Filterless, High Efficiency, Mono 3 W Class-D Audio Amplifier SSM2335 The SSM2335 features a high efficiency, low noise modulation FEATURES scheme that requires no external LC output filters. The modu- Filterless Class-D amplifier with - modulation lation continues to provide high efficiency even at low output No sync necessary when using multiple Class-D amplifiers power. It operates with 93% efficiency at 1.4 W into 8 or 85% from Analog Devices, Inc. efficiency at 3 W into 3 from a 5.0 V supply and has an SNR 3 W into 3 load and 1.4 W into 8 load at 5.0 V supply of >96 dB. Spread-spectrum pulse density modulation is used with <1% total harmonic distortion (THD + N) 93% efficiency at 5.0 V, 1.4 W into 8 speaker to provide lower EMI-radiated emissions compared with other >96 dB signal-to-noise ratio (SNR) Class-D architectures. Single-supply operation from 2.5 V to 5.5 V The SSM2335 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 The device also includes pop-and-click suppression circuitry. Pop-and-click suppression This suppression circuitry minimizes voltage glitches at the Built-in resistors reduce board component count output during turn-on and turn-off, reducing audible noise Default fixed 18 dB or user-adjustable gain setting on activation and deactivation. APPLICATIONS The fully differential input of the SSM2335 provides excellent Mobile phones rejection of common-mode noise on the input. Input coupling MP3 players capacitors can be omitted if the input dc common-mode voltage Portable gaming is approximately V /2. DD Portable electronics The default gain of the SSM2335 is 18 dB, but users can reduce the Educational toys gain by using a pair of external resistors (see the Gain section). GENERAL DESCRIPTION The SSM2335 is specified over the industrial temperature range The SSM2335 is a fully integrated, high efficiency, Class-D audio of 40 C to +85 C. It has built-in thermal shutdown and output amplifier. It is designed to maximize performance for mobile short-circuit protection. It is available in a 9-ball, 1.5 mm phone applications. The application circuit requires a minimum 1.5 mm wafer level chip scale package (WLCSP). of external components and operates from a single 2.5 V to 5.5 V supply. It is capable of delivering 3 W of continuous output power 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 SSM2335 160k 47nF* 20k IN+ OUT AUDIO IN+ MODULATOR FET 20k (-) DRIVER IN OUT+ AUDIO IN 47nF* 160k SD INTERNAL POP-AND-CLICK BIAS SHUTDOWN OSCILLATOR SUPPRESSION GND *INPUT CAPACITORS ARE OPTIONAL IF INPUT DC COMMON-MODE VOLTAGE IS APPROXIMATELY V /2. DD Figure 1. Rev. 0 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. 07551-001SSM2335 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 Power Supply Decoupling ......................................................... 13 Pin Configuration and Function Descriptions ............................. 5 Outline Dimensions ....................................................................... 14 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 14 REVISION HISTORY 10/08Revision 0: Initial Version Rev. 0 Page 2 of 16