MAX9850 Datasheet, PDF (1/36 Pages) Maxim Integrated Products – Stereo Audio DAC with DirectDrive Headphone Amplifier

19-3454; Rev 0; 11/04
Stereo Audio DAC with DirectDrive
Headphone Amplifier
General Description
The MAX9850 is a low-power, high-performance stereo
audio DAC with an integrated DirectDrive™ headphone
amplifier. The MAX9850 is designed to meet the board
space and performance requirements of portable devices
such as cell phones and MP3 and portable DVD players.
The MAX9850 uses Maxim’s patented DirectDrive
headphone technology that produces a ground-biased
analog audio output from a single supply, which allows
for driving the headphones directly from the amplifier
outputs without large DC-blocking capacitors. This fea-
ture saves board space, provides higher click/pop sup-
pression, and improves low-frequency (bass) response.
The architecture does not require the headphone jack
to be biased to a DC voltage and thus allows for a con-
ventional, grounded chassis design.
The MAX9850’s flexible clocking circuitry utilizes any
available system clock up to 40MHz, eliminating the
need for an external PLL and multiple crystal oscillators.
The DAC supports a wide range of sample rates from
8kHz to 48kHz in both master and slave modes, making
the MAX9850 the easiest to use and most versatile audio
DAC available. It can also be operated like traditional
synchronous DACs, at any integer-oversampling ratio.
The audio DAC receives input data over a flexible
3-wire interface that supports up to 32 bits of left-justi-
fied, right-justified, or I²S-compatible audio data. Stereo
audio line inputs are provided to either mix analog
audio with the digital input stream, or to drive the head-
phone outputs directly. Mode settings, headphone
amplifier volume controls, and shutdown for both the
headphone and line outputs are programmed through a
2-wire, I²C-compatible interface.
The MAX9850 is fully specified over the -40°C to +85°C
extended temperature range and is available in a low-
profile, 28-pin thin QFN package (5mm x 5mm x 0.8mm).
Applications
MP3/Portable Multimedia Players
Cell Phones/Smart Phones
Portable DVD Players
Purchase of I²C components from Maxim Integrated Products,
Inc. or one of its sublicensed Associated Companies, conveys
a license under the Philips I²C Patent Rights to use these com-
ponents in an I²C system, provided that the system conforms to
the I²C Standard Specification as defined by Philips.
Features
♦ 1.8V to 3.6V Single-Supply Operation
♦ 30mW Stereo Headphone Output Power with
1.8V Supply
♦ DirectDrive Outputs Eliminate DC-Blocking
Capacitors
♦ 91dB PSRR at 1kHz
♦ Any Master Clock Up to 40MHz
♦ Flexible I²S-Compatible Digital Audio Interface
♦ I²C Headphone Volume and Mute Control
♦ Stereo Line Inputs and Outputs
♦ Clickless/Popless Operation
♦ 2-Wire (I²C)-Compatible Control Interface
♦ Available in 28-Pin Thin QFN Package
Ordering Information
PART
MAX9850ETI
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
28 Thin QFN-EP*
*EP = Exposed Paddle. Package code T2855-6 (see Package
Information section).
Pin Configuration appears at end of data sheet.
Block Diagram
SDIN
BCLK
LRCLK
SDA
SCL
ADD
GPIO
MCLK 1.8V TO 3.6V
DIGITAL
PLL
DIGITAL
AUDIO
INR
MAX9850
DAC
+
DAC
+
I²C
INL
OUTR LINE
OUT
HPR
HPL
OUTL LINE
OUT
________________________________________________________________ Maxim Integrated Products 1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.