Filterless, High Efficiency, Mono 3 W Class-D Audio Amplifier SSM2315 The SSM2315 features a high efficiency, low noise modulation FEATURES scheme that requires no external LC output filters. The modulation Filterless Class-D amplifier with - modulation continues to provide high efficiency even at low output power. No sync necessary when using multiple Class-D amplifiers It operates with 93% efficiency at 1.4 W into 8 or 85% efficiency from Analog Devices, Inc. at 3 W into 3 from a 5.0 V supply and has an SNR of >103 dB. 3 W into 3 load and 1.4 W into 8 load at 5.0 V supply Spread-spectrum pulse density modulation is used to provide with <1% total harmonic distortion (THD + N) 93% efficiency at 5.0 V, 1.4 W into 8 speaker lower EMI-radiated emissions compared with other Class-D >103 dB signal-to-noise ratio (SNR) architectures. Single-supply operation from 2.5 V to 5.5 V The SSM2315 has a micropower shutdown mode with a typical 20 nA ultralow shutdown current shutdown current of 20 nA. Shutdown is enabled by applying Short-circuit and thermal protection SD a logic low to the pin. Available in 9-ball, 1.5 mm 1.5 mm WLCSP Pop-and-click suppression The device also includes pop-and-click suppression circuitry. Built-in resistors reduce board component count This suppression circuitry minimizes voltage glitches at the Default fixed 6 dB or user adjustable gain setting output during turn-on and turn-off, reducing audible noise on activation and deactivation. APPLICATIONS Mobile phones The fully differential input of the SSM2315 provides excellent MP3 players rejection of common-mode noise on the input. Input coupling Portable gaming capacitors can be omitted if the dc input common-mode voltage Portable electronics is approximately V /2. DD Educational toys The default gain of the SSM2315 is 6 dB, but users can reduce the GENERAL DESCRIPTION gain by using a pair of external resistors (see the Gain section). The SSM2315 is a fully integrated, high efficiency, Class-D audio amplifier. It is designed to maximize performance for mobile The SSM2315 is specified over the industrial temperature range of phone applications. The application circuit requires a minimum 40 C to +85 C. It has built-in thermal shutdown and output of external components and operates from a single 2.5 V to 5.5 V short-circuit protection. It is available in a 9-ball, 1.5 mm 1.5 mm supply. It is capable of delivering 3 W of continuous output power wafer level chip scale package (WLCSP). with <1% THD + N driving a 3 load from a 5.0 V supply. FUNCTIONAL BLOCK DIAGRAM 0.1F 10F VBATT 2.5V TO 5.5V VDD SSM2315 160k 47nF* 80k IN+ OUT+ AUDIO IN+ MODULATOR FET 80k (-) DRIVER IN OUT AUDIO IN 47nF* 160k SD INTERNAL POP/CLICK BIAS SHUTDOWN OSCILLATOR SUPPRESSION GND *INPUT CAPS ARE OPTIONAL IF INPUT DC COMMON-MODE VOLTAGE IS APPROXIMATELY V /2. DD Figure 1. Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 06857-001SSM2315 TABLE OF CONTENTS Features .............................................................................................. 1 Typical Application Circuits ......................................................... 11 Applications ....................................................................................... 1 Theory of Operation ...................................................................... 12 General Description ......................................................................... 1 Overview ..................................................................................... 12 Functional Block Diagram .............................................................. 1 Gain .............................................................................................. 12 Revision History ............................................................................... 2 Pop-and-Click Suppression ...................................................... 12 Specif icat ions ..................................................................................... 3 Output Modulation Description .............................................. 12 Absolute Maximum Ratings ............................................................ 4 Layout .......................................................................................... 13 Thermal Resistance ...................................................................... 4 Input Capacitor Selection .......................................................... 13 ESD Caution .................................................................................. 4 Proper Power Supply Decoupling ............................................ 13 Pin Configuration and Function Descriptions ............................. 5 Outline Dimensions ....................................................................... 14 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 14 REVISION HISTORY 8/08Rev. 0 to Rev. A Changes to Efficiency and Total Harmonic Distortion + Noise Parameters ....................................................... 3 Changes to Ordering Guide .......................................................... 14 2/08Revision 0: Initial Version Rev. A Page 2 of 16