Amplifiers have lowest power consumption in class says austriamicrosystems
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Analogue ic specialist, austriamicrosystems, has launched 30mW headphone amplifiers which it claims continuously adjust the supply rails in response to the input signal, and drastically minimise power consumption compared to traditional Class AB amplifiers.
The AS3560 Class G and AS3561 Class H stereo headphone amplifiers are designed for mobile phones, portable navigation devices, music / media players and any media device that uses headphones.
Class G topology switches between 3 power rails, while Class H adapts the power rail to whatever power is needed to drive the headphone volume. Both devices use differential line inputs to minimise the effects of ground noise and EMI susceptibility and also feature quiescent current of 1mA with both channels enabled. The shutdown current is less than 5µA.
Audio performance is >100dB SNR @ 1Vrms and THD of 0.02 % at 16Ω, while the integrated charge pump generates a symmetric negative supply for true ground output signal levels. An I2C bus allows volume control with 32 gain steps as well as independent channel control.
The AS3560 and AS3561 are available in a 16ball 1.6 x 1.6mm WL-CSP package and both operate over a temperature range of -30 to 85°C.
