MAXIM MAX98309, MAX98310 Technical data

E V A L UA T I ON K IT A V AI L A BL E

19-5912; Rev 0; 6/11

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

General Description

The MAX98309/MAX98310 mono 1.4W class AB audio amplifiers offer low quiescent current while maintaining excellent SNR and low 0.008% THD+N. These ICs feature excellent 90dB PSRR and state of the art click-andpop suppression.

The ICs are offered with an internally fixed 0dB, 3dB, 6dB, and 9dB gain (MAX98310) or an externally set gain (MAX98309) through external resistors.

The MAX98309 feature a 10ms or 100ms pin-selectable turn-on time, while the MAX98310 has a preset 5ms turnon time.

The MAX98309/MAX98310 are available in a (1.0mm x

1.0mm) 9-bump, 0.3mm pitch WLP, and are specified over the extended -40NC to +85NC temperature range.

Applications

Cell Phones/Smartphones Digital Cameras GPS Portable Media Players e-Readers Tablets

Benefits and Features

S Enhances System Performance

 Differential Input Improves Noise Immunity  Industry-Leading Click-and-Pop Suppression  High 90dB PSRR (fIN = 217Hz)

S Smaller Solution Size

 1mm x 1mm WLP Footprint

S Extends Battery Life

 Low Quiescent Current

S Delivers Robust System Design

 Thermal Overload Protection  Short-Circuit Protection

S 1.2mA Supply Current (VDD = 3.7V) S 750mW into 8I (VDD = 3.7V) S 2.5V to 5.5V Supply Operation S Pin-Selectable, Internally-Fixed Gain (MAX98310) S 1.8V Logic-Compatible SHDN Input

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part, refer to www.maxim-ic.com/MAX98309.related.

Simplified Block Diagram

BIAS V

BIAS

2.5V TO 5.5V

DD

R

V

DD

R

F

GND

F

GAIN

MAX98310

OUT+

OUT-

R

F

2.5V TO 5.5V

0.1µF 1µF

GND

R

V

DD

MAX98309

OUT+

OUT-

F

BIAS TON

BIAS

C

IN

R

IN

C

IN

R

IN

IN-

BIAS

IN+

SHDN

0.1µF 1µF

C

IN

C

IN

IN-

IN+

R

IN

R

IN

SHDN GND

�� Maxim Integrated Products 1

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.

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

ABSOLUTE MAXIMUM RATINGS

VDD to GND ............................................................... -0.3V to 6V

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

All Other Pins to GND ...............................-0.3V to (V

Continuous Current

VDD, GND, OUT_ ....................................................... Q750mA

IN_, SHDN, BIAS, GAIN, TON ......................................... Q20mA

OUT_ Short Circuit to GND or VDD Duration ............Continuous

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.

DD

+ 0.3V)

PACKAGE THERMAL CHARACTERISTICS (Note 1)

WLP

Junction-to-Ambient Thermal Resistance (BJA)......... 94°C/W

Junction-to-Case Thermal Resistance (BJC) ...............41°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.

OUT+ to OUT- Short Circuit Duration .......................Continuous

Continuous Power Dissipation (TA = +70NC)

WLP (derate 11.9mW/NC above +70NC)......................848mW

Junction Temperature .....................................................+150NC

Operating Temperature Range .......................... -40NC to +85NC

Storage Temperature Range ............................ -65NC to +150NC

Soldering Temperature (reflow).......................................+260NC

ELECTRICAL CHARACTERISTICS

(VDD = 3.7V, V TA = T

MIN to TMAX.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Supply Voltage Range V Undervoltage Lockout UVLO VDD falling 1.8 2.3 V

Quiescent Supply Current I

Shutdown Supply Current I

Turn-On Time t

Gain A

Gain Selection Threshold MAX98310

= 0V, SHDN = VDD, GAIN = VDD (0dB), C

GND

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

DD

VDD

VDD_SD

ON

Guaranteed by PSRR test 2.5 5.5 V

SHDN = V

V

SHDN

MAX98309 shutdown to full operation

MAX98310 shutdown to full operation 5.7 11.5

MAX98310

V

DD

= 0V, TA = +25NC

= 0.1µF, C

BIAS

V

= 3.7V 1.2

DD

V

= 5V 1.9 1.8

DD

TON = GND 10 22.8

TON = V

GAIN = V

GAIN = GND 2.75 3 3.25

GAIN = unconnected 5.75 6 6.25

GAIN = BIAS 8.75 9 9.25

GAIN = V

GAIN = GND

GAIN = unconnected

GAIN = BIAS

= 0.47µF, no load: RIN = RF = 10kI (MAX98309),

IN

2 3

DD

-0.25 0 +0.25

0.80 x V

DD

0.16 x V

DD

0.35 x V

DD

100

0.05 x V

DD

0.24 x V

DD

0.69 x V

DD

mA

FA

ms

dB

V

�� Maxim Integrated Products 2

Mono 1.4W Class AB Audio Amplifiers

ELECTRICAL CHARACTERISTICS (continued)

(VDD = 3.7V, V = T

MIN to TMAX.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Differential Input Resistance R

Input Bias Current I

Shutdown Input Bias Current

Output Offset Voltage

= 0V, SHDN = VDD, GAIN = VDD (0dB), C

GND

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

MAX98309, SHDN = VDD

INDIFF

INBIAS

I

INBIAS_

SHDN

V

OS

MAX98310

MAX98309/MAX98310, SHDN = V

SHDN = GND, IN_ = VDD or IN_ = GND

TA = +25NC (Note 3) Q0.2 Q1

= 0.1µF, C

BIAS

MAX98309/MAX98310

= 0.47µF, no load: RIN = RF = 10kI (MAX98309), TA

IN

1000

GAIN = 0dB 38.2 GAIN = 3dB 31.7 GAIN = 6dB 25.5

DD

-5 +5

Q1 FA

kI

FA

mV

RL = 8I, 32 samples per

Click-and-Pop Level K

Common-Mode Bias Voltage V

Input Common-Mode Voltage Range

Common-Mode Rejection Ratio CMRR MAX98310/MAX98310

Power-Supply Rejection Ratio PSRR

Output Power P

BIAS

V

OUT

CP

CM

second, A-weighted, TA = +25NC (Notes 3, 4)

Voltage at BIAS

Inferred from CMRR test 0.5

DC 2.5V to 5.5V 73 93

V

= 200mV

RIPPLE

(Note 3)

VDD = 3.7V, 1% THD+N

V

= 3.7V, 10% THD+N

DD

V

= 5V, 1% THD+N

DD

(Note 5)

VDD = 5V, 10% THD+N (Note 5)

P-P

Into shutdown -66

Out of shutdown -66

0.475 x V

Guaranteed over input commonmode voltage range

fIN = 1kHz, RL = 8I + 33FH

fIN = 217Hz 90 fIN = 1kHz 90 fIN = 10kHz 72 RL = 8I + 68FH RL = 4I + 33FH RL = 8I + 68FH RL = 4I + 33FH RL = 8I + 68FH

RL = 4I + 33FH, thermally limited

RL = 8I + 68FH

RL = 4I + 33FH, thermally limited

-50 -76

DD

0.5 x V

-62

0.750

1.2

0.9

1.5

1.4

2.1

1.7

2.7

DD

0.525

x V

DD

VDD -

0.6

dBV

V

dB

W

�� Maxim Integrated Products 3

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

ELECTRICAL CHARACTERISTICS (continued)

(VDD = 3.7V, V TA = T

MIN to TMAX.

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Total Harmonic Distortion Plus Noise

Signal-to-Noise Ratio SNR

Output Noise Voltage V

Overcurrent Protection Threshold

Thermal-Protection Threshold +160

= 0V, SH DN = VDD, GAIN = VDD (0dB), C

GND

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

fIN = 1kHz, BW = 22Hz to

THD+N

22kHz

fIN = 6kHz, BW = 22Hz to 22kHz

A-weighted, VDD = 5V, P RL = 8I + 33FH

A-weighted (Note 3) 9

N

= 0.1µF, C

BIAS

RL = 8I + 68FH, P

RL = 4I + 33FH, P

RL = 8I + 68FH, P

= 1.4W,

OUT

= 0.47µF, no load: RIN = RF = 10kI (MAX98309),

IN

= 375mW

OUT

= 750mW

OUT

= 375mW

OUT

0.06 0.02

0.008

0.01

110 dB

%

FV

2 A

NC

Thermal-Protection Hysteresis 15

Maximum Capacitive Load Drive

LOGIC INPUT (SHDN, TON) (MAX98309)

Input Logic-High V Input Logic-Low V Input Leakage Current High I Input Leakage Current Low I

Note 2: All specifications are 100% tested at TA = +25°C; temperature limits are guaranteed by design. Note 3: Inputs AC-coupled to GND. Note 4: Mode transitions controlled by SHDN. Note 5: Thermally limited by package.

C

IH

Bridge-tied load capacitance 500 pF

L

1.8V logic compliant 1.4 V

IH

1.8V logic compliant 0.4 V

IL

TA = +25NC TA = +25NC

IL

NC

1 1

FA FA

�� Maxim Integrated Products 4

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Typical Operating Characteristics

(VDD = 3.7V, V

= 0V, SHDN = VDD, GAIN = GND (RF = RIN = 10kI), C

GND

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

10

VDD = 4.2V R

= 4I

L

1

P

= 300mW

0.1

THD+N (%)

0.01

0.001

OUT

P

= 50mW

OUT

10 100k

FREQUENCY (kHz)

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

100

VDD = 3.7V

= 8I

R

L

10

1

THD+N (%)

0.1

0.01

0.001 10 100k

P

= 50mW

OUT

FREQUENCY (Hz)

TOTAL HARMONIC DISTORTION PLUS

100

10

MAX98309 toc01

10k1k100

MAX98309 toc04

P

= 500mW

OUT

10k1k100

NOISE vs. OUTPUT POWER

VDD = 3.7V R

= 4I

L

BIAS

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

100

VDD = 5V RL = 8I

10

1

P

THD+N (%)

0.1

0.01

0.001

P

= 200mW

OUT

10 100k

FREQUENCY (Hz)

OUT

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

100

VDD = 4.2V R

= 4I

L

10

1

THD+N (%)

0.001

fIN = 300Hz

0.1

0.01

0 2000

OUTPUT POWER (mW)

MAX98309 toc07

fIN = 6kHz

fIN = 1kHz

= 0.1µF, CIN = 1µF, no load, unless otherwise noted.)

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. FREQUENCY

100

VDD = 3.7V

MAX98309 toc02

= 1.2W

10k1k100

RL = 4I

10

1

P

= 800mW

THD+N (%)

0.1

0.01

0.001 10 100k

OUT

P

= 50mW

OUT

FREQUENCY (Hz)

10k1k100

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

100

VDD = 5V R

= 8I

MAX98309 toc05

THD+N (%)

0.001

15001000500

L

10

1

0.1

0.01

fIN = 300Hz

0 1750

OUTPUT POWER (mW)

fIN = 6kHz

fIN = 1kHz

150012501000750500250

TOTAL HARMONIC DISTORTION PLUS

NOISE vs. OUTPUT POWER

100

VDD = 3.7V RL = 8I

10

MAX98309 toc08

MAX98309 toc03

MAX98309 toc06

1

fIN = 300Hz

THD+N (%)

0.1

0.01

0.001 0 1600

fIN = 6kHz

fIN = 1kHz

OUTPUT POWER (mW)

1200800400

1

THD+N (%)

0.1

0.01

0.001

fIN = 300Hz

0 1000

fIN = 6kHz

fIN = 1kHz

OUTPUT POWER (mW)

800600400200

�� Maxim Integrated Products 5

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Typical Operating Characteristics (continued)

(VDD = 3.7V, V

= 0V, SHDN = VDD, GAIN = GND (RF = RIN = 10kI), C

GND

OFFSET VOLTAGE

vs. COMMON-MODE VOLTAGE

5

4

3

2

1

(mV)

0

OS

V

-1

-2

-3

-4

-5 0 5

COMMON-MODE VOLTAGE (V)

VDD = 5V

RL = 8

4321

I

MAX98309 toc09

OUTPUT POWER vs. SUPPLY VOLTAGE

2500

fIN = 1kHz RL = 8I

2000

1500

1000

OUTPUT POWER (mW)

500

THD+N = 10%

MAX98309 toc11

= 0.1µF, CIN = 1µF, no load, unless otherwise noted.)

BIAS

OFFSET VOLTAGE

vs. COMMON-MODE VOLTAGE

4

3

2

1

(mV)

0

OS

V

-1

-2

-3

-4 0 3.5

COMMON-MODE VOLTAGE (V)

VDD = 3.7V

RL = 8I

3.02.50.5 1.0 1.5 2.0

MAX98309 toc10

OUTPUT POWER vs. SUPPLY VOLTAGE

3500

fIN = 1kHz

= 4I

R

500

L

THD+N = 10%

MAX98309 toc12

THERMALLY

LIMITED

THD+N = 1%

3000

2500

2000

1500

OUTPUT POWER (mW)

1000

0

2.5 5.5 SUPPLY VOLATGE (V)

OUTPUT POWER vs. LOAD

3.0

2.5

2.0

1.5

1.0

OUTPUT POWER (W)

0.5

0

LOAD RESISTANCE (I)

Z

LOAD

THERMALLY LIMITED

THD+N = 10%

THD+N = 1%

100101 1k

5.04.54.03.53.0

VDD = 5V

= 1kHz

f

IN

= LOAD + 68µH

MAX98309 toc13

0

2.5 5.5 SUPPLY VOLATGE (V)

OUTPUT POWER vs. LOAD

1.8

1.6

1.4

1.2

1.0

0.8

0.6

OUTPUT POWER (mW)

0.4

THD+N = 1%

0.2

0

1 1k

LOAD RESISTANCE (I)

Z

LOAD

THD+N = 10%

= LOAD + 68µH

10010

5.04.54.03.53.0

VDD = 3.7V

= 1kHz

f

IN

�� Maxim Integrated Products 6

MAX98309 toc14

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Typical Operating Characteristics (continued)

(VDD = 3.7V, V

= 0V, SHDN = VDD, GAIN = GND (RF = RIN = 10kI), C

GND

POWER DISSIPATION

vs. OUTPUT POWER

1400

1200

1000

800

600

400

POWER DISSIPATION (mW)

200

0

0 2000

RL = 4I

OUTPUT POWER (mW)

0

RL = 8I

-10 V

RIPPLE

-20

-30

-40

-50

-60

-70

PSRR (dB)

-80

-90

-100

-110

-120

-130

-140 10 100k

0

RL = 8I

-10 THD + N = 1%

-20

-30

-40

-50

CMRR (dB)

-60

-70

-80

-90

-100 10 100k

VDD = 5V

= 1kHz

f

= P

RL = 8I

OUTL

15001000500

IN

+ P

OUTR

P

OUT

PSRR vs. FREQUENCY

(MAX98309)

= 200mV

VDD = 5V

VDD = 3.7V

FREQUENCY (Hz)

CMRR vs. FREQUENCY

(MAX98309)

VDD = 3.7V

VDD = 5V

FREQUENCY (Hz)

800

700

MAX98309 toc15

600

500

400

300

POWER DISSIPATION (mW)

200

100

0

0 1500

10k1k100

POWER DISSIPATION

vs. OUTPUT POWER

RL = 8I

OUTPUT POWER (mW)

MAX98309 toc18

MAX98309 toc20

RL = 4I

P

OUT

= 0.1µF, CIN = 1µF, no load, unless otherwise noted.)

BIAS

GAIN vs. FREQUENCY

(MAX98310)

12 11

= P

VDD = 3.7V

fIN = 1kHz

OUTL

1200900300 600

+ P

OUTR

MAX98309 toc16

10

9 8 7 6 5 4 3

GAIN (dB)

2 1 0

-1

-2

-3

-4

-5 10 100k 1000k

AV = 9dB

AV = 6dB

AV = 3dB

AV = 0dB

10k1k100

FREQUENCY (Hz)

PSRR vs. FREQUENCY

(MAX98310)

0

RL = 8I

-10 V

= 200mV

RIPPLE

-20

-30

-40

-50

-60

PSRR (dB)

-70

-80

-90

-100

-110

-120 10 100k

VDD = 3.7V

VDD = 5V

10k1k100

FREQUENCY (Hz)

CMRR vs. FREQUENCY

(MAX98310)

0

RL = 8I

-10 THD + N = 1%

-20

-30

-40

-50

CMRR (dB)

-60

-70

-80

-90

-100 10 100k

VDD = 3.7V

VDD = 5V

10k1k100

FREQUENCY (Hz)

MAX98309 toc17

MAX98309 toc19

MAX98309 toc21

�� Maxim Integrated Products 7

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Typical Operating Characteristics (continued)

(VDD = 3.7V, V

= 0V, SHDN = VDD, GAIN = GND (RF = RIN = 10kI), C

GND

TURN-ON TIME (MAX98309) 10ms

2ms/div

3.0

2.5

2.0

1.5

1.0

SUPPLY CURRENT (mA)

0.5

MAX98309 toc22

SUPPLY CURRENT

vs. SUPPLY VOLTAGE

= 0.1µF, CIN = 1µF, no load, unless otherwise noted.)

BIAS

TURN-ON TIME (MAX98309) 100ms

20ms/div

MAX98309 toc25

MAX98309 toc23

TURN-ON TIME MAX98310

SUPPLY CURRENT vs. TEMPERATURE

2.5

2.0

1.5

1.0

SUPPLY CURRENT (mA)

0.5

VDD = 5V

VDD = 3.7V

MAX98309 toc24

1ms/div

MAX98309 toc26

0

2.5 5.5 SUPPLY VOLTAGE (V)

SHUTDOWN CURRENT vs. SUPPLY VOLTAGE

9

8

7

6

5

4

3

SHUTDOWN CURRENT (µA)

2

1

0

2.5 5.5 SUPPLY VOLTAGE (V)

5.04.54.03.53.0

MAX98309 toc27

5.04.54.03.53.0

0

-40 85 TEMPERATURE (°C)

SHUTDOWN CURRENT

vs. TEMPERATURE

10

9

8

7

6

5

4

3

SHUTDOWN CURRENT (µA)

2

1

0

-40 85

VDD = 5V

VDD = 3.7V

TEMPERATURE (°C)

603510-15

MAX98309 toc28

603510-15

�� Maxim Integrated Products 8

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Pin Configurations

TOP VIEW

(BUMP SIDE DOWN)

A

B

C

MAX98309

1

+

OUT+ SHDN

GND

OUT- BIAS

2 3

TON V

IN-

DD

IN+

TOP VIEW

(BUMP SIDE DOWN)

A

B

C

WLP

MAX98309 MAX98310

NAME FUNCTION

A1 A1 OUT+ Amplifier Positive Output

A2 A2

SHDN

Active-Low Shutdown Input. Connect to GND to place the IC into shutdown. Connect to VDD for normal operation.

A3 A3 IN- Inverting Audio Input B1 B1 GND Ground

B2 — TON

Turn-On Time Selection. Connect TON to GND for a 10ms turn-on time. Connect TON to VDD for a 100ms turn on time.

— B2 GAIN Gain Select Input. See Table 1 for gain settings.

B3 B3 V

DD

Power Supply Input. Connect a 1FF capacitor from VDD to GND. C1 C1 OUT- Amplifier Negative Output C2 C2 BIAS

Common-Mode DC Bias Bypass. Connect a 0.1FF (min) capacitor to GND. C3 C3 IN+ Noninverting Audio Input

MAX98310

1

+

OUT+ SHDN

GND

OUT- BIAS

2 3

GAIN V

WLP

IN-

DD

IN+

Pin Descriptions

�� Maxim Integrated Products 9

MAX98309/MAX98310

V

Mono 1.4W Class AB Audio Amplifiers

Detailed Description

The MAX98309/MAX98310 mono 1.4W Class AB audio amplifiers offer low quiescent current while maintaining excellent SNR and low 0.008% THD+N. Both ICs feature excellent 90dB PSRR and state-of-the-art click-and-pop suppression.

The ICs are offered with an internally fixed 0dB, 3dB, 6dB, and 9dB gain (MAX98310) or an externally set gain (MAX98309) through external resistors.

The MAX98309 features a 10ms or 100ms pin-selectable turn-on time, while the MAX98310 has a preset 5ms turnon time.

Bias

The ICs operate from a single 2.5V to 5.5V power supply and feature an internally generated common-mode bias voltage of VDD/2 reference to ground. BIAS provides both click-and-pop suppression and sets the DC bias level for the audio outputs. Choose the value of the bypass capacitor as described in the BIAS Capacitor section. Do not connect external loads to BIAS as this can affect the overall performance.

Turn-On Time

The MAX98309 external gain amplifier features a selectable turn-on time for optimized click-and-pop performance. Connect TON to GND for a 10ms turn-on time. Connect TON to VDD for a 100ms turn-on time. The MAX98310 has a preset 5ms turn-on time.

Shutdown Mode

The ICs feature a 1.8FA low-power shutdown mode that reduces quiescent current consumption. When the active-low shutdown mode is entered, the ICs’ internal bias circuitry is disabled, the amplifier outputs go high impedance, and BIAS is driven to GND.

Click-and-Pop Suppression

The ICs feature Maxim’s industry-leading click-andpop suppression circuitry. During startup, the amplifier common-mode bias voltage ramps to the DC bias point. When entering shutdown, the amplifier outputs are high impedance between both outputs. This scheme minimizes the energy present in the audio band.

Applications Information

BTL Amplifier

The ICs are designed to drive a load differentially, a configuration referred to as bridge-tied load, or BTL. The BTL configuration (Figure 1) offers advantages over the single-ended configuration, where one side of the load is connected to ground. Driving the load differentially doubles the output voltage compared to a single-ended amplifier under similar conditions.

Substituting 2 x V

OUT(P-P)

equations yields four times the output power due to doubling of the output voltage:

P

Because the differential outputs are biased at midsupply, there is no net DC voltage across the load. This eliminates the need for DC-blocking capacitors required for single-ended amplifiers. These capacitors can be large, expensive, consume board space, and degrade lowfrequency performance.

Power Dissipation and Heatsinking

Under normal operating conditions, the ICs dissipate a significant amount of power. The maximum power dissipation is given in the Absolute Maximum Ratings or can be calculated by the following equation:

D(MAX)

where T

is +150NC, TA is the ambient temperature,

J(MAX)

and BJA is the reciprocal of the derating factor in C/W as specified in the Absolute Maximum Ratings.

V

RMS

OUT

for V

=

+1

-1

OUT(P-P)

OUT (P P)

−

2 2

V 2

RMS

R

L

T TP−

J(MAX) A

θ

JA

into the following

V

OUT(P-P)

2 x V

OUT(P-P)

V

OUT(P-P)

Figure 1. BTL Configuration

�� Maxim Integrated Products 10

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

The increase in power delivered by the BTL configuration directly results in an increase in internal power dissipation over the single-ended configuration. The maximum internal power dissipation for a given VDD and load is given by the following equation:

2

2V

P

D(MAX)

DD

2

R=π

L

If the internal power dissipation for a given application exceeds the maximum allowed for a given package, reduce power dissipation by increasing the ground plane heatsinking capability and the size of the traces to the device. See the Layout and Grounding section. Other methods for reducing power dissipation are to reduce VDD, increase load impedance, decrease ambient temperature, reduce gain, or reduce input signal.

Thermal-overload protection limits total power dissipation in the MAX98309/MAX98310. When the junction temperature exceeds +160NC, the thermal protection circuitry disables the amplifier. Operation returns to normal once the die cools by 15NC.

Amplifier Gain

Fixed Differential Gain (MAX98310)

The MAX98310 features four internally fixed differential gain options selectable by GAIN (Table 1). This simplifies design, decreases required application footprint size, and eliminates external gain-setting resistors.

External Differential Gain (MAX98309)

The MAX98309 features an external gain option. Resistors RF and RIN. See the Simplified Block Diagram and set the gain of the amplifier as follows:

R

AR=

F

V

IN

where AV is the desired voltage gain. Hence, an RIN of 10kI and an RF of 20kI yields a gain of 2V/V or 6dB. RF can be either fixed or variable, allowing the use of a digitally controlled potentiometer to alter the gain under software control.

Table 1. Fixed Differential Gain

GAIN CONNECTION GAIN (dB)

V

DD

GND 3

Unconnected 6

BIAS 9

0

Input Filter

The fully differential amplifier inputs can be biased at voltages other than midsupply. The common-mode feedback circuit adjusts for input bias, ensuring the outputs are still biased at midsupply. Input capacitors are not required as long as the input voltage is within the specified common-mode range listed in the Electrical

Characteristics table.

If input capacitors are used, input capacitor CIN, in conjunction with the input resistor RIN, forms a highpass filter that removes the DC bias from an incoming signal. The AC-coupling capacitor allows the amplifier to bias the signal to an optimum DC level. Assuming zero-source impedance, the -3dB point of the highpass filter is given by:

=

2 R C

π

1

IN IN

Setting f

f

3dB

−

too high affects the low-frequency response

-3dB

of the amplifier. Use capacitors with adequately low voltage coefficients, such as X7R ceramic capacitors with a high voltage rating. Capacitors with higher voltage coefficients result in increased distortion at low frequencies.

BIAS Capacitor

BIAS is the output of the internally generated VDD/2 bias voltage. The BIAS bypass capacitor, C

, improves

BIAS

PSRR and THD+N by reducing power supply and other noise sources at the common-mode bias node, and also generates the clickless/popless startup DC bias waveform for the speaker amplifiers. Bypass BIAS with a 0.1FF capacitor to GND. Larger values of C

(up to 1FF)

BIAS

improve PSRR.

Supply Bypassing

Proper power-supply bypassing ensures low-noise, lowdistortion performance. Connect a 1FF ceramic capacitor from VDD to GND. Add additional bulk capacitance as required by the application. Locate the bypass capacitor as close as possible to the device.

Layout and Grounding

Good PCB layout is essential for optimizing performance. Use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace resistance and route heat away from the device. Good grounding improves audio performance, and prevents any digital switching noise from coupling into the audio signal.

�� Maxim Integrated Products 11

Mono 1.4W Class AB Audio Amplifiers

PART TEMP RANGE GAIN PIN-PACKAGE TOP MARK

MAX98309EWL+ MAX98310EWL+

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

-40NC to +85NC

MAX98309/MAX98310

Ordering Information

External 9 WLP +AIY

Fixed 9 WLP +AIZ

�� Maxim Integrated Products 12

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Package Information

For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status.

PACKAGE TYPE PACKAGE CODE OUTLINE NO. LAND PATTERN NO.

9 WLP (0.3mm pitch) W91D1+1

PIN 1 INDICATOR

E

1

A

AAAA

TOP VIEW

MARKING

D

0.05

S

A1

S

21-0486

SIDE VIEW

See Note 7

Refer to Application Note 1891

COMMON DIMENSIONS

0.64

A

A3

A2

A

A1

A2

A3

b

D1

E1

e

SD

SE

0.05

0.16

0.03

0.48

REF

0.025

BASIC

0.21

0.03

0.60

BASIC

0.60

BASIC

0.30

BASIC

0.00 BASIC

B

C

B

A

1 2 3

A

BOTTOM VIEW

-DRAWING NOT TO SCALE-

E

MAX

PKG. CODE

W91D1+1

E1

e

SE

SD

D1

b

NOTES:

1. Terminal pitch is defined by terminal center to center value.

2. Outer dimension is defined by center lines between scribe lines.

3. All dimensions in millimeter.

4. Marking shown is for package orientation reference only.

5. Tolerance is ± 0.02 unless specified otherwise.

6. All dimensions apply to PbFree (+) package codes only.

7. Front - side finish can be either Black or Clear.

MIN

0.95 0.98 0.95 0.98

TITLE

APPROVAL

PACKAGE OUTLINE 9 BUMPS, WLP PKG. 0.3mm PITCH

DOCUMENT CONTROL NO.

MIN

D

MAX

21-0486

DEPOPULATED BUMPS

NONE

REV.

1

B

�� Maxim Integrated Products 13

MAX98309/MAX98310

Mono 1.4W Class AB Audio Amplifiers

Revision History

REVISION

NUMBER

0 6/11 Initial release —

REVISION

DATE

DESCRIPTION

PAGES

CHANGED

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. The parametric values (min and max limits) shown in the Electrical Characteristics table are guaranteed. Other parametric values quoted in this data sheet are provided for guidance.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 14

©

2011 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.

MAXIM MAX98309, MAX98310 Technical data

Specifications and Main Features

Frequently Asked Questions

User Manual

General Description

Applications

Benefits and Features

Simplified Block Diagram

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

Typical Operating Characteristics

Pin Configurations

Pin Descriptions

Detailed Description

Bias

Turn-On Time

Shutdown Mode

Click-and-Pop Suppression

Applications Information

BTL Amplifier

Power Dissipation and Heatsinking

Figure 1. BTL Configuration

Amplifier Gain

Fixed Differential Gain (MAX98310)

External Differential Gain (MAX98309)

Table 1. Fixed Differential Gain

Input Filter

BIAS Capacitor

Supply Bypassing

Layout and Grounding

Ordering Information

Package Information

Revision History