Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsLinear ICsLinear IC - Audio amplifier 2-channel (stereo) Class D TQFN 16 (5x5)

General Description

The MAX9715 high-efficiency, stereo, Class D audio

power amplifier provides up to 2.8W per channel into a

4Ω speaker with a 5V supply. Maxim’s second-generation

Class D technology features robust output protection,

high efficiency, and high power-supply rejection (PSRR)

while eliminating the need for output filters. Selectable

gain settings, +10.5dB or +9.0dB, adjust the amplifier

gain to suit the audio input level and speaker load.

The MAX9715 features high PSRR (71dB at 1kHz),

allowing for operation from noisy supplies without addi-

tional regulation. Comprehensive click-and-pop sup-

pression eliminates audible clicks and pops at startup

and shutdown. The MAX9715 operates from a single 5V

supply and consumes only 12mA of supply current.

Integrated shutdown control reduces supply current to

less than 100nA.

The MAX9715 is fully specified over the extended

-40°C to +85°C temperature range and is available in a

thermally enhanced 16-pin TQFN-EP package.

Applications

High-End Notebook Audio

LCD Projectors

Portable Audio

Multimedia Docking Stations

Features

♦ 5V Single-Supply Operation

♦ Spread-Spectrum Modulator Reduces EMI

♦ 2.8W, Class D, Stereo Speaker Amplifier (4Ω)

♦ Filterless Class D Requires No LC Output Filter

♦ High PSRR (71dB at 1kHz)

♦ 86% Efficiency (R

= 8Ω, P

OUT

= 1W)

♦ Low-Power Shutdown Mode

♦ Integrated Click-and-Pop Suppression

♦ Low Total Harmonic Distortion: 0.06% at 1kHz

♦ Short-Circuit and Thermal Protection

♦ Internal Gain, +9.0dB or +10.5dB

♦ Available in Space-Saving Package

16-Pin Thin QFN-EP (5mm x 5mm x 0.8mm)

MAX9715

2.8W, Low-EMI, Stereo, Filterless

Class D Audio Amplifier

________________________________________________________________

Maxim Integrated Products

1234

12 11 10 9

INL

INR

BIAS

PGND

OUTR+

OUTR-

OUTL+

OUTL-

N.C.

GAIN

GND

PGND

SHDN

TOP VIEW

MAX9715

TQFN

Pin Configurations

Ordering Information

MAX9715

OUTR+

OUTR-

OUTL+

OUTL-

CLASS D

AMPLIFIER

INR

GAIN

INL

4.5V TO 5.5V SUPPLY

Block Diagram

19-3589; Rev 2; 7/08

Denotes a lead-free/RoHS-compliant package.

EP = Exposed pad.

PART TEMP RANGE PIN-PACKAGE

MAX9715ETE+ -40°C to +85°C 16 TQFN-EP*

Typical Operating Circuit/Functional Diagram appears at

end of data sheet.

EVALUATION KIT

AVAILABLE

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.

Summary of content (13 pages)

PAGE 1
9-3589; Rev 2; 7/08 KIT ATION EVALU E L B AVAILA 2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier The MAX9715 high-efficiency, stereo, Class D audio power amplifier provides up to 2.8W per channel into a 4Ω speaker with a 5V supply. Maxim’s second-generation Class D technology features robust output protection, high efficiency, and high power-supply rejection (PSRR) while eliminating the need for output filters. Selectable gain settings, +10.5dB or +9.
PAGE 2
MAX9715 2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier ABSOLUTE MAXIMUM RATINGS VDD, PVDD, to GND ...............................................................+6V GND to PGND .......................................................-0.3V to +0.3V Any Other Pin to PGND ............................. -0.3V to (VDD + 0.3V) Duration of OUT__ Short Circuit to PGND or PVDD ....Continuous Duration of OUT_+ Short Circuit between OUT_- ......Continuous Continuous Current Into/Out of (PVDD, OUT__, PGND)...
PAGE 3
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier (VDD = PVDD = 5.0V, GND = PGND = 0V, VSHDN = VDD, CBIAS = 1μF, speaker impedance = 8Ω in series with 68μH connected between OUT_+ and OUT_-, GAIN = +10.5dB, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.
PAGE 4
Typical Operating Characteristics (continued) (VDD = 5.0V, CVDD = 3 x 0.1μF, CBIAS = 1μF, CINL = CINR = 1μF, AV = +10.5dB, TA = +25°C, unless otherwise noted.) (See the Typical Operating Circuit/Functional Diagram) EFFICIENCY vs. OUTPUT POWER TOTAL HARMONIC DISTORTION PLUS NOISE vs. OUTPUT POWER 0.1 fIN = 10kHz 80 60 50 40 VDD = 5V fIN = 1kHz POUT = POUTL + POUTR OUTPUTS IN-PHASE 20 VDD = 5V RL = 8Ω 10 0 0.001 0 0 OUTPUT POWER (W) 4 2 3 OUTPUT POWER (W) EFFICIENCY vs.
PAGE 5
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier -40 -50 -60 -70 -80 -40 -60 RIGHT TO LEFT -80 LEFT TO RIGHT MAX9715toc12 -60 -70 -80 -90 -100 -110 -120 -100 -90 -130 -120 -100 0.1 1 10 100 -140 0.01 0.1 1 10 100 5 10 15 FREQUENCY (kHz) FREQUENCY (kHz) OUTPUT SPECTRUM vs. FREQUENCY (A-WEIGHTED) WIDEBAND SPECTRUM SUPPLY CURRENT vs.
PAGE 6
Typical Operating Characteristics (continued) (VDD = 5.0V, CVDD = 3 x 0.1μF, CBIAS = 1μF, CINL = CINR = 1μF, AV = +10.5dB, TA = +25°C, unless otherwise noted.) (See the Typical Operating Circuit/Functional Diagram) SHUTDOWN CURRENT vs. SUPPLY VOLTAGE POWER-ON/OFF WAVEFORM MAX9715 toc17 MAX9715 toc16 0.40 0.35 SHUTDOWN CURRENT (μA) MAX9715 2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier SHDN 5V/div 0.30 0.25 0.20 0.15 IOUT 200mA/div 0.10 0.05 0 4.8 4.5 5.0 5.3 5.
PAGE 7
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier MAX9715 fig01 45 AMPLITUDE (dBμV/m) MAX9715 50 40 35 30 25 20 15 30 60 80 100 120 140 160 180 200 220 240 260 280 300 FREQUENCY (MHz) Figure 1. MAX9715 Radiated Emissions with 75mm of Speaker Cable Detailed Description The MAX9715 2.8W, Class D speaker amplifier with gain control offers Class AB performance with Class D efficiency while occupying minimal board space.
PAGE 8
Efficiency Efficiency of a Class D amplifier is attributed to the region of operation of the output-stage transistors. In a Class D amplifier, the output transistors act as current-steering switches and consume negligible additional power. Any power loss associated with the Class D output stage is mostly due to the I2R loss of the MOSFET on-resistance, switching losses, and quiescent current overhead. EFFICIENCY vs.
PAGE 9
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier Component Selection Input Filter The input capacitor (CIN), in conjunction with the amplifier input resistance (R IN ), forms a highpass filter that removes the DC bias from an incoming signal (see the Typical Application Circuit). The AC-coupling capacitor allows the amplifier to bias the signal to an optimum DC level.
PAGE 10
MAX9715 2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier Supply Bypassing, Layout, and Grounding Proper layout and grounding are essential for optimum performance. Use large traces for the power-supply inputs and amplifier outputs to minimize losses due to parasitic trace resistance. Large traces also aid in moving heat away from the package. Proper grounding improves audio performance, minimizes crosstalk between channels, and prevents any switching noise from coupling into the audio signal.
PAGE 11
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier 5V 22μF C1 15nF LEFT IN 8Ω 22μF MAX9715 C2 15nF RIGHT IN 8Ω R3 7.5kΩ C5 1μF C4 2.2nF R1 15kΩ R4 15kΩ C6 1μF R2 15kΩ 12V 1μF C3 22nF 2.
PAGE 12
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier MAX9715 Typical Operating Circuit/Functional Diagram 4.5V TO 5.5V SHUTDOWN CONTROL * 0.1μF 0.1μF VDD 0.
PAGE 13
2.8W, Low-EMI, Stereo, Filterless Class D Audio Amplifier REVISION NUMBER REVISION DATE 2 7/08 DESCRIPTION Removed TSSOP package option PAGES CHANGED 1, 2, 6, 12 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.