19-1288; Rev 2; 12/11
Low-Power Audio CODEC with
DirectDrive Headphone Amplifiers
MAX9856
General Description
Features
o 1.71V to 3.6V Single-Supply Operation
o Stereo 30mW DirectDrive Headphone Amplifier
o Stereo 1V DirectDrive Line Outputs
The MAX9856 is a high-performance, low-power stereo
audio CODEC designed for MP3, personal media play-
ers (PMPs), or other portable multimedia devices.
Using on-board stereo DirectDrive® headphone ampli-
fiers, the CODEC can output 30mW into stereo 32Ω
headphones while operating from a single 1.8V power
supply. Very low 9mW playback power consumption
makes it an ideal choice for battery-powered applica-
tions. The MAX9856 provides microphone input ampli-
fiers, plus flexible input selection, signal mixing, and
automatic gain control (AGC). Comprehensive load-
impedance sensing allows the MAX9856 to autodetect
most common audio and audio/video headset and jack
plug types.
RMS
(V
= 1.8V) and Stereo Line Inputs
DD
o Low-Noise Stereo and Mono Differential
Microphone Inputs with Automatic Gain Control
and Noise Quieting
o 9mW Playback Power Consumption (V
o 91dB 96kHz 18-Bit Stereo DAC
o 85dB 48kHz 18-Bit Stereo ADC
= 1.8V)
DD
o Supports Any Master Clock Frequency from
10MHz to 60MHz
o ADCs and DACs Can Run at Independent Sample
Rates
Outputs include stereo DirectDrive line outputs and
DirectDrive headphone amplifiers. The stereo ADC can
convert audio signals from either internal or external
microphones that can be configured for single-ended
or differential signal inputs. Line inputs can be config-
ured as stereo, differential, or mono and fed through
one channel of the microphone path. The analog inputs
selected can be gain ranged or mixed with other input
sources prior to conversion to digital. The ADC path
also features programmable digital highpass filters to
remove DC offset voltages and wind noise.
o Flexible Audio Mixing and Volume Control
o Clickless/Popless Operation
o Headset Detection Logic
2
o I C Control Interface
Ordering Information
PART
TEMP RANGE
-40°C to +85°C
-40°C to +105°C
PIN-PACKAGE
40 TQFN-EP*
40 TQFN-EP*
MAX9856ETL+
MAX9856GTL/V+
+Denotes a lead-free/RoHS-compliant package.
*EP = Exposed pad.
/V denotes an automotive qualified part.
The MAX9856 supports all common sample rates from
8kHz to 48kHz in both master and slave mode. The ser-
ial digital audio interfaces support a variety of formats
2
including I S, left-justified, and PCM modes.
Simplified Block Diagram
The MAX9856 uses a thermally efficient, space-saving
40-pin, 6mm x 6mm x 0.8mm TQFN package.
DVDD AND DVDDS2
1.71V TO 3.6V
AVDD AND CPVDD
1.71V TO 3.6V
Applications
MAX9856
MP3 Players
Personal Media Players
Handheld Gaming Consoles
Cellular Phones
DAC
AUXIN
LINEIN1
LINEIN2
DIGITAL
FILTERING
AND
MUX
LEFT LINE
OUT
DAC
ADC
ADC
ANALOG
MIXERS
MIXERS
SDOUT
SDIN
BCLK
LRCLK_D
LRCLK_A
RIGHT LINE
OUT
DIGITAL
INTERFACE
DIFF
MIC
Pin Configuration appears at end of data sheet.
LEFT
EXT
MIC
SDA
SCL
IRQ
2
I C
CLOCK
CONTROL
RIGHT
EXT
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
MIC
MCLK
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.