MAXIM MAX98306 Technical data

19-5919; Rev 1; 8/11

EVALUATION KIT

AVAILABLE

Stereo 3.7W Class D Amplifier

General Description

The MAX98306 stereo 3.7W Class D amplifier provides
Class AB audio performance with Class D efficiency.
This device offers five selectable gain settings (6dB,
9dB, 12dB, 15dB, and 18dB) set by a single gain-select
input (GAIN).

Active emissions limiting, edge-rate, and overshoot con­trol circuitry combined with a filterless spread-spectrum
modulation scheme (SSM) provide excellent EMI perfor­mance while eliminating the need for output filtering found
in traditional Class D devices. These features reduce
application component count.

The IC's 2.0mA quiescent current with a 3.7V supply
extends battery life in portable applications.

The IC is available in a 14-pin TDFN (3mm x 3mm x

0.75mm) package specified over the extended -40NC to
+85NC temperature range.

Applications

Smartphones

Tablets

Cellular Phones

Accessory Speakers

MP3 Players

Portable Audio Players

VoIP Phones

Typical Application Circuit

Features

S Output Power 3.7W at 3I, 10% THD, 1.7W at 8I,

10% THD, with 5V Supply

S Passes EMI Limit Unfiltered with Up to 12in of

Speaker Cable

S High 83dB PSRR at 217Hz

S Spread-Spectrum Modulation and Active

Emissions Limiting

S Five Pin-Selectable Gains

S Excellent Click-and-Pop Suppression

S Thermal and Overcurrent Protection

S Low-Current Shutdown Mode

S Space-Saving, 3mm x 3mm x 0.75mm,

14-Pin TDFN

Ordering Information

PART TEMP RANGE

MAX98306ETD+

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

-40NC to +85NC

PIN-

PACKAGE

14 TDFN +AEV

TOP

MARK

MAX98306

+2.6V TO +5.5V

0.1µF

1µF

INL+ OUTL+

1µF

INL-

PVDD

GAIN GAIN

1µF

INR+

1µF

INR-

PVDD

SHDN

_______________________________________________________________ Maxim Integrated Products 1

PVDD

CONTROL

MAX98306

PGND

10µF

OUTL-

OUTR+

OUTR-

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.

Stereo 3.7W Class D Amplifier

ABSOLUTE MAXIMUM RATINGS

Voltage

PVDD to PGND ....................................................-0.3V to +6V

OUTL+, OUTR+, OUTL-, OUTR-

to PGND ...........................................-0.3V to (V

All Other Pins to PGND .......................................-0.3V to +6V

Current

Continuous Current Into/Out of PVDD, PGND,

OUTL+, OUTR+, OUTL-, OUTR- .............................. ±800mA

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

MAX98306

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.

PVDD

+ 0.3V)

PACKAGE THERMAL CHARACTERISTICS (Note 1)

Junction-to-Ambient Thermal Resistance (qJA) ..............41°C/W

Junction-to-Case Thermal Resistance (qJA) .....................8°C/W

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.

Duration of Short Circuit

OUTL+, OUTR+, OUTL-, OUTR- to PGND or PVDD .... Continuous

OUTL+ to OUTL- or OUTR+ to OUTR- ...................Continuous

Continuous Power Dissipation for a MultiLayer Board (TA = +70°C)

TDFN (deration 24.4mW/°C above +70°C) ...............1951.2mW

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

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

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

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

Soldering Temperature (reflow) ......................................+260°C

ELECTRICAL CHARACTERISTICS

(V

= V

PVDD

AC measurement bandwidth, TA = T

GENERAL

Supply Voltage Range V
Undervoltage Lockout UVLO 1.8 2.3 V

Quiescent Supply Current I

Shutdown Supply Current I
Turn On Time t
Bias Voltage V

Voltage Gain A

Channel-to-Channel Gain
Tracking

Input Resistance R

Common-Mode Rejection Ratio CMRR fIN = 1kHz, input referred 79 dB
Output Offset Voltage V

= 3.7V, V

SHDN

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= 0V, AV = 12dB (GAIN = PVDD), RL = J, RL connected between OUT_+ to OUT_-, 20Hz to 22kHz

PGND

MIN

to T

PVDD

PVDD

SHDN

ON

BIAS

IN

OS

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

MAX

Guaranteed by PSRR test 2.6 5.5 V

V

= 3.7V 2 2.7

PVDD

V

= 5.0V 2.6

PVDD

V

= 0, TA = +25NC < 1 10 FA

SHDN

3.2 10 ms

1.62 V
GAIN = PGND 17.5 18 18.5
GAIN = 100kI to PGND 14.5 15 15.5
GAIN = PVDD 11.5 12 12.5

V

GAIN = 100kI to PVDD 8.5 9 9.5
GAIN = unconnected 5.5 6 6.5

AV = 18dB (GAIN = PGND) 22 33
AV = 15Db (GAIN = 100kI to PGND) 31 46
AV = 12dB (GAIN = PVDD) 44 65
AV = 9dB (GAIN = 100kI to PVDD) 62 93
AV = 6dB (GAIN = unconnected) 89 131

TA = +25NC (Note 3) ±1 ±3 mV

/2 2.15 V

PVDD

0.1 %

mA

dB

kI

2 ______________________________________________________________________________________

Stereo 3.7W Class D Amplifier

ELECTRICAL CHARACTERISTICS (continued)

(V

= V

PVDD

AC measurement bandwidth, TA = T

Click-and-Pop Level K

Power-Supply Rejection Ratio PSRR

Output Power P

Total Harmonic Distortion Plus
Noise

Output Noise A-weighted (Note 3) 29 FV

SHDN

= 3.7V, V

= 0V, AV = 12dB (GAIN = PVDD), RL = J, RL connected between OUT_+ to OUT_-, 20Hz to 22kHz

PGND

MIN

to T

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

MAX

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Into shutdown -79

Out of shutdown -73

V

= 2.6V to 5.5V,

PVDD

TA = +25NC

f = 217Hz, 200mV

P-P

ripple

f = 1kHz, 200mV

P-P

ripple

f = 10kHz, 200mV

P-P

ripple

Z

= 3I + 22FH,

SPK

V

= 5.0V

PVDD

Z

= 4I + 33FH,

SPK

V

= 5.0V

PVDD

Z

= 8I + 68FH,

SPK

V

= 5.0V

PVDD

Z

= 8I + 68FH,

SPK

V

= 3.7V

PVDD

Z

= 3I + 22FH,

SPK

V

= 5.0V

PVDD

Z

= 4I + 33FH,

SPK

V

= 5.0V

PVDD

Z

= 8I +68FH

SPK

V

= 5.0V

PVDD

Z

= 8I +68FH

SPK

V

= 3.7V

PVDD

Z

= 3I +22FH,

SPK

P

= 1.6W,

OUT

P

= 5.0V

VDD

Z

= 4I +33FH,

SPK

P

= 650mW,

OUT

P

= 3.7V

VDD

Z

= 4I +33FH,

SPK

P

= 1.3W,

OUT

V

= 5.0V

PVDD

Z

= 8I +68FH,

SPK

P

= 725mW,

OUT

P

= 5.0V

VDD

70 95

83

83

77

3.7

3

1.7

0.9

2.9

2.4

1.4

0.75

0.05

0.05 0.75

0.04

0.03

CP

OUT

THD+N

Peak voltage, TA = +25NC
A-weighted, 32 samples
per second (Notes 3, 4)

TA = +25NC
(Note 3)

THD+N = 10%

THD+N = 1%

fIN = 1kHz
TA = +25NC

MAX98306

dBV

dB

W

%

RMS

_______________________________________________________________________________________ 3

Stereo 3.7W Class D Amplifier

ELECTRICAL CHARACTERISTICS (continued)

(V

= V

PVDD

AC measurement bandwidth, TA = T

Signal-to-Noise Ratio SNR Z
Efficiency
Oscillator Frequency f
Spread-Spectrum Bandwidth 20 kHz

MAX98306

Current Limit TA = +25NC 3 A
Thermal-Shutdown Level +150 NC
Thermal Hysteresis 20 NC

DIGITAL INPUT (SHDN)

Input-Voltage High V
Input-Voltage Low V
Input Leakage Current TA = +25NC, SHDN = 0 ±1 FA

Note 2: This device is 100% production tested at TA = +25NC. All temperature limits are guaranteed by design.
Note 3: Amplifier inputs AC-coupled to ground.
Note 4: Specified at room temperature with an 8I resistive load in series with a 68µH inductive load.

SHDN

= 3.7V, V

= 0V, AV = 12dB (GAIN = PVDD), RL = J, RL connected between OUT_+ to OUT_-, 20Hz to 22kHz

PGND

MIN

to T

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

MAX

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

E

OSC

IH

IL

= 8I +68FH, P

SPK

Z

= 8I +68FH, P

SPK

at 1% THD+N 99 dB

OUT

= 1.4W, f = 1kHz 92 %

OUT

160 320 540 kHz

1.4 V

0.4 V

Typical Operating Characteristics

(V

= V

PVDD

bandwidth, TA = +25NC, unless otherwise noted.)

100

V
Z

10

1

THD+N (%)

0.1

0.01

0.001
0 1.00

= 5.0V, V

SHDN

PGND

THD+N vs. OUTPUT POWER

= 3.7V

PVDD

= 8I + 68µH

LOAD

f = 6kHz

f = 1kHz

f = 100kHz

OUTPUT POWER (W)

= 0V, AV = 12dB, RL = J, RL connected between OUT_+ to OUT_-, 20Hz to 22kHz AC measurement

THD+N vs. OUTPUT POWER

MAX98306 toc02

100

10

THD+N (%)

0.1

0.01

0.001

100

V

= 5V

PVDD

Z

= 8I + 68µH

MAX98306 toc01

0.750.500.25

LOAD

10

1

f = 1kHz

THD+N (%)

0.1

0.01

0.001
0 2.00

f = 6kHz

f = 100kHz

OUTPUT POWER (W)

1.751.501.251.000.750.500.25

THD+N vs. OUTPUT POWER

V

= 5V

PVDD

Z

= 4I + 33µH

LOAD

1

0 3.5

f = 6kHz

f = 1kHz

OUTPUT POWER (W)

f = 100kHz

3.02.52.01.51.00.5

MAX98306 toc03

4 ______________________________________________________________________________________

Stereo 3.7W Class D Amplifier

Typical Operating Characteristics (continued)

(V

= V

PVDD

bandwidth, TA = +25NC, unless otherwise noted.)

SHDN

= 5.0V, V

= 0V, AV = 12dB, RL = J, RL connected between OUT_+ to OUT_-, 20Hz to 22kHz AC measurement

PGND

MAX98306

100

V

= 5V

PVDD

Z

= 3I + 22µH

LOAD

10

1

THD+N (%)

0.1

0.01

0.001
0 4.03.5

f = 6kHz

f = 1kHz

OUTPUT POWER (W)

f = 100kHz

THD+N vs. FREQUENCY

10

V

= 5V

PVDD

Z

= 4I + 33µH

LOAD

1

THD+N vs. OUTPUT POWER

0.1

THD+N (%)

0.01

0.001
10 100k

2W

200mW

FREQUENCY (Hz)

10

V

= 3.7V

PVDD

Z

= 8I + 68µH

MAX98306 toc04

3.02.52.01.51.00.5

LOAD

1

0.1

THD+N (%)

0.01

0.001

700mW

200mW

10 100k

FREQUENCY (Hz)

10k1k100

MAX98306 toc05

10

1

0.1

THD+N (%)

0.01

0.001

THD+N vs. FREQUENCY

THD+N vs. FREQUENCY

MAX98306 toc07

10

1

0.1

THD+N (%)

0.01

V
Z

PVDD

LOAD

= 5V

= 3I + 22µH

2.5W

500mW

MAX98306 toc08

OUTPUT POWER (W)

2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

THD+N vs. FREQUENCY

V

= 5V

PVDD

Z

= 8I + 68µH

LOAD

1.3W

200mW

10 100k

FREQUENCY (Hz)

10k1k100

OUTPUT POWER vs. LOAD RESISTANCE

V

= 3.7V

PVDD

f = 1kHz

THD+N = 10%

THD+N = 1%

MAX98306 toc06

MAX98306 toc09

0.2

10k1k100

0.001
10 100k

FREQUENCY (Hz)

10k1k100

0

1 1000

R

LOAD

10010

(I)

OUTPUT POWER vs. LOAD RESISTANCE

4.0

3.5

3.0

2.5

2.0

1.5

OUTPUT POWER (W)

1.0

0.5

0

1 1000

THD+N = 10%

THD+N = 1%

R

(I)

LOAD

10010

_______________________________________________________________________________________ 5

V

PVDD

f = 1kHz

= 5V

MAX98306 toc10

OUTPUT POWER (W)

OUTPUT POWER vs. SUPPLY VOLTAGE

2.5
f = 1kHz
Z

= 8I + 68µH

LOAD

2.0

1.5

1.0

0.5

0

2.5 5.5

THD+N = 10%

THD+N = 1%

SUPPLY VOLTAGE (V)

OUTPUT POWER vs. SUPPLY VOLTAGE

4.0

f = 1kHz

3.5

MAX98306 toc11

3.0

2.5

2.0

1.5

OUTPUT POWER (W)

1.0

0.5

5.04.54.03.53.0

0

Z

LOAD

= 4I + 33µH

MAX98306 toc12

THD+N = 10%

THD+N = 1%

5.04.54.03.53.02.5 5.5

SUPPLY VOLTAGE (V)