National IC integrates speaker, headphone amplifiers

National Semiconductor Corp. has announced the release of the LM4854 IC that integrates the company's Boomer stereo headphone amplifier with a mono speaker amplifier to form a single-chip solution for portable electronic devices such as cellphones, PDAs, and notebook PCs.

The chip integrates a 1.9W mono speaker amplifier and an 85mW stereo headphone amplifier, for use in 3V and 5V systems requiring a mono speaker output and a headphone output. The device features a turn on/off time of 0.1ms and uses a headphone sense pin when switching from mono BTL to an SE headphone configuration.

An advanced "click and pop" suppression circuitry is also included for quieter turn-on and turn-off. Other features include an active-low micropower shutdown mode, "instant-on" low-power standby mode, and thermal shutdown protection circuitry.

The chip operates from 2.4V to 5.5V and draws 165A (3V) or 275A (5V). It is rated for operation from -400C to 850C.

The LM4854 is available in 12-bump micro SMD, 14-pin LLP, and 14-pin TSSOP casing, and is priced at $1.10 in 10,000-unit quantities.