Date: 23/02/2010

Mono audio systems integrate Class D and Class H amps for portable apps

Maxim has introduced the MAX97000/MAX97001* /MAX97002, a new family of mono audio subsystems that combine a high-efficiency, Class D mono speaker amplifier with distortion limiter, a DirectDrive II Class H stereo headphone amplifier, and a low-noise, analog bypass switch. With 87%(typ) of high efficiency and audio quality, the MAX97000-MAX97002 are suitable for cellular phones, portable media players (PMPs), and other applications that require high audio quality, output power, and efficiency.

The key features of the new mono audio subsystems are,

2.7V to 5.5V speaker supply voltage
1.6V to 2V headphone supply voltage
700mW of speaker output (VPVDD = 3.7V, ZSPK = 8Ohm + 68µH)
37mW/channel headphone output (RHP = 16Ohm)
Low-emission Class D amplifier
Efficient Class H headphone amplifier
Ground-referenced headphone outputs
2 stereo single-ended/mono differential inputs
Integrated distortion limiter (speaker outputs)
Integrated DPST analog switch
No clicks and pops
TDMA noise free

The subsystems also feature input mixing, volume control, and a flexible, user-defined input architecture with preamplifier gain settings. All controls are enabled through an I²C interface.

Maxim's DirectDrive II technology utilizes a dual-mode internal charge pump that operates at ±0.9V for low signal levels, only switching to ±1.8V for signals that require high output power. This architecture minimizes power consumption while avoiding the signal discontinuity problems that plague other Class H implementations.

In addition to boosting efficiency, the DirectDrive II architecture eliminates the need for large DC-blocking capacitors by producing a ground-referenced output from a single supply.

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

Package;
MAX97000: 2.0mm x 2.0mm, 25-bump WLP with a 0.4mm pitch package
MAX97001/MAX97002: 2.0mm x 2.5mm, 20-bump WLP package with a 0.5mm pitch
Price:
MAX97000: Starts at $0.75 for 1k pieces
MAX97001/MAX97002: Starts at $0.83 for 1k pieces
Availability: Now

For more information, go to www.maxim-ic.com