Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) Class D WLP 16 (2x2)

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MAX98500

Boosted 2.2W Class D Amplifier

with Automatic Level Control

19-5189; Rev 0; 5/10

Simplified Block Diagram

General Description

The MAX98500 is a high-efficiency, Class D audio ampli-

fier that features an integrated boost converter to deliver

a constant output power over a wide range of battery

supply voltages.

The boost converter operates at 2MHz, requiring only a

small (2.2FH) external inductor and capacitor.

The automatic level control has a battery tracking func-

tion that reduces the output swing as the supply voltage

drops, preventing collapse of battery voltage.

The amplifier has differential inputs and an internal fully

differential design. The MAX98500 also features three

gain settings (6dB, 15.5dB, and 20dB) that are select-

able with a logic input.

The MAX98500 is available in a small, 0.5mm pitch

16-bump WLP package (2.1mm x 2.1mm). It is specified

over the extended -40NC to +85NC temperature range.

Applications

Cell Phones

Smartphones

GPS Devices

Mobile Internet Devices

Active Speaker Accessories

Features

S Boosted Class D Output

Integrated Automatic Level Control

Output Power

2.2W into 8I, 10% THD+N

1.7W into 8I, 1% THD+N

Wide 2.5V to 5.5V Supply Voltage Range

Undervoltage Lockout Protection

High Total Efficiency of 87%

High Step-Up Switching Frequency (2MHz)

Active Emission Limiting for Low EMI

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

Ordering Information

Typical Application Circuit appears at end of data sheet.

PART TEMP RANGE PIN-PACKAGE

MAX98500EWE+

-40NC to +85NC

16 WLP

CONTROL

DIFFERENTIAL

INPUT

BOOST CONVERTER

GAIN

OUTPUT

STAGE

BATTERY

SPKP

SPKN

PVDD

CCOUT

LXV

BAT

AGND SPKPGNDBSTPGND

C4 A4 D1, C2

RKNEE B3

GAIN

SDSPK

SDBST

B4 A3

INP D2

INN

MAX98500

Summary of content (15 pages)

PAGE 1
9-5189; Rev 0; 5/10 Boosted 2.2W Class D Amplifier with Automatic Level Control Features The MAX98500 is a high-efficiency, Class D audio amplifier that features an integrated boost converter to deliver a constant output power over a wide range of battery supply voltages. S Boosted Class D Output S Integrated Automatic Level Control S Output Power 2.2W into 8I, 10% THD+N 1.7W into 8I, 1% THD+N The boost converter operates at 2MHz, requiring only a small (2.2FH) external inductor and capacitor.
PAGE 2
MAX98500 Boosted 2.2W Class D Amplifier with Automatic Level Control ABSOLUTE MAXIMUM RATINGS Duration of SPK_ Short Circuit to PVDD or SPKPGND...............................................................Continuous Duration of Short Circuit Between SPKP and SPKN...............................................................Continuous Continuous Power Dissipation, Multilayer Board (TA = +70NC) WLP (derate 20.4mW/NC above +70NC)........................1.33W θJA (Note 1).....................................
PAGE 3
Boosted 2.2W Class D Amplifier with Automatic Level Control (VBAT = 3.6V, RL = J between SPKP and SPKN, AV = +6dB, CIN = 1FF, 20Hz to 22kHz AC measurement bandwidth, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.
PAGE 4
MAX98500 Boosted 2.2W Class D Amplifier with Automatic Level Control ELECTRICAL CHARACTERISTICS (continued) (VBAT = 3.6V, RL = J between SPKP and SPKN, AV = +6dB, CIN = 1FF, 20Hz to 22kHz AC measurement bandwidth, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2) PARAMETER Knee Resistor SYMBOL RKNEE DIGITAL INPUTS (SDBST, SDSPK) Input Voltage High ViH Input Voltage Low VIL Input Capacitance CIN Input Leakage Current IIN CONDITIONS TA = +25NC, AV = 15.
PAGE 5
Boosted 2.2W Class D Amplifier with Automatic Level Control General BATTERY CURRENT vs. BATTERY VOLTAGE INPUTS AC-COUPLED TO AGND SDSPK = GND, SDBST = VBAT BATTERY CURRENT (µA) BATTERY CURRENT (mA) 4.0 140 MAX98500 toc02 INPUTS AC-COUPLED TO AGND SDSPK = SDBST = VBAT 4.5 MAX98500 toc01 5.0 BATTERY CURRENT vs. BATTERY VOLTAGE 3.5 3.0 2.5 2.0 1.5 1.0 120 100 80 0.5 60 0 2.5 3.0 3.5 4.0 4.5 5.0 3.5 4.0 4.5 BATTERY VOLTAGE (V) BATTERY VOLTAGE (V) BATTERY CURRENT vs.
PAGE 6
Typical Operating Characteristics (continued) (VBAT = 3.6V, RL = ∞ between SPKP and SPKN, AV = +15.5dB, RKNEE = VBAT, 20Hz to 22kHz AC measurement bandwidth, unless otherwise noted.) Speaker MAX98500 toc06 ZLOAD = 8I + 68µH 1 ZLOAD = 8I + 68µH 10 POUT = 1.4W THD+N (%) THD+N (%) 100 MAX98500 toc07 THD+N vs. OUTPUT POWER THD+N vs. FREQUENCY 10 0.1 1 f = 6kHz 0.1 f = 1kHz POUT = 400mW 0.01 0.01 f = 100Hz 0.001 0.001 0.1 1 10 100 0 0.4 OUTPUT POWER vs.
PAGE 7
Boosted 2.2W Class D Amplifier with Automatic Level Control SPEAKER POWER-SUPPLY REJECTION RATIO vs. FREQUENCY -20 MAX98500 toc12 VRIPPLE AT PVDD = 200mVP-P INPUTS AC-COUPLED AGND SHUTDOWN RESPONSE MAX98500 toc13 0 MAX98500 toc11 0 COMMON-MODE REJECTION RATIO vs. FREQUENCY ZLOAD = 8I + 68µH -20 SDSPK 2V/div -40 CMRR (dB) -60 0V AV = 6dB -60 -80 -80 -100 -100 SPKR OUTPUT 1V/div 0V AV = 20dB 0.1 1 10 100 0.1 0.
PAGE 8
Typical Operating Characteristics (continued) (VBAT = 3.6V, RL = ∞ between SPKP and SPKN, AV = +15.5dB, RKNEE = VBAT, 20Hz to 22kHz AC measurement bandwidth, unless otherwise noted.) Boost Converter EFFICIENCY vs. OUTPUT CURRENT 0 94 92 VBAT = 4V 90 88 VBAT = 3.6V 86 VBAT = 3V 84 82 VBAT = 5V -0.2 VBAT = 4.2V -0.4 VBAT = 4V -0.6 -0.8 VBAT = 3.6V -1.0 VBAT = 3.3V 80 -1.2 0 MAX98500 toc19 VBAT = 5V 200 400 600 800 1000 1200 1400 1600 0 VBAT = 3.
PAGE 9
Boosted 2.2W Class D Amplifier with Automatic Level Control TOP VIEW (BUMP SIDE DOWN) MAX98500 1 2 3 4 A PVDD VCCOUT LX BSTPGND B SPKP GAIN RKNEE VBAT C SPKN SPKPGND SDSPK AGND D SPKPGND INP INN SDBST + WLP Pin Description BUMP NAME A1 PVDD A2 VCCOUT FUNCTION Speaker Amplifier Power Supply. Bypass to SPKPGND with a 0.1mF capacitor. Boost Converter Output. Connect a 22mF (0805) capacitor between VCCOUT and BSTPGND.
PAGE 10
Detailed Description The MAX98500 is a high-efficiency Class D audio amplifier that features an integrated boost converter to deliver a constant output power over a large range of battery supply voltages. The boost converter operates at 2MHz, requiring only a small (2.2FH) external inductor and output capacitor. The amplifier has differential inputs and an internal fully differential design with three gain settings (6dB, 15.5dB, and 20dB) that are selectable with a logic input.
PAGE 11
Boosted 2.2W Class D Amplifier with Automatic Level Control SDSPK BOOST STATUS SPEAKER STATUS Low Low Off Off Low High Off Off High Low On Off High High On On SDBST Shutdown The MAX98500 features two active-low shutdown inputs (SDSPK and SDBST). Table 2 shows the different shutdown configurations. Click-and-Pop Suppression threshold, the soft-start begins. When the input voltage falls below the UVLO threshold, the boost converter and speaker amplifier turn off.
PAGE 12
MAX98500 Boosted 2.2W Class D Amplifier with Automatic Level Control Route audio signals on the middle layers of the PCB to allow the ground planes above and below to shield them from RF interference. Ideally the top and bottom layers of the PCB should primarily be ground planes to create effective shielding. Additional RF immunity can also be obtained from relying on the self-resonant frequency of capacitors as it exhibits the frequency response similar to a notch filter.
PAGE 13
Boosted 2.2W Class D Amplifier with Automatic Level Control Bypass VBAT with a 10FF capacitor and a system bulk capacitance of 22FF or larger. Bypass PVDD to SPKPGND with a 0.1FF capacitor and with as minimal a loop area as possible. Connect SPKP and SPKN to the speaker using the shortest and widest traces possible. Reducing trace length minimizes radiated EMI. Route SPKP/SPKN as a differential pair on the PCB to minimize loop area, thereby, the inductance of the circuit.
PAGE 14
MAX98500 Boosted 2.2W Class D Amplifier with Automatic Level Control Package Information For the latest package outline information and land patterns, 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 Document No.
PAGE 15
Boosted 2.2W Class D Amplifier with Automatic Level Control REVISION NUMBER REVISION DATE 0 5/10 DESCRIPTION Initial release 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.