Integrated Circuit drives mobile phone headset and speaker.
Press Release Summary:
Model TS4851 includes digital volume control and audio amplifier. It also offers controllable gain for left and right audio channels, and separate mono input for a microphone. Model TS4855 includes extra input channel for handsfree microphone and audio amplifier that delivers 1.1 W of continuous RMS output power into 8 Ohm speaker with 1% THD+N. Each part has 32-step digital volume control and 8 output modes, and includes pop and click reduction circuitry.
Original Press Release:
STMicroelectronics Introduces Parts to Cut Component Count for Cellphone Audio Circuits
Will drive headset and speaker
Geneva, October 31, 2003 - STMicroelectronics (NYSE: STM) has introduced a headset and speaker driver IC for mobile phones that includes an audio amplifier and digital volume control. The parts need almost no external circuitry.
The TS4851 offers controllable gain for left and right audio channels, plus a separate mono input for a microphone without a gain control. The TS4855 has an additional gain path that can be used for another input, such as a hands-free microphone.
The TS4851 includes an audio amplifier that can deliver a typical 400mW of continuous RMS output power into an 8W load with 1% THD+N. A headset driver will drive a typical 30mW of continuous average power into each channel of a stereo 32Ohm bridged-tied load with 0.5% THD+N, given a 3.3V supply.
The TS4855 includes an audio amplifier that can deliver a typical 1.1W of continuous RMS output power into an 8Ohm speaker with 1% THD+N. A headset driver will drive a typical 85mW of continuous average power into each channel of a stereo 32Ohm bridged-tied load with 0.5% THD+N, given a 5V supply.
The TS4855 also offers an extra input channel for a handsfree microphone.
Both parts have a 32-step digital volume control and eight output modes, which control the combination of headset channels, speaker, inputs and volume that is used. The digital volume and output modes are controlled through a three-wire SPI bus interface.
Both parts support rail to rail inputs and outputs, and include pop and click reduction circuitry. Both work from a supply voltage of between 3V and 5V. The current drain when they are in shutdown mode is a typical 0.1µA. The parts feature thermal shutdown protection.
The parts are delivered in a flip chip package with 18 asymmetrically arranged bumps. They are currently available at 1.35US$ in quantities of 1K units.
Further information on these products is available at www.st.com/stdlinear. Complete datasheets can be found on-line at the following URLs:
TS4851: st.com/stonline/books/pdf/docs/8948.pdf
TS4855: http://st.com/stonline/books/pdf/docs/8949.pdf
About STMicroelectronics
STMicroelectronics is a global leader in developing and delivering semiconductor solutions across the spectrum of microelectronics applications. An unrivalled combination of silicon and system expertise, manufacturing strength, Intellectual Property (IP) portfolio and strategic partners positions the Company at the forefront of System-on-Chip (SoC) technology and its products play a key role in enabling today's convergence markets. The Company's shares are traded on the New York Stock Exchange, on Euronext Paris and on the Milan Stock Exchange. In 2002, the Company's net revenues were $6.32 billion and net earnings were $429.4 million. Further information on ST can be found at www.st.com.
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