Integrated audio amp delivers high-quality output power. (Analog ICs and discretes).

EDN, December, 2002

National Semiconductor's LM4851--a tiny, 12-bump micro-SMD, three-channel amplifier--routes one monophonic and one stereophonic input to an on-chip monophonic-speaker amplifier or stereo-headphone amplifier in any combination. The same 3-bit "output-mode" configuration word shuts down those amplifiers that a particular task does not need. The part can adjust its stereo input gain from -45.5 to 6 dB in 1.5-dB increments. National Semiconductor designed the monophonic input for cell-phone modules with their own volume controls, so the signal paths from the mono input to the headphone and speaker outputs give 0 and 6 dB of gain, respectively. $1.10 (1000).

* National Semiconductor, 1-800-272-9959, www.national.com. * Enter No. 421