Noise-Free Audio Amp suits portable/wireless applications.

Press Release Summary:

Able to deliver 1.35 W of output power to 8 ohm speaker or 1.1 W to 4 ohm speaker, NCP2991 Class AB audio amp has THD of 0.015% and features -103 dB power supply rejection ratio that eliminates any noise generated by fluctuation of battery supply voltage. It is also resistive to TDMA noise that occurs during GSM transmission and exhibits zero pop-and-click noise at start-up and shut-down. Selectable start-up between 15 and 20 msec enables use of shut-down mode, which consumes 20 nA.

Original Press Release:

ON Semiconductor Introduces High Quality Class AB Audio Amplifier for Portable and Wireless Applications

New NCP2991 is a noise-free 1.35 watt audio amplifier with industry-leading -103 decibels power supply rejection ratio

ELECTRONICA - Munich, Germany - Nov. 11, 2008 - ON Semiconductor (Nasdaq: ONNN), a leading global supplier of high performance, energy efficient, silicon solutions has introduced the NCP2991, a new generation of Class AB audio amplifier dedicated to providing superior audio performance without sacrificing power efficiency for portable and wireless applications.

"Having a clear, noise-free audio output is crucial to the user's satisfaction of a cell phone or portable media device," said Manor Narayanan, vice president and general manager of ON Semiconductor's Digital and Consumer Products Group. "Hardware designers, however, typically encounter unexpected noise issue coming from the audio system. ON Semiconductors new Class AB amplifier ensures noise-free amplification and is resistive to external noise sources so it guarantees a high quality audio performance. By enforcing our amplifier's robustness, we expect to minimize the audio designer's effort and design cycle time."

The NCP2991 addresses two of the most crucial requirements in today's portable and wireless audio applications, namely customer demand for noise-free audio amplification and fast response time.

Noise-free audio amplification
NCP2991 offers a superior Power Supply Rejection Ratio (PSRR) of -103 decibels (dB) that eliminates any noise that may be generated by the fluctuation of battery supply voltage. The device is highly resistive to the so-called "TDMA noise" (Time Division Multiple Access) that occurs during the Global System Mobile (GSM) transmission. Additionally, the device guarantees zero pop-and-click noise at start-up and shut-down, which apply to all input configurations. Its very low typical Total Harmonic Distortion (THD) level (0.015 percent) further ensures high fidelity audio output.

Ultra fast start-up time
The start-up time of NCP2991 is selectable between 15 milliseconds (ms) and 20 milliseconds (ms). Thanks to this very fast start-up time, the NCP2991 can be kept in shut-down mode when it is not in use. Therefore, most of the time, the NCP2991 consumes only 20 nanoamps (nA). Fast audio response is especially crucial for portable devices with touch screen, since the audio feedback is perceived by end-user as the indication of the total system's responsiveness.

Additional Features
The NCP2991 is capable of delivering 1.35 watts (W) of output power to an 8 ohm speaker, or 1.1 W to a 4 ohm speaker. It also has built-in thermal overload protection circuitry to disable the device's operation in case of an over-temperature situation.

"The NCP2991 is a key addition to ON Semiconductor's portfolio of solutions targeted at the four primary subsystems typically found in most portable applications." said Wes Reid, ON Semiconductor director of strategic marketing and systems engineering for Digital Consumer products. "This device specifically addresses needs within the Audio subsystem. ON Semiconductor also offers solutions for the lighting/display, power management and interconnect subsystems found in handheld and portable devices."

Packaging and Pricing
Available in the industrial standard 1.45 mm x 1.45 mm x 0.6 mm µBump package and is budgetary priced at $0.22 USD per unit in 3,000 unit quantities.

For additional technical information visit or contact Crystal Lam (Product Marketing Manager) at

About ON Semiconductor
With its global logistics network and strong product portfolio, ON Semiconductor (Nasdaq: ONNN) is a preferred supplier of high performance, energy efficient, silicon solutions to customers in the power supply, automotive, communication, computer, consumer, medical, industrial, mobile phone, and military/aerospace markets. The company's broad portfolio includes power, analog, DSP, mixed-signal, advance logic, clock management, nonvolatile memory and standard component devices. Global corporate headquarters are located in Phoenix, Arizona. The company operates a network of manufacturing facilities, sales offices and design centers in key markets throughout North America, Europe, and the Asia Pacific regions. For more information, visit

ON Semiconductor and the ON Semiconductor logo are registered trademarks of Semiconductor Components Industries, LLC. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. Although the company references its website in this news release, such information on the website is not to be incorporated herein.

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