STMicroelectronics Unveils Combined Analog Switch, Audio Amplifier IC
December 15, 2008 // Published as a news service by IHS
By consolidating an analog switch achieving -80 dB isolation and a 1.6 watt (W) class-D amplifier in a single package, the TS4961T from STMicroelectronics (ST) simplifies board design and saves space in cell phones and personal media players, according to the company.
Using this device, designers can implement both functions within a 3 millimeter by 3 millimeter quad flat no-lead (QFN) 16 footprint instead of using two separate components.
ST said the TS4961T is optimized for use in battery-operated devices. The combination switch/amplifier operates within a 2.4 volt (V) to 4.3 V supply voltage range, consuming 2 mA operating current at 3 V, and featuring a 10 nA shutdown mode to extend battery life. The amplifier drives up to 1.6 W into a 4 Ohm load, or 0.95 W into an 8 Ohm load.
The integrated audio switch is a dual single pole, single throw (SPST) complementary metal-oxide semiconductor (CMOS) device that enables higher channel isolation than comparable combined amplifier/switch integrated circuits (ICs), according to ST.
Break-before-make switching enables command of line-out and speaker-out sources, such as the baseband audio and codec output in a cell phone. The filterless class-D amplifier achieves less than 1% total harmonic distortion, low pop and click noise and power supply rejection up to -63 dB at 217 Hz.
The gain is adjusted using two external resistors. By achieving 88% operating efficiency, the amplifier simplifies thermal management and reduces power consumption, enabling further savings in size, cost and weight of the end product, ST said. Thermal shutdown protection is also included.
The TS4961T, which features Restriction of Hazardous Substances (RoHS)-compliant Ecopack packaging, is available immediately in sample or production quantities.
Source: STMicroelectronics (ST).