Mono, 2W, Switch-Mode (Class D) Audio Power Amplifier

The MAX4295 mono, switch-mode (Class D) audio power amplifier operates from a single +2.7V to +5.5V supply. The MAX4295 has > 85% efficiency and is capable of delivering 2W continuous power to a 4Ω load, making it ideal for portable multimedia and general-purpose high-power audio applications.

The MAX4295 features a total harmonic distortion plus noise (THD+N) of 0.4% (fOSC = 125kHz), low quiescent current of 2.8mA, high efficiency, and clickless power-up and shutdown. The active-low SHDN input disables the device and limits supply current to < 1.5µA. Other features include a 1A current limit, thermal protection, and undervoltage lockout.

The MAX4295 reduces the number of required external components. Internal high-speed power-MOS transistors allow operation as a bridge-tied load (BTL) amplifier. The BTL configuration eliminates the need for isolation capacitors on the output. The frequency-selectable pulse-width modulator (PWM) allows the user to optimize the size and cost of the output filter.

The MAX4295 is offered in a space-saving 16-pin QSOP or narrow SO package.

Applications

* AC Amplifiers * Battery-Powered Speakers * Boom Boxes * Cordless Phones * Game Cards * Palmtop/Notebook Computers * PDA Audio * Portable Equipment * Sound Cards

* +2.7V to +5.5V Single-Supply Operation

* 2W/Channel Output Power at 5V

* 0.7W/Channel Output Power at 3V

* 87% Efficiency (RL = 4Ω, POUT = 2W)

* 0.4% THD+N (RL = 4Ω, fOSC = 125kHz)

* Logic-Programmable PWM Frequency Selection (125kHz, 250kHz, 500kHz, 1MHz)

* Low-Power Shutdown Mode

* Clickless Transitions Into and Out of Shutdown

* 1A Current Limit and Thermal Protection

* Available in Space-Saving Packages

* 16-Pin QSOP or Narrow SO