Class-G Headphone Amps suit portable audio applications.July 22, 2008 -
Suited for power-sensitive applications with headphone output, LDS9505 and LDS9504 incorporate Gmax(TM) technology for Class-G amplification and offer 5.5 mW/channel power dissipation to promote battery run-time. Adaptive Rail Amplifier and other technologies eliminate pop and click as well as zipper-noise concerns. Requiring 4 mW quiescent power, standalone products are capable of up to 63 mW in single-ended stereo and 106 mW in mono BTL output, with SNR of 102 dB.
(Archive News Story - Products mentioned in this Archive News Story may or may not be available from the manufacturer.)
Original Press release
Leadis Technology, Inc.
474 Potrero Avenue, Suite A
Sunnyvale, CA, 94085
USA
Leadis Technology Introduces World's First Standalone Class-G Headphone Amplifiers
SUNNYVALE, California, April 22, 2008 - Leadis Technology, Inc. (NASDAQ: LDIS), an analog and mixed-signal semiconductor developer of color display drivers, power management ICs, LED drivers, and audio ICs for portable consumer electronic devices, continues its roll-out of audio ICs with the announcement of sample availability of the world's first standalone Class-G headphone amplifiers, the LDS9505 and LDS9504.
The LDS9505 and LDS9504 are well suited for power sensitive applications such as mobile phones, MP3/PMPs (portable media players), portable gaming, GPS/PNDs (personal navigation devices), notebook computers, and other portable audio products with a headphone output.
The LDS9505 and LDS9504 are optimized for ultra-low power dissipation dramatically increasing battery run-time. Following in the foot-steps of earlier Leadis audio products, the LDS9505 and LDS9504 incorporate Gmax(TM) technology, a proprietary and highly effective implementation of Class-G amplification.
The LDS9505 and LDS9504 also feature the new Leadis ARA(TM) (Adaptive Rail Amplifier), an advanced proprietary charge-pump technology. ARA(TM) tracks the envelope of the audio signal in real-time to dynamically adjust internally generated power supply rails. Minimizing the voltage drop from the power supply rails to the audio waveform envelope eliminates wasted power found in competing headphone amplifiers solutions.
The LDS9505 and LDS9504 require a total of 4mW quiescent power, with ultra-low 5.5mW power dissipation per channel at typical headphone listening levels (0.5mw x 2). Additionally, the devices are capable of up to 63mW in single-ended stereo and 106mW in mono BTL output, with a SNR of 102dB.
High Efficiency - High SNR - No Filters
Using both Leadis Gmax(TM) and ARA(TM) technologies, the LDS9505 and LDS9504 retain the benefit of analog amplifiers (no filters and high signal quality), with a fraction of the power dissipation. "Portable audio manufacturers want increased performance while demanding longer battery life, which creates a challenging design scenario," said Greg Davis, Senior Director of Leadis Audio Business Unit. "They want to keep a smaller battery for the obvious cost, size, and weight benefits yet still get long battery life. At the same time, the headphone amplifier has become a larger percentage of the overall power consumption budget. Our LDS9505 and LDS9504 headphone amplifiers solve this issue by squeezing out every possible minute of battery run-time so a smaller battery can be used."
Excellent "Pop and Click" and "Zipper Noise" Performance
A major concern for manufactures is pop and click sounds during device power-up. Also of concern is "zipper-noise" when the volume is changed. Using a combination of advanced on-chip designs, these objectionable sounds are reduced to virtually zero on the LDS9505 and LDS9504.
Low systems cost
The LDS9505 and LDS9504 have ground-centered outputs that require no output capacitors. This reduces systems cost and board space, while dramatically increasing bass response. Using integrated charge pump circuitry to bias the headphone sleeve to true ground eliminates ground-loop issues that can occur when connecting the output to devices other than headphones, such as audio docking stations.
Highly Flexible Features
o Volume control - The LDS9505 includes a 64 step audio-taper volume control (-59.5dB to +4dB). The LDS9504 implements convenient pin-selectable fixed gains.
o Control interface - An I2C interface controls all device functions including low-power standby, independent headphone mute/enable, headphone mono/stereo, differential or BTL output modes, and a high impedance output. The I2C registers can also be read to verify programming and headphone detection.
o Direct Battery Connection - An integrated LDO allows direct connection to Li-ION batteries and a PSRR (power supply rejection ratio) of over 100dB to effectively eliminate GSM phone interference.
Price, Packaging and Availability
Single-unit pricing for 1,000-piece purchases is $1.80 for the LDS9505 and $1.60 for the LDS9504. Both are packaged in a standard 20-pin 4mm x 4mm QFN, as well as ultra-small chip-resistant Super-CSP(TM) 1.8mm x 2.3mm packaging. Samples are available today, with mass production quantities available Q3 2008. An evaluation board with easy-to-use control software is also available to reduce engineering design-in effort.
About Leadis Technology
Leadis Technology, Inc., headquartered in Sunnyvale, California, designs, develops and markets analog and mixed-signal semiconductors that enable and enhance the features and capabilities of mobile and consumer electronics devices. Leadis' product offerings include color display drivers, which are critical components of displays used in mobile consumer electronic devices; LED drivers, which provide controlled levels of current required to drive light emitting diodes in diverse applications including mobile backlight units; and audio CODEC and FM transmitter ICs, which are integral components in mobile media players and their associated aftermarket accessories. Leadis currently supplies display drivers supporting the major small panel display technologies, including a-Si and LTPS TFT LCD's, color STN LCD's, and color OLED displays, LED drivers supporting mobile backlighting applications, and audio ICs supporting portable media players and aftermarket audio accessories.
Gmax and ARA are trademarks of Leadis Technology Inc. All other trademarks belong to their respective owners.
For more information, visit www.leadis.com.
Contact Information:
Tracy Lam,
Director, World-Wide Marketing Communications,
Leadis International Ltd.,
Tel: +852-21528880
|
|
|
|
|
|
|
| 
