Audio Amp Squelches Input Noise November 2005 Issue Published Date: November 04, 2005
The TS4994, a differential audio power amplifier, delivers up to 1.2W of continuous power into an 8Ω load at 5V with a total harmonic distortion of 1% at 1 kHz. Reducing input noise, the device specifies a common-mode rejection of 85 dB and a power-supply rejection ratio of 100 dB, both at 217 Hz with grounded inputs. Operating voltage ranges from 2.5V to 5.5V, and the chip's standby mode can be programmed via an external signal to be either active high or low. Standby power consumption is 10 nA and start-up time is 15 ms. Other features include thermal shutdown protection and common-mode feedback circuitry that allows the outputs to be biased to half the supply voltage, regardless of input common-mode voltage. Available in a nine-bump, 0.5-mm pitch flip-chip package as a DFN10 or MiniSO-8, price is $0.60 each/5,000. STMICROELECTRONICS INC., Lexington, MA. (781) 861-2650.
