Analog Devices Introduces Class-D Audio Amplifiers for Portable Consumer Electronics; ADI's low-power, SSM2301 and SSM2304 Class-D amplifiers employ sigma-delta modulation to reduce EMI and filterless topology to conserve board space.
NORWOOD, Mass. -- Analog Devices, Inc. (NYSE NYSE
See: New York Stock Exchange : ADI), a global leader in high performance semiconductors for signal-processing applications and the market leader in amplifiers, today introduced two Class-D audio amplifiers designed to meet the low-power, small size, and growing sound quality requirements of portable electronics. A leader in delivering innovative sound processing solutions for home and professional applications, ADI is applying its expertise to Class-D amplifiers that address the space constraints and battery-consumption requirements of cellular handsets, handheld game machines, MP3 players, laptop computers, and handheld media devices.
ADI's SSM SSM
surface-to-surface missile 2301 and SSM2304 Class D amplifiers are designed to efficiently drive speakers in handheld and portable consumer applications by consuming minimal power, employing sigma-delta modulation to reduce electromagnetic interference (EMI (ElectroMagnetic Interference) An electrical disturbance in a system due to natural phenomena, low-frequency waves from electromechanical devices or high-frequency waves (RFI) from chips and other electronic devices. Allowable limits are governed by the FCC. ) emissions, and integrating a filterless topology that eliminates external components.
"Combining the power-saving and space-saving benefits of Class-D audio technology with ADI's linear IC expertise has enabled a portfolio of audio amplifiers that deliver exceptional sound for a range of applications--from portable devices such as cellular handsets and MP3 players, to thin flat panel advanced televisions and multi-channel surround-sound car stereos," said Steve Sockolov, product line director, Precision Signal Processing. "While most Class-D amplifiers use some variation of pulse-width modulation (PWM (Pulse Width Modulation) A modulation technique that generates variable-width pulses to represent the amplitude of an analog input signal. Like its fixed-width pulse density modulation (PDM) cousin, the output switching transistor is on more of the time for a ), ADI's Class-D amplifiers use a sigma-delta pulse density modulation See PDM. (PDM (1) (Product Data Management) An information system used to manage the data for a product as it passes from engineering to manufacturing. The data includes plans, geometric models, CAD drawings, images, NC programs as well as all related project data, notes and ) to reduce the amplitude of spectral components at high-frequencies, thus significantly minimizing EMI emissions."
High Efficiency and Low-Power Consumption for Portable Electronics
The SSM2301 (mono) and SSM2304 (stereo) devices operate at a very high 85 percent efficiency over a wide range of output power levels. The SSM2301 delivers 1.4 W into an 8 ohm load, and the SSM2304 delivers 2 W of power into a 4 ohm load. Both devices operate on a single 2.5 V to 5.5 V supply, have a micro-shutdown mode with a maximum shutdown current of 20 nA, and feature a built-in thermal shutdown and output short circuit protection. The ability to function at very low voltages makes them ideal for applications, such as cellular handsets, where the speaker amplifiers are driven directly from the battery voltage.
Small Packaging and Exceptional Audio Fidelity
The new Class-D audio amplifiers are housed in tiny 8-lead, 3 mm x 3 mm lead-frame chip-scale packaging (LFCSP LFCSP Lead Frame Chip Scale Packaging (analog devices)
LFCSP Lead Frame Chip Scale Package ). Board space is further conserved with a filterless topology that eliminates external output filters.
The SSM2301 and SSM2304 have less than 1 percent total harmonic distortion The total harmonic distortion, or THD, of a signal is a measurement of the harmonic distortion present and is defined as the ratio of the sum of the powers of all harmonic components to the power of the fundamental. plus noise (THD+N THD+N Total Harmonic Distortion + Noise ) when driving peak output loads from a 5 V supply, and a signal-to-noise ratio (SNR See signal-to-noise ratio.
SNR - signal-to-noise ratio ) that is better than 98 dB. The fully-differential input provides excellent rejection of common-mode noise on the input. The amplifiers also include click-and-pop suppression circuitry that reduces audible noise on activation and deactivation--and feature flexible fixed and user-adjustable gain configurations.
The SSM2301 and SSM2304 are the most recent additions to ADI's portfolio of Class-D amplifiers, which also includes the AD199x family of audio power amplifiers. For more information on ADI's audio amplifiers, please visit: www.analog.com/pr/audioamplifier.
Availability and Pricing
The SSM2301 and SSM2304 Class-D audio amplifiers are sampling now, with production quantities available in August 2006, and are priced at $0.55 per unit in 1,000-piece quantities. The devices are fully specified over the industrial temperature range of -40 degrees C to +85 degrees C. An evaluation board with additional measurement filters is also available. For more information, please visit www.analog.com/pr/SSM2301 and www.analog.com/pr/SSM2304.
About Analog Devices
Innovation, performance, and excellence are the cultural pillars on which Analog Devices has built one of the most long-standing, high-growth companies within the technology sector. Acknowledged industry-wide as the world leader in data conversion and signal conditioning technology, Analog Devices serves over 60,000 customers around the world, representing virtually all types of electronics equipment. Celebrating more than 40 years as a leading global manufacturer of high-performance integrated circuits used in analog and digital signal processing See DSP.
Digital Signal Processing - (DSP) Computer manipulation of analog signals (commonly sound or image) which have been converted to digital form (sampled). applications, Analog Devices, Inc. is headquartered in Norwood, Massachusetts, and employs approximately 8,900 people worldwide. It has manufacturing facilities in Massachusetts, California, North Carolina, Ireland, and the Philippines. Analog Devices' common stock is listed on the New York Stock Exchange New York Stock Exchange (NYSE)
World's largest marketplace for securities. The exchange began as an informal meeting of 24 men in 1792 on what is now Wall Street in New York City. and ADI is included in the S&P 500 Index.