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MAX9850
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 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 feature saves board space,
provides higher click/pop suppression, 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 conventional, 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 left-justified, rightjustified audio data, 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 headphone
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 lowprofile, 28-pin thin QFN package (5mm x 5mm x 0.8mm).
Applications
● MP3/Portable Multimedia Players
● Cell Phones/Smart Phones
● Portable DVD Players
Stereo Audio DAC with DirectDrive
Headphone Amplifier
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
TEMP RANGE
PINPACKAGE
PKG
CODE
MAX9850ETI+
-40°C to +85°C
28 TQFN-EP**
T2855+
**EP = Exposed pad.
+Denotes lead-free package.
Pin Configuration appears at end of data sheet.
Block Diagram
MCLK
1.8V TO 3.6V
INR
DIGITAL
PLL
OUTR
MAX9850
HPR
DAC
SDIN
BCLK
LRCLK
DIGITAL
AUDIO
SDA
SCL
ADD
GPIO
I 2C
HPL
DAC
OUTL
INL
19-3454; Rev 4; 8/19
LINE
OUT
LINE
OUT
MAX9850
Stereo Audio DAC with DirectDrive
Headphone Amplifier
Absolute Maximum Ratings
(Voltages with respect to AGND.)
DVDD, AVDD, PVDD.................................................-0.3V to +4V
AVDD Referenced to PVDD...................................-0.3V to +0.3V
SVSS, PVSS.............................................................-4V to +0.3V
SVSS Referenced to PVSS....................................-0.3V to +0.3V
DGND, PGND.......................................................-0.3V to +0.3V
BCLK, LRCLK, HPS, SDIN.....................-0.3V to (DVDD + 0.3V)
GPIO, MCLK............................................................-0.3V to +4V
REF, PREG............................................. -0.3V to (AVDD + 0.3V)
NREG...................................................... +0.3V to (SVSS - 0.3V)
SDA, SCL, ADD.......................................................-0.3V to +4V
INL, INR.......................................................................-2V to +2V
HPR, HPL.................................. (SVSS - 0.3V) to (AVDD + 0.3V)
OUTL, OUTR........................... (NREG - 0.3V) to (PREG + 0.3V)
C1N.......................................... (PVSS - 0.3V) to (PGND + 0.3V)
C1P...........................................(PGND - 0.3V) to (PVDD + 0.3V)
Current Into/Out of Any Pin...............................................100mA
Duration of HPL, HPR, OUTL,
OUTR Short Circuit to AGND.................................Continuous
Continuous Power Dissipation (TA = +70°C)
28-Pin Thin QFN (derate 35.7mW/°C above +70°C)....2857mW
Junction Temperature.......................................................+150°C
Operating Temperature Range............................ -40°C to +85°C
Storage Temperature Range............................. -65°C to +150°C
Lead Temperature (soldering, 10s).................................. +300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these
or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Electrical Characteristics
(DVDD = AVDD = PVDD = 3.0V, AGND = DGND = PGND = 0V, C1 = 0.47μF, C2 = 2.2μF, CNREG = CPREG = CREF = 1μF to AGND,
RLOAD_HP = 32Ω to AGND, RLOAD_OUT = 10kΩ to AGND, fLRCLK = 48kHz, fMCLK = 12.288MHz, volume set to -9.5dB, TA = TMIN to
TMAX, unless otherwise noted. Typical specifications at TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
Analog Supply Voltage
AVDD,
PVDD
Digital Supply Voltage
DVDD
Analog Supply Current
Digital Supply Current
AIDD
DIDD
CONDITIONS
MIN
AVDD = PVDD
TYP
MAX
UNITS
1.8
3.6
V
1.8
3.6
V
Full operation (Note 2), no
headphone or line output load
AVDD = 1.8V
5.5
AVDD = 3.0V
5.9
Full operation (Note 2),
headphones disabled
AVDD = 1.8V
3.5
AVDD = 3.0V
3.75
Full operation (Note 2),
no line output load
DVDD = 1.8V
2.1
DVDD = 3.0V
3.8
7.7
5.3
2.9
mA
mA
Analog Shutdown Current
AISHDN
IAVDD + IPVDD, AVDD = PVDD = 1.8V
1.5
10
µA
Digital Shutdown Current
DISHDN
Static digital interface, DVDD = 1.8V
0.3
5
µA
Shutdown to Full Operation
(Note 2)
tON
1.3
ms
Power-On to Full Operation
(Note 2)
tPON
1.4
ms
DAC PERFORMANCE/LINE OUTPUTS (Note 3)
0dBFS Output Voltage
Dynamic Range (Note 4)
Signal-to-Noise Ratio
(Note 5)
www.maximintegrated.com
VOUT_FS
DR
SNR
1.85
AVDD = 3.0V
AVDD = 1.8V
1.95
87.5
82
87.5
Unweighted
88
A-weighted
91
AVDD = 1.8V, unweighted
88
AVDD = 1.8V, A-weighted
91
2.05
VP-P
dB
dB
Maxim Integrated │ 2
MAX9850
Stereo Audio DAC with DirectDrive
Headphone Amplifier
Electrical Characteristics (continued)
(DVDD = AVDD = PVDD = 3.0V, AGND = DGND = PGND = 0V, C1 = 0.47μF, C2 = 2.2μF, CNREG = CPREG = CREF = 1μF to AGND,
RLOAD_HP = 32Ω to AGND, RLOAD_OUT = 10kΩ to AGND, fLRCLK = 48kHz, fMCLK = 12.288MHz, volume set to -9.5dB, TA = TMIN to
TMAX, unless otherwise noted. Typical specifications at TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
0dBFS
Total Harmonic Distortion Plus
Noise
THD+N
Line Output Offset Voltage
VOS_LINE
Channel-to-Channel Gain
Matching
ΔAV/AV
Power-Supply Rejection Ratio
PSRR
Crosstalk
XTALK
Sampling Frequency Range
MCLK Frequency
fIN = 984.375Hz
TYP
MAX
UNITS
87
-60dBFS
27.5
AVDD = 1.8V,
0dBFS
-81
AVDD = 1.8V,
-60dBFS
-27.5
-22
0
+15
-15
OUTL to OUTR, OUTR to OUTL
dB
±0.04
VRIPPLE = 100mVP-P, fIN = 1kHz,
applied to AVDD and PVDD
87
VRIPPLE = 100mVP-P, fIN = 20kHz,
applied to AVDD and PVDD
67
mV
dB
dB
fOUT = 1kHz, VOUT = 2VP-P
(OUTL to OUTR) or (OUTR to OUTL)
-105
dB
fS
8
48
kHz
fMCLK
8.448
40
MHz
DAC 8x INTERPOLATION FILTER
Passband Frequency
PB
To -1dB corner
0
Frequency Response
FR
10Hz to 20kHz
-0.1
Stopband Attenuation
SBA
Stopband Frequency
SB
0.48 x fS
+0.1
58
Attenuation greater than SBA
kHz
dB
dB
0.58 x fS
7.42 x fS
kHz
LINE INPUTS (INL, INR)
Line Input Voltage
VIN_LINE
-1
IN_ to OUT_ Gain
AV_LINE
-1.05
VBIAS_LINE
RIN_LINE
Line Input Bias Voltage
INL and INR Input Resistance
+1
V
-1
-0.95
V/V
-15
0
+15
mV
10
22
kΩ
INTERNAL REGULATORS (NREG, PREG)
PREG Output Voltage
VPREG
1.60
V
NREG Output Voltage
VNREG
-1.15
V
VREF
1.23
V
REF Output Voltage
www.maximintegrated.com
Maxim Integrated │ 3
MAX9850
Stereo Audio DAC with DirectDrive
Headphone Amplifier
Electrical Characteristics (continued)
(DVDD = AVDD = PVDD = 3.0V, AGND = DGND = PGND = 0V, C1 = 0.47μF, C2 = 2.2μF, CNREG = CPREG = CREF = 1μF to AGND,
RLOAD_HP = 32Ω to AGND, RLOAD_OUT = 10kΩ to AGND, fLRCLK = 48kHz, fMCLK = 12.288MHz, volume set to -9.5dB, TA = TMIN to
TMAX, unless otherwise noted. Typical specifications at TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
HEADPHONE OUTPUTS (HPL, HPR)
RL = 16Ω
AVDD = 3.0V
Output Power
OUT
RL = 32Ω
AVDD = 3.0V
THD+N = 1%
fIN = 1kHz, headphone
volume = +6dB
40
65
mW
RL = 16Ω
AVDD = 1.8V
RL = 32Ω
AVDD = 1.8V
Full-Scale Headphone Amplifier
Output Voltage
95
30
15
25
VOUT_FS
Volume = +5dB, HP unloaded
1.16
1.23
1.30
VRMS
Line In to HP Output Voltage
Gain
AV_HP
Volume = +3dB, HP unloaded
1.34
1.41
1.48
V/V
Total Harmonic Distortion Plus
Noise
THD+N
Signal-to-Noise Ratio (Note 6)
Power-Supply Rejection Ratio
Headphone Output Offset
Voltage
SNR
PSRR
VOS_HP
Slew Rate
SR
Maximum Capacitive Load
CL
Crosstalk
XTALK
Channel-to-Channel Gain
Matching
ΔAV/AV
Internal Charge-Pump
Oscillator Frequency
Charge-Pump Operating
Frequency Range
Volume Control Range
www.maximintegrated.com
RL = 32Ω, POUT = 60mW, fIN = 1kHz
-94
RL = 16Ω, POUT = 60mW, fIN = 1kHz
-90
Unweighted
88
A-weighted
90
AVDD = 1.8V, unweighted
88
AVDD = 1.8V, A-weighted
91
VRIPPLE = 100mVP-P, frequency = 1kHz,
applied to AVDD and PVDD
91
VRIPPLE = 100mVP-P, frequency = 20kHz,
applied to AVDD and PVDD
72
Volume = -11.5dB
dB
dB
dB
TA = +25°C
-15
+15
TA = TMIN to TMAX
-25
+25
mV
0.47
V/µs
No sustained oscillations
150
pF
RHP = 32Ω, POUT = 3.5mW, fIN = 1kHz
(HPL to HPR) or (HPR to HPL)
-85
dB
±0.05
dB
fCP
550
Charge-pump clock derived from MCLK
667
775
kHz
550
775
kHz
-73.5
+6.0
dB
Maxim Integrated │ 4
MAX9850
Stereo Audio DAC with DirectDrive
Headphone Amplifier
Electrical Characteristics (continued)
(DVDD = AVDD = PVDD = 3.0V, AGND = DGND = PGND = 0V, C1 = 0.47μF, C2 = 2.2μF, CNREG = CPREG = CREF = 1μF to AGND,
RLOAD_HP = 32Ω to AGND, RLOAD_OUT = 10kΩ to AGND, fLRCLK = 48kHz, fMCLK = 12.288MHz, volume set to -9.5dB, TA = TMIN to
TMAX, unless otherwise noted. Typical specifications at TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
Mute Attenuation
TYP
MAX
100
UNITS
dB
DIGITAL INPUTS (GPIO, SCL, SDA, BCLK, LRCLK, SDIN, ADD, MCLK)
Input High Voltage
VIH
Input Low Voltage
VIL
Input Leakage Current
IIH, IIL
0.8 x
DVDD
VIH = DVDD, VIL = DGND
-10
Input Hysteresis
Input Capacitance
V
CIN
0.2 x
DVDD
V
+10
µA
0.09 x
DVDD
V
10
pF
OPEN-DRAIN DIGITAL OUTPUTS (GPIO, SDA)
Output-High Leakage Current
IOH
VOH = DVDD (Note 7)
Output Low Voltage
VOL
IOL = 3mA
1
DVDD > 2V
0.4
DVDD < 2V
0.2 x
DVDD
µA
V
CMOS DIGITAL OUTPUTS (BCLK, LRCLK)
Output High Voltage
VOH
IOH = 1mA
Output Low Voltage
VOL
IOL = 1mA
DVDD 0.4
V
0.4
V
HEADPHONE SENSE INPUT (HPS)
Input High Voltage
VIH
Input Low Voltage
VIL
Input-High Leakage Current
IIH
Input-Low Leakage Current
IIL
Input Hysteresis
www.maximintegrated.com
0.7 x
DVDD
V
0.25 x
DVDD
Full shutdown, VIH = DVDD
400
Normal operation, VIH = DVDD
1
Full shutdown, VIL = DGND
1
Normal operation, VIL = DGND
100
0.05 x
DVDD
V
µA
µA
V
Maxim Integrated │ 5
MAX9850
Stereo Audio DAC with DirectDrive
Headphone Amplifier
Electrical Characteristics (continued)
(DVDD = AVDD = PVDD = 3.0V, AGND = DGND = PGND = 0V, C1 = 0.47μF, C2 = 2.2μF, CNREG = CPREG = CREF = 1μF to AGND,
RLOAD_HP = 32Ω to AGND, RLOAD_OUT = 10kΩ to AGND, fLRCLK = 48kHz, fMCLK = 12.288MHz, volume set to -9.5dB, TA = TMIN to
TMAX, unless otherwise noted. Typical specifications at TA = +25°C, unless otherwise noted.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
400
kHz
I2C TIMING
Serial Clock Frequency
fSCL
0
Bus Free Time Between STOP
and START Conditions
tBUF
1.3
µs
Hold Time (Repeated) START
Condition
tHD, STA
0.6
µs
SCL Pulse-Width Low
tLOW
1.3
µs
SCL Pulse-Width High
tHIGH
0.6
µs
Repeated START Condition
Setup Time
tSU, STA
0.6
µs
Data Hold Time
tHD, DAT
0
Data Setup Time
tSU, DAT
100
Bus Capacitance
CB
SDA and SCL Receiving Rise
Time (Note 8)
tR
SDA and SCL Receiving Fall
Time (Note 8)
tF
SDA Transmitting Fall Time
(Note 8)
tF
900
ns
ns
400
pF
20 + 0.1CB
300
ns
20 + 0.1CB
300
ns
DVDD = 1.8V, TA = +25°C
20 + 0.1CB
250
DVDD = 3.6V, TA = +25°C
20 + 0.5CB
250
Setup Time for STOP Condition
tSU, STO
0.6
Pulse Width of Suppressed Spike
tSP
0
ns
µs
50
ns
DIGITAL AUDIO TIMING
BCLK Period (Note 9)
Low or High BCLK Pulse Width
tBCLK
tBCLK_PW
3 x 1/fICLK
ns
0.35 x tBCLK
ns
BCLK and LRCLK Rise Time
tR
Master mode, CLOAD = 15pF
1
ns
BCLK and LRCLK Fall Time
tF
Master mode, CLOAD = 15pF
1
ns
SDIN or LRCLK to BCLK Rising
Setup Time
tDBSU,
tBWSU
SDIN or LRCLK to BCLK Rising
Hold Time
tDBH,
tBWBH
30
ns
DVDD = 1.8V
0
DVDD = 3.6V
5
ns
Note 1: The MAX9850 is 100% production tested at TA = +25°C and is guaranteed by design for TA = TMIN to TMAX.
Note 2: Full operation is defined as clocking all zeros into the DAC while the DAC, headphone outputs, and line outputs are all
enabled.
Note 3: DAC performance specifications measured using the line outputs, OUTL and OUTR.
Note 4: Dynamic range is defined as the SNR of a 1kHz, -60dBFS input signal measured with an A-weighted filter, then normalized
to full scale (+60dB).
www.maximintegrated.com
Maxim Integrated │ 6
MAX9850
Note
Note
Note
Note
Note
5:
6:
7:
8:
9:
Stereo Audio DAC with DirectDrive
Headphone Amplifier
DAC SNR measured from DAC inputs to OUTL and OUTR.
Headphone amplifier SNR measured from line inputs to headphone outputs.
GPIO is 100kΩ to ground when DVDD < VOH < 3.6V.
CB is in pF.
fICLK derived by dividing fMCLK by 1, 2, 3, or 4. See the Registers and Bit Descriptions section.
Typical Power Dissipation at AVDD = 1.8V (No Headphone/Line Output Load)
MODE
AVDD POWER
DVDD POWER
PVDD POWER
TOTAL POWER
Full Operation (Note 1)
4.93mW
3.76mW
5.00mW
13.70mW
DAC to Line Outputs, Headphones Disabled
3.11mW
3.76mW
3.22mW
10.10mW
Line Inputs to Line Outputs and Headphone
Outputs, DAC Disabled
3.22mW
0.085mW
3.40mW
6.71mW
Line Inputs to Line Outputs, DAC and
Headphones Disabled
1.39mW
0.085mW
1.61mW
3.08mW
2.7µW
0.5µW
