Product category:
Analogue and Mixed Signal ICs
News Release from: National Semiconductor | Subject: LM4910 and LM4911
Edited by the Electronicstalk Editorial
Team on 04 April 2002
Amplifiers shrink space for headphone
drive
Two new Boomer stereo headphone amplifiers from National Semiconductor have space-saving features that make them ideal for headphone applications in small portable devices such as mobile phones.
Two new Boomer stereo headphone amplifiers from National Semiconductor have space-saving features that make them ideal for headphone applications in small, portable devices such as mobile phones, PDAs, MP3 players and other portable electronic equipment "National Semiconductor is continuing to expand the Boomer portfolio with two new market leaders", said Thomas Eikenberg, marketing engineer at National's audio amplifier product group in Europe
This article was originally published on Electronicstalk on 5 Jan 2001 at 8.00am (UK)
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"The LM4910 and LM4911 feature the Boomer family's revolutionary output capacitorless (OCL) headphone design, which eliminates two output coupling capacitors that are needed in all headphone applications.
The LM4910 is the market's first 5V headphone amplifier capable of eliminating output coupling capacitors, affording the customer substantial savings in board space and manufacturing time.
The LM4911 is the industry's first 5V headphone amplifier with selectable OCL mode or capacitive coupled mode available in 8-pin MSOP packaging.
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National Semiconductor has introduced a full-featured 500mA LDO regulator for medium-current applications in computing devices and portable products.
Boomer shrinks stereo headphone amplification
New from National Semiconductor, the LM4811 Boomer audio amplifier is a 105mW stereo headphone amplifier for use in 3 and 5V systems requiring a headphone output and volume control.
These features provide flexibility in design with minimal board space requirements".
The LM4910 is an audio power amplifier primarily designed for headphone applications in portable devices.
It is capable of delivering 35mW of continuous average power to a 32ohm BTL load with less than 1% distortion (THD+N) from a 3.3V DC power supply.
National's LM4910 uses a new circuit topology that eliminates output coupling capacitors and half-supply bypass capacitors.
This device contains advanced pop and click circuitry, which eliminates noises caused by transients that would otherwise occur during turn-on and turn-off.
The LM4910 provides high-quality output power with a minimal amount of external components.
Because it does not require any output coupling capacitors, half-supply bypass capacitors, or bootstrap capacitors, it is ideally suited for low-power portable applications where minimal space and power consumption are primary requirements.
Additionally, the LM4910 features a low power consumption shutdown mode, activated by driving the shutdown pin with logic low.
The LM4910 also features an internal thermal shutdown protection mechanism and is unity-gain stable.
It can be configured using external gain-setting resistors.
The LM4911 features a low-power consumption shutdown mode and a power mute mode that allow for faster turn-on time with less than 1 mV voltage change at outputs on release.
It is capable of delivering 40mW per channel of continuous average power into a 16ohm load, or 25mW per channel into a 32ohm load at 1% THD from a 3V power supply.
Additionally, the LM4911 has an internal thermal shutdown protection mechanism.
This device is unity-gain stable and may be configured with external gain-setting resistors.
The LM4910 is available now in 8-pin SOIC and MSOP packaging and is priced at $0.75.
The LM4911 is available in 8-pin MSOP packaging and is priced at $0.75.
Both product prices are for 1000-unit quantities.
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