Date: 01/09/2009

Maxim's stereo class-D audio subsystem with DirectDrive headphone amplifier

Maxim has introduced the MAX9879, a new stereo audio subsystem for integration and performance that comes in a pack of high-efficiency, high-power, stereo Class D speaker amplifier, a DirectDrive stereo headphone amplifier, and an ultra-low-noise, analog bypass switch. By providing high output power from a lithium-ion battery, the MAX9879 is ideal for cellular phones, portable media players (PMPs), and other applications that require high audio quality, output power, and efficiency.

The MAX9879 offers click-and-pop performance with no audible artifacts at power on/off and also high RF/TDMA noise rejection, which simplifies the design iteration process.

Maxim's filterless class D amplifiers with active emissions limiting technology provide Class AB performance with Class D efficiency.

Other key features are,

Better than 9dB margin under EN 55022 class B limits with no filter components
Low RF susceptibility design rejects TDMA noise from GSM radios
Input mixer with user defined input mode
Volume control
User-defined input architecture with preamplifier gain settings
Stereo 715mW speaker output (RL = 8Ù, VDD = 3.7V)
Stereo 58mW headphone output (16Ù, VDD = 3.7V)
Low 0.04% THD+N at 1kHz (Class D Power Amplifier)
Low 0.018% THD+N at 1kHz (Headphone Amplifier)
88% Efficiency (RL = 8Ù, POUT = 750mW)
1.6Ù Analog switch for speaker amplifier bypass
High speaker amplifier PSRR (72dB at 217Hz)
High headphone amplifier PSRR (84dB at 217Hz)
I2C Control
Hardware and software shutdown mode
Ultra-low click and pop
Robust design with current and thermal protection


Operating temperature range: -40°C to +85°C

Package: 2.5mm x 3mm, 30-bump UCSP package
Price: Starts at $1.35 for 1k pieces.
Availability: Evaluation kit available
For more details visit www.maxim-ic.com