POWER-SUPPLY REJECTION RATIO

vs. FREQUENCY (LDO)

MAX9756 toc39

FREQUENCY (Hz)

PSRR (dB)

10k1k100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-100
10 100k

V

RIPPLE

= 100mV

P-P

LDO OUTPUT NOISE

MAX9756 toc40

200μs/div

LDO_OUT
1mV/div

CROSSTALK vs. FREQUENCY

(LDO)

MAX9756 toc36

FREQUENCY (Hz)

CROSSTALK (dB)

1010.1

-100

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

-110

0.01 100

RL = 4

Ω

P

OUT(SPK)

= 1W

I

OUT

= 90mA

I

OUT

= 10mA

I

OUT

= 50mA