Class D audio amplifier for flat panel TVs features digital power limit and selectable gain
August 03, 2011 // Paul Buckley
ON Semiconductor has introduced the NCS8353 stereo audio amplifier, a Class D device with high efficiency levels (>87%), that elimates the need for the inclusion of a heatsink in the system design.
Aimed at the flat panel TV market the device can be powered from the existing 24 V backlight rail in the TV system and is capable of delivering a continuous output power of up to 20 W per-channel into an 8 Ω bridge tied load (BTL).
The Pulse Width Modulation (PWM) technique utilized within the Class-D architecture permits filter-less operation in certain circumstances by using the speakers themselves as an LC filter. This can significantly improve total bill of material costs as the additional components typically required to filter Electro-Magnetic Interference (EMI) can be omitted.
Four selectable gain ranges are supported: 20 dB, 26 dB, 32 dB, and 36 dB. An integrated digital power limiter can be set, using two external bits, to deliver a specific output (10 W, 12 W, 15 W, or 20 W). This protects the TV speakers from high amplitude input spikes. A shutdown function reduces the quiescent current drawn by the amplifier to 100 µA typical, while the mute feature ensures that audio is not present at the output during audio source switching.
In order to permit uninterruptable audio operation at lower output powers, should the internal temperature rise above the junction threshold of 150 °C, the internal gain of the device is slowly reduced. The combination of gain reduction and internal power dissipation results in a stable maximum junction temperature of approximately 140 °C. The output stage will completely shut down if the junction temperature rises above 160 °C. The power stage is re-enabled once the device junction temperature cools to below 130 °C.
If a short circuit event is detected, the output stage of the devices is completely disabled and an internal counter activated. After a 100 ms period the output stage will attempt to reactivate, with the cycle continuing until the short is removed.
The NCS8353 is housed in a compact 5 mm x 5 mm, Pb−Free, 32-pin QFN package and is priced at $0.78 per unit in 10,000 unit quantities.
Visit ON Semiconductor at www.onsemi.com.
Rohm's European Design Center in growth phase
November 21, 2014
At Electronica EE Times Europe caught up with Michael Davis European R&D director at the European Design Center (EDC) of ...
Combo inertial sensor market on 19% CAGR, says Yole.
US, China pushing industrial chip market growth, says IHS
LA Auto Show: Hydrogen fuel cell drive is back
Opening up the IoT data flood gates
Polarizing filter reduces energy drain from smartphone displays
November 21, 2014
A polarizing filter has been developed by University of Utah engineers which allows in more light, leading the way for mobile ...
From warm to cool white: colour-temperature tunable LEDs
System provides high-volume solution for flexible OLED displays
Isabellenhütte diversifies channels, clientele
- Halogen-free options and increased performance for terminal blocks
- Wireless Power User Guide
- Secure is the New Smart
- 5 Best Practices for Designing Flexible Test Stations
InterviewFreescale CEO: 'IoT isn't just buzz'
Coming after the solid third quarter results that produced higher operating margins and improving cash flow, Freescale Semiconductor's CEO Gregg Lowe had every reason to be chipper and lively when EE Times ...
Filter WizardCheck out the Filter Wizard Series of articles by Filter Guru Kendall Castor-Perry which provide invaluable practical Analog Design guidelines.
Linear video channel
READER OFFERRead more
This month, Cherry is giving away five of its Energy Harvesting Evaluation kits, worth over 266 Euros each, for EETimes Europe's readers to win. Cherry's energy harvesting technology benefit mostly applications where a complex wire assembly and/or batteries would be inappropriate.
The required RF-energy is created by the mechanical actuation of the switch and the data is transmitted...MORE INFO AND LAST MONTH' WINNERS...
December 15, 2011 | Texas instruments | 222901974
Unique Ser/Des technology supports encrypted video and audio content with full duplex bi-directional control channel over a single wire interface.
Most popular news
- Could magnesium battery innovation end lithium's dominance?
- From warm to cool white: colour-temperature tunable LEDs
- Li-Fi communication module wirelessly transfers data at 1-Gbps
- Supercapacitor innovation promises panel-powered cars in five years
- Rebranding the revolution: the future of IoT is embedded