High-efficiency Class G stereo amplifier IC with digital I2S interface offers power saving benefits

July 05, 2012 // By Paul Buckley
Toshiba Electronics Europe has expanded its family of ultra-low power stereo headphone amplifier ICs with a new class-G device that claims to combine outstanding audio performance with a digital I2S interface.

The TC94B15WBG is ideal for mobile phones, MP3 players, Bluetooth headsets, portable navigation equipment and other battery-powered devices requiring efficient, high-quality audio amplification.

Class-G amplifiers operate at low supply voltages for the majority of audio-signal levels, but are able to increase dynamic range temporarily when high signal levels are received. This enhances energy efficiency and reduces overall power consumption. As a result, Toshiba’s new amplifier achieves significantly higher efficiency than conventional class-A/B alternatives while retaining inherently low audio distortion. It will also allow customers to build ultra low-power headphone amplifiers while avoiding the high costs and complex filtering associated with a class-D amplifier.

Toshiba’s TC94B15WBG has been designed to minimise component count and board space. Built-in DC/DC converter circuitry facilitates direct connection to the battery; an integrated Sigma-Delta DAC stage with digital and low-pass filtering supports the I2S digital interface; and there is no requirement for output coupling capacitors. In addition, internal volume control (with muting) enhances the system dynamic range, allowing adjustment from -63 db to 0 dB in 32 steps while further reducing the need for external components. An integrated I2C port provides a convenient, industry-standard interface for volume control and diagnostic monitoring.

The TC94B15WBG delivers high audio performance, with a typical THD+N rating of less than 0.02% and a typical SNR of 92 dB. Typical quiescent current is down to 1.8 mA, while a 1 µA standby mode allows designers to use power management to further increase system energy efficiency for maximum battery lifetime. Analogue voltage supply (AVDD) and digital voltage supply (DVDD) ranges are 1.65 V to 1.95 V and 2.3 V to 4.8 V respectively.

Supplied in a miniature 20-pin 0.4 mm-pitch wafer-level chip-scale package (WCSP), the TC94B15WBG has dimensions of 2.43 mm x 2.03 mm.

Visit Toshiba at www.toshiba-components.com