General Description

The MAX9721 fixed-gain, stereo headphone amplifier is ideal for portable equipment where board space is at a premium. The MAX9721 uses a unique, patented DirectDrive architecture to produce a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, board space, and component height. Fixed gains of -2V/V (MAX9721A), -1.5V/V (MAX9721B), and -1V/V (MAX9721C) further reduce external component count.

Features

♦ Single Cell, 0.9V to 1.8V Single-Supply Operation

♦ Fixed Gain Eliminates External Feedback Network

    MAX9721A: -2V/V

    MAX9721B: -1.5V/V

    MAX9721C: -1V/V

♦ Ground-Referenced Outputs Eliminate DC Bias

♦ No Degradation of Low-Frequency Response Due to Output Capacitors

♦ 20mW per Channel into 32Ω

♦ Low 0.006 THD+N

♦ High PSRR (80dB at 1kHz)

♦ Integrated Click-and-Pop Suppression

♦ Low Quiescent Current (2.2mA)

♦ Low-Power Shutdown Control

♦ Short-Circuit Protection

♦ ±8kV ESD-Protected Amplifier Outputs

♦ Available in Space-Saving Packages

    12-Bump UCSP (1.54mm x 2.02mm x 0.6mm)

    12-Pin Thin QFN (4mm x 4mm x 0.8mm)

Applications

    MP3 Players

    Cellular Phones

    PDAs

    Smart Phones

    Portable Audio Equipment