Rainbow Electronics MAX9820 User Manual

General Description

The MAX9820 Windows Vista®-compliant stereo head­phone amplifier is designed for portable equipment
where board space is at a premium. It features Maxim’s
patented DirectDrive

®

architecture to produce a
ground-referenced output from a single supply, elimi­nating the large output-coupling capacitors required by
conventional single-supply headphone amplifiers.

The MAX9820 features an undervoltage lockout that
prevents over discharging of the battery during
brownout conditions, click-and-pop suppression that
eliminates audible transients on startup, a low-power
shutdown mode, and thermal-overload and short-circuit
protection. Additionally, the MAX9820 suppresses RF
radiation received by input and supply traces acting as
antennas and prevents the amplifier from demodulating
the coupled noise.

The MAX9820 is available in a 10-pin TDFN package
(3mm x 3mm x 0.8mm) and specified over the -40°C to
+85°C extended temperature range.

Applications

Cell Phones

MP3 Players

Notebook PCs

PDAs

Features

o Clickless/Popless Operation

o High RF Noise Rejection

o Windows Vista Premium Mobile Compliant

o 2.7V to 5.5V Single-Supply Operation

o 95mW Output Power (32Ω, V

DD

= 5V)

o Low-Current Shutdown Mode, < 1µA

o Low 3mA (V

DD

= 3.3V) Quiescent Current

o Space-Saving, 3mm x 3mm, 10-Pin TDFN Package

MAX9820

DirectDrive Headphone Amplifier

with External Gain

________________________________________________________________

Maxim Integrated Products

1

19-4666; Rev 0; 7/09

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

EVALUATION KIT

AVAILABLE

Pin Configuration

Ordering Information

+

Denotes a lead(Pb)-free/RoHS-compliant package.

*

EP = Exposed pad.

Simplified Block Diagram

Windows Vista is a registered trademark of Microsoft Corp.

DirectDrive is a registered trademark of Maxim Integrated Products, Inc.

PART TEMP RANGE

MAX9820ETB+ -40°C to +85°C 10 TDFN-EP* AUU

PIN-

PACKAGE

TOP MARK

TOP VIEW

C1P

1

C1N

29

V

3

SS

OUTL

4

56

*EXPOSED PAD.

MAX9820

*EP

TDFN

GND

10

SHDN

V

8

DD

INL

7

INROUTR

LEFT

AUDIO

INPUT

RIGHT
AUDIO
INPUT

MAX9820

SHDN

DirectDrive OUTPUTS

ELIMINATE DC-BLOCKING

CAPACITORS

MAX9820

DirectDrive Headphone Amplifier
with External Gain

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VDD= V

SHDN

= 5V, V

GND

= 0V, RIN= RFB= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R

LOAD

= ∞, TA= -40°C to +85°C,

unless otherwise noted. Typical values are at T

A

= +25°C, unless otherwise noted.) (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 GND..............................................................-0.3V to +6V

C1P to GND................................................-0.3V to (V

DD

+ 0.3V)

C1N to GND ................................................(V

SS

- 0.3V) to +0.3V

V

SS

to GND...............................................................-6V to +0.3V

OUTR, OUTL to GND.............................................................±3V

SHDN to GND...........................................................-0.3V to +6V

INR, INL to GND.........................................-0.3V to (V

DD

+ 0.3V)

OUTR, OUTL Short Circuit to GND, V

DD

....................Continuous

Short Circuit Between OUTL and OUTR ....................Continuous

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

Continuous Power Dissipation (T

A

= +70°C)

10-Pin TDFN Single-Layer PCB (derate 18.5mW/°C

above +70°C)........................................................1481.5mW

Junction-to-Case Thermal Resistance (θ

JC

) (Note 1)

10-Pin TDFN ................................................................8.5°C/W

Junction-to-Ambient Thermal Resistance (θ

JA

) (Note 1)

10-Pin TDFN...............................................................41.0°C/W

Continuous Power Dissipation (T

A

= +70°C)

10-Pin TDFN Multilayer PCB (derate 24.4mW/°C

above +70°C)...........................................................1951mW

Junction-to-Case Thermal Resistance (θ

JC

) (Note 1)

10-Pin TDFN.................................................................9.0°C/W

Junction-to-Ambient Thermal Resistance (θ

JA

) (Note 1)

10-Pin TDFN...............................................................41.0°C/W

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

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

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

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

Note 1: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-

layer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial

.

GENERAL

Supply Voltage Range V

Undervoltage Lockout UVLO 2.2 V

Quiescent Current I

Shutdown Current I

Output Signal Attenuation in
Shutdown

Output Impedance in
Shutdown

Turn-On Time t

Output Offset Voltage V

Click-and-Pop Level K

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

DD

DD

SHDNVSHDN

ON

OS

CP

Guaranteed by PSRR test 2.7 5.5 V

VDD = 3.3V 3.0 4.6

VDD = 5V 4.0 6.0

= 0V, TA = +25°C < 0.1 1 µA

V

= 0V, VIN = 1V

SHDN

V

= 0V 0.6 kΩ

SHDN

TA = +25°C (Note 3) ±0.1 ±0.5 mV

Z

= 32Ω + 1µH, peak

LOAD

voltage, A-weighted, 32 samples
per second (Notes 3, 4)

Z

= 10kΩ, peak voltage,

LOAD

A-weighted, 32 samples per
second (Notes 3, 4)

RMS

, R

= 10kΩ -110 dBV

LOAD

Into shutdown -79

Out of
shutdown

Into shutdown -62

Out of
shutdown

0.56 ms

-77

-58

mA

dBV

MAX9820

DirectDrive Headphone Amplifier

with External Gain

_______________________________________________________________________________________ 3

ELECTRICAL CHARACTERISTICS (continued)

(VDD= V

SHDN

= 5V, V

GND

= 0V, RIN= RFB= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R

LOAD

= ∞, TA= -40°C to +85°C,

unless otherwise noted. Typical values are at T

A

= +25°C, unless otherwise noted.) (Note 2)

Note 2: All specifications are 100% tested at T

A

= +25°C; temperature limits are guaranteed by design.

Note 3: The amplifier inputs are AC-coupled to GND.
Note 4: Mode transitions are controlled by SHDN.

Power-Supply Rejection Ratio PSRR

Output Power P

Total Harmonic Distortion
Plus Noise

Signal-to-Noise Ratio SNR Z

Output Noise V

Crosstalk

Capacitive Load Drive C

Oscillator Frequency f

Thermal Shutdown 145 °C

Thermal Shutdown Hysteresis 15 °C

DIGITAL INPUT (SHDN)

Input Voltage High V

Input Voltage Low V

Input Leakage Current I

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

OUT

THD+N

NOISE

L

OSC

INH

INL

LEAKAGE TA

V

= 2.7V to 5.5V, TA = +25°C (Note 3) 75 90

DD

f = 1kHz, 200mV

f = 20kHz, 200mV

Z

= 32Ω + 1µH, f = 1kHz,

LOAD

THD+N = 1%

Z

= 16Ω + 1µH, f = 1kHz,

LOAD

THD+N = 1%

Z

= 16Ω + 1µH, f = 1kHz, P

LOAD

Z

= 32Ω + 1µH, f = 1kHz, P

LOAD

Z

= 10kΩ, f = 1kHz, V

LOAD

= 32Ω + 1µH, P

LOAD

(Note 3) 73

P-P

(Note 3) 55

P-P

VDD = 3.6V 45

= 5.0V 95

V

DD

VDD = 3.6V 32

= 5.0V 75

V

DD

= 20mW 0.014

OUT

= 20mW 0.005

OUT

= 1V

OUT

= 25mW, A-weighted 105 dB

OUT

RMS

A-weighted (Note 3) 9 µV

Z

= 32Ω + 1µH

LOAD

L to R, R to L,
BW = 20Hz to 15kHz

FS = 0.300V
V

OUT

Z

LOAD

FS = 0.707V
V

OUT

RMS

= 30mV

= 10kΩ

RMS

= 70.7mV

RMS

No sustained oscillations 200 pF

TA = +25°C 300 500 800 kHz

= +25°C ±1 µA

,

,

RMS

0.001

73

73

1.2 V

0.3 V

dB

mW

%

dB

MAX9820

DirectDrive Headphone Amplifier
with External Gain

4 _______________________________________________________________________________________

Typical Operating Characteristics

(VDD= V

SHDN

= 5V, V

GND

= 0V, RIN= RFB= 40.2kΩ (gain = -1V/V), C1 = C2 = 1µF, C3 = 10µF, R

LOAD

= ∞. Typical values are at T

A

= +25°C, unless otherwise noted.)

10

1

THD+N vs. OUTPUT POWER

V

= 5.0V

DD

I

R
L

LOAD

LOAD

= 16
= 1FH

MAX9820 toc01

0.1

THD+N (%)

f = 100Hz

f = 6kHz

10

1

0.1

THD+N (%)

THD+N vs. OUTPUT POWER

V

= 5.0V

DD

I

R

= 32

LOAD

L

= 1FH

LOAD

f = 100Hz

MAX9820 toc02

f = 6kHz

0.01

0.001
0 0.14

OUTPUT POWER (W)

f = 1kHz

THD+N vs. OUTPUT POWER

10

V

= 3.6V

DD

I

R

= 16

LOAD

= 1FH

L

LOAD

1

f = 100Hz

0.1

THD+N (%)

0.01

0.001

OUTPUT POWER (W)

f = 1kHz

THD+N vs. FREQUENCY

10

V

= 5.0V

DD

I

R

= 16

LOAD

L

= 1FH

LOAD

1

0.120.100.080.060.040.02

f = 6kHz

0.050.040.030.020.010 0.06

MAX9820 toc03

MAX9820 toc05

0.01

0.001
0 0.16

OUTPUT POWER (W)

f = 1kHz

THD+N vs. OUTPUT POWER

10

V

= 3.6V

DD

I

R

= 32

LOAD

= 1FH

L

LOAD

1

0.1

THD+N (%)

0.01

0.001

f = 100Hz

f = 1kHz

OUTPUT POWER (W)

THD+N vs. FREQUENCY

10

V

= 5.0V

DD

I

R

= 32

LOAD

L

= 1FH

LOAD

1

0.140.120.100.080.060.040.02

MAX9820 toc04

f = 6kHz

0.070.060.050.040.030.020.010 0.08

MAX9820 toc06

0.1

THD+N (%)

0.01

0.001

P

= 20mW

OUT

FREQUENCY (Hz)

P

= 60mW

OUT

10,000100010010 100,000

0.1

THD+N (%)

0.01

0.001

P

OUT

= 20mW

FREQUENCY (Hz)

P

= 60mW

OUT

10,000100010010 100,000