Geneva — STMicroelectronics unveiled a filterless 3-watt Class D power amplifier today for mobile phones and other portable applications that is said to provide higher audio power output while preserving and extending battery life.

STMicro's Class D TS4962 amplifier can be used for gaming, polyphonic ringers and speaker phone applications, as well as PDAs and laptop computers. It provides 3 W of output power into a 4-ohm loudspeaker when operating on a 5-volt power supply, and achieves 88 percent efficiency — far higher than that of the Class AB amps commonly used in mobile phones today, the company said.

The TS4962 audio power amplifier is designed to operate over a wide 2.4 V to 5.5 V supply voltage range. Its quiescent current with no input signal is 2.3 milliamps typical, and standby current when powered down using its active-low control line is 10 nanoamps. Pop and click reduction circuitry provides low on/off switching noise while allowing the amplifier to start within 5 milliseconds, according to STMicro. The gain is set using two external resistors.

A fully differential design is said to reduce RF rectification effects and eliminate the need for a bypass capacitor. Output power is 3 W into 4 ohms or 1.75 W into 8 ohms, at 10 percent maximum total harmonic distortion plus noise (THD+N), on a 5-V supply. At 1 percent maximum THD+N, output power is 2.3 W into 4 ohms on a 5-V supply, or 0.75 W on a 3-V supply. Signal to noise ratio is typically 85 dB.

The TS4962 amplifier is available in a lead-free, 1.6-mm square, 9-bump FCP, and is supported by a development board, which includes the device pre-mounted onto a flip-chip to DIP adapter for easier handling during evaluation.

Available in production volume now the device is priced at 55 cents each in 5,000-piece quantities. Click here for STMicro’s TS4962 data sheet.

STMicroelectronics , 1-888-787-3550, www.ST.com.