MAX9879

Stereo Class D Audio Subsystem

with DirectDrive Headphone Amplifier

11

Maxim Integrated

Typical Operating Characteristics (continued)

(VDD = VPVDDL = VPVDDR = 3.7V, VCCIO = 1.8V, VGND = VPGNDL = VPGNDR = 0. Single-ended inputs, preamp = 0dB, volume con-

trols = 0dB, BYPASS = 0, SHDN = 1. Speaker loads connected between OUT_+ and OUT_-. Headphone loads connected from HPL

or HPR to GND. RSPK = ∞, RHP = ∞. C1 = C2 = CBIAS = 1µF. TA = +25°C, unless otherwise noted.)

MAX9879 toc21

2ms/div

SCL

2V/div

OUT+ - OUT-

1V/div

SDA

2V/div

HEADPHONE AMPLIFIERS (Speaker Disabled)

TOTAL HARMONIC DISTORTION + NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

OUTPUT POWER (mW)

20

80

40

0.1

1

0.01

10

0.001

060

100

VDD = 3.7V

RL = 16

Ω

fIN = 100Hz

fIN = 1kHz

fIN = 6kHz

TOTAL HARMONIC DISTORTION + NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

OUTPUT POWER (mW)

40

30

50

0.1

10

0.01

100

0.001

020

70

10

60

VDD = 3.0V

RL = 32

Ω

fIN = 1kHz

fIN = 6kHz

fIN = 100Hz

TOTAL HARMONIC DISTORTION + NOISE

vs. OUTPUT POWER (HEADPHONE MODE)

OUTPUT POWER (mW)

40

30

50

0.1

10

0.01

100

0.001

020

60

10

VDD = 3.0V

RL = 16

Ω

fIN = 1kHz

fIN = 6kHz

fIN = 100Hz

TOTAL HARMONIC DISTORTION + NOISE

vs. FREQUENCY (HEADPHONE MODE)

FREQUENCY (kHz)

1

0.1

10

0.1

1

0.01

10

0.001

0.01

100

VDD = 3.0V

RL = 32

Ω

OUTPUT POWER = 30mW

OUTPUT POWER = 10mW

TOTAL HARMONIC DISTORTION + NOISE

vs. FREQUENCY (HEADPHONE MODE)

FREQUENCY (kHz)

1

0.1

10

0.1

1

0.01

10

0.001

0.01

100

VDD = 3.0V

RL = 16

Ω

OUTPUT POWER = 7mW

OUTPUT POWER = 22mW

TOTAL HARMONIC DISTORTION + NOISE

vs. FREQUENCY (HEADPHONE MODE)

FREQUENCY (kHz)

1

0.1

10

0.1

1

0.01

10

0.001

0.01

100

VDD = 3.7V

RL = 32

Ω

fIN = 1kHz

fIN = 6kHz

fIN = 100Hz

TOTAL HARMONIC DISTORTION + NOISE

vs. FREQUENCY (HEADPHONE MODE)

FREQUENCY (kHz)

10

1

0.1

0.01

0.1

1

10

0.001

0.01

100

VDD = 3.7V

RL = 32

Ω

OUTPUT POWER = 20mW

OUTPUT POWER = 45mW

TOTAL HARMONIC DISTORTION + NOISE

vs. FREQUENCY (HEADPHONE NOISE)

FREQUENCY (kHz)

1

0.1

10

0.1

1

0.01

10

0.001

0.01

100

VDD = 3.7V

RL = 16

Ω

OUTPUT POWER = 10mW

OUTPUT POWER = 40mW