General Description
The MAX4079 filters and buffers video (NTSC/PAL/DVB)
and stereo audio signals from the MPEG decoder of a
cable/satellite receiver, VCR/DVD player, or a TV to an
external load. The MAX4079 has luma-chroma (Y-C)
and composite (CVBS) video inputs with one Y-C and
two CVBS outputs. All video inputs are AC-coupled with
internal DC biasing on the chroma input and active
clamps for the luma and composite.
The MAX4079 video reconstruction filters have a 6MHz
cutoff frequency and 50dB attenuation at 27MHz. The
filters are matched with flat group delay for standard-
definition video. The video gain is fixed at +6dB to drive
a 75Ωback-terminated load (150Ω) to unity gain. The
video outputs can be either DC- or AC-coupled and are
powered by a single +5V supply.
The MAX4079 audio amplifiers have differential inputs
for optimum performance, but can be used with single-
ended sources with external biasing. The audio chan-
nels have a fixed gain of +6dB and deliver 2.6VRMS
output with a differential input of ±1.85V. The audio
amplifiers operate from a +9V to +12V single supply
and feature an internal bias generator. An on-chip
mixer also provides a mono output, with +3dB gain,
derived from the left and right audio channels.
The MAX4079 is available in 24-pin TSSOP package,
and is fully specified over the 0°C to +70°C commercial
temperature range. The MAX4079 Evaluation Kit is
available to help speed designs.
Applications
Satellite Receivers
Cable Receivers
Home Theater Systems
DVD Players
AV Receivers
Televisions
Features
♦Integrated Video Reconstruction Filters—6MHz
Lowpass Filter Supports NTSC, PAL, or DVB per
ITU-601
♦Integrated Video and Audio Amplifiers
♦Integrated Video Input Clamps and Biasing
♦Mono Audio and CVBS Output to Drive External
Modulator
♦+5V (Video) and +9V to +12V (Audio) Single-
Supply Operation
♦Differential/Single-Ended Audio Inputs
♦24-Pin TSSOP Package
MAX4079
Complete Audio/Video
Backend Solution
________________________________________________________________
Maxim Integrated Products
1
Ordering Information
19-3780; Rev 1; 3/09
EVALUATION KIT
AVAILABLE
PART TEMP RANGE PIN-PACKAGE
MAX4079CUG+ 0°C to +70°C 24 TSSOP
+
Denotes lead(Pb)-free package.
Functional Diagram
LP
FILTER
CLAMP
BIAS
NETWORK
CLAMP
RINP
RINN
LINP
LINN
CIN
CVBSIN
YIN
COUT
CVBSOUT1
CVBSOUT2
ROUT1
ROUT2
MONO
LOUT1
LOUT2
GVID
GAUD
VVID
AUDV REXT
CBYPASS
+3dB
+6dB
+6dB
+6dB
+6dB
+6dB
+6dB
+6dB
+6dB YOUT
LP
FILTER
LP
FILTER
MAX4079
Pin Configuration appears at end of data sheet.
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.
MAX4079
Complete Audio/Video
Backend Solution
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
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.
GVID to GAUD.......................................................-0.1V to +0.1V
VVID to GVID ............................................................-0.3V to +6V
AUDV to GAUD ......................................................-0.3V to +14V
LINP, LINN, RINP, RINN, CBYPASS to GAUD .........-0.3V to +6V
LOUT1, LOUT2, ROUT1, ROUT2,
MONO to GAUD ......-0.3V to lower of (+9V and AUDV + 0.3V)
YIN, CIN, CVBSIN, REXT to GVID.............-0.3V to (VVID + 0.3V)
YOUT, COUT, CVBSOUT1, CVBSOUT2 to
GVID.......................................................-0.3V to (VVID + 0.3V)
Video Output Short-Circuit Duration to GVID or
VVID ........................................................................Continuous
Audio Output Short-Circuit Duration to GAUD or
AUDV.......................................................................Continuous
Continuous Power Dissipation (TA= +70°C)
24-Pin TSSOP (derate 12.2mW/°C above +70°C) .....975.6mW
Operating Temperature Range...............................0°C to +70°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
DC ELECTRICAL CHARACTERISTICS
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RLOAD_VID = 150Ωto GVID, RREXT = 10kΩ±1%, CCBYPASS = 1µF, TA= 0°C to
+70°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SUPPLIES
Audio Supply Voltage Range AUDV 8.5 12.6 V
Video Supply Voltage Range VVID 4.75 5.0 5.25 V
Video Quiescent Supply Current ICCV VVVID = 5.25V, no load, all video inputs
AC-coupled to ground 60 100 mA
Audio Quiescent Supply Current ICCA VAUDV = 12.6V, no load, audio inputs
biased at 2.5V 815mA
Thermal Shutdown TSD Rising die temperature +150 °C
Thermal-Shutdown Hysteresis TSD
,
HYS 25 °C
VIDEO
Voltage Gain AV,VID VIN = 1VP-P, all video inputs, no load 5.8 6 6.2 dB
Gain Matching ΔAV
,
VID VIN = 1VP-P, all video inputs, no load -0.4 +0.4 dB
YIN, CVBSIN 0 1.2
Input Voltage Swing VIN,VID CIN 0 0.9 VP-P
Clamp Voltage VCLMP CVBSOUT_ and YOUT, no signal, no load 1.0 V
Chroma Bias VBIAS COUT, no signal, no load 2.1 V
Droop D (Note 2) 2 %
REXT Reference Voltage VREXT 0.85 1.00 1.15 V
CVBSIN or YIN 2.3 MΩ
Input Resistance RIN,VID CIN 10 kΩ
Input Clamping Current ICLMP CVBSIN or YIN input, VIN = 3.5V 1 2.5 4 µA
CVBSOUT_, YOUT 2.4
Output Voltage Swing VOUT
,
VID COUT 1.8 VP-P
Short-Circuit Current ISC,VID Video output shorted to VVID or GVID 50 mA
YOUT/COUT 48
Power-Supply Rejection Ratio PSRRVID 4.75V ≤ VVVID ≤
5.25V CVBSOUT_ 48 dB
MAX4079
Complete Audio/Video
Backend Solution
_______________________________________________________________________________________ 3
DC ELECTRICAL CHARACTERISTICS (continued)
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RLOAD_VID = 150Ωto GVID, RREXT = 10kΩ±1%, CCBYPASS = 1µF, TA= 0°C to
+70°C, unless otherwise noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
AUDIO
Voltage Gain AV,AUD 1.414VP-P differential input 5.8 6 6.2 dB
Mono Voltage Gain AV
,
MONO 1.414VP-P differential input, LIN = RIN 2.8 3 3.2 dB
Gain Matching Between
Channels ΔAV
,
AUD 1.414VP-P differential input -0.4 +0.4 dB
Input Voltage Range VIN
,
AUD Inferred from CMRR test 0.3 5.2 V
Differential Input Voltage Range VIN
,
AUD DIF Inferred from output voltage swing -1.85 +1.85 V
Input Current IIN,AUD 2µA
Output Voltage Swing VOUT
,
AUD Input overdriven, 10kΩ load to 4.15V 7.4 VP-P
Short-Circuit Current ISC
,
AUD 15 mA
Power-Supply Rejection Ratio PSRRAUD 8.5V ≤ VAUDV ≤ 12.6V 70 dB
Common-Mode Rejection Ratio CMRRAUD 0.3V ≤ VCM ≤ 5.2V 50 60 dB
AC ELECTRICAL CHARACTERISTICS
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩ±1% to GAUD, RREXT = 10kΩ, CCBYPASS = 1µF, TA= 0°C to +70°C, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
VIDEO
f = 4MHz -0.5 +0.5
f = 7MHz 3
Filter Attenuation AVIDEO
CVBSOUT1 = CVBSOUT2 =
YOUT = COUT = 2VP-P;
RL = 150Ω to ground,
attenuation is referred to
100kHz f = 27MHz 40 50
dB
Slew Rate SR VOUT = 2VP-P 30 V/µs
Differential Gain DG CVBSOUT_, YOUT, COUT, 5-step
modulated staircase 0.5 %
Differential Phase DP CVBSOUT_, YOUT, COUT, 5-step
modulated staircase 0.9 degrees
YOUT/COUT 48
Power-Supply Rejection Ratio PSRRVID f = 100kHz, 0.5VP-P CVBSOUT_ 44 dB
Peak Signal to RMS Noise SNRVID CVBSOUT_, YOUT, COUT, VIN = 1VP-P 65 dB
Group Delay Deviation GD CVBSOUT_, YOUT, COUT, fIN = 0.1MHz to
4.5MHz 25 ns
Output Impedance ZOUT,VID f = 3.58MHz 0.5 Ω
Capacitive Load CL,VID No sustained oscillations 35 pF
Video Crosstalk XTALK,VID f = 3.58MHz, 1VP-P input, between any two
active inputs -63
Audio/Video Crosstalk XTALK
,
VD/AD f = 15kHz, 1VP-P input, between any two
active audio or video inputs -76
dB
MAX4079
Complete Audio/Video
Backend Solution
4 _______________________________________________________________________________________
AC ELECTRICAL CHARACTERISTICS (continued)
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩ±1% to GAUD, RREXT = 10kΩ, CCBYPASS = 1µF, TA= 0°C to +70°C, unless otherwise
noted. Typical values are at TA= +25°C.) (Note 1)
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
AUDIO
LOUT_, ROUT_, fIN = 20Hz to 20kHz,
0.5VRMS input 0.01
Gain Flatness ΔAAUD MONO, fIN = 20Hz to 20kHz, 0.5VRMS
input 0.01
dB
Signal-to-Noise Ratio SNRAUD
fIN = 1.0kHz, 0.5VRMS, CCIR weighing
highpass filter at 20Hz, lowpass filter at
20kHz
85 dB
fIN = 1.0kHz, 0.5VRMS 0.005
Total Harmonic Distortion
Plus Noise THD+N fIN = 1.0kHz, 1VRMS 0.003 %
Output Impedance ZO,AUD f = 1kHz 0.2 Ω
Power-Supply Rejection Ratio PSRRAUD
,
AC f = 1kHz, VRIPPLE = 200mVP-P 60 dB
Crosstalk XTLK,AUD f = 1kHz, 0.5VRMS input 70 dB
Capacitive Load CL,AUD No sustained oscillations 200 pF
Note 1: All devices are 100% production tested at TA= +25°C. Specifications over temperature limits are guaranteed by design.
Note 2: Droop is defined as the percentage change in the DC level from the start to the end of a video line. Inferred from input
clamping current with a 0.1µF coupling capacitor.
CHROMA LARGE-SIGNAL BANDWIDTH
MAX4079 toc01
FREQUENCY (MHz)
RESPONSE (dB)
101
-70
-60
-50
-40
-30
-20
-10
0
10
-80
0.1 100
VIN = 1VP-P
LUMA LARGE-SIGNAL BANDWIDTH
MAX4079 toc02
FREQUENCY (MHz)
RESPONSE (dB)
101
-70
-60
-50
-40
-30
-20
-10
0
10
-80
0.1 100
VIN = 1VP-P
CVBSOUT_ LARGE-SIGNAL BANDWIDTH
MAX4079 toc03
FREQUENCY (MHz)
RESPONSE (dB)
101
-70
-60
-50
-40
-30
-20
-10
0
10
-80
0.1 100
VIN = 1VP-P
Typical Operating Characteristics
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩto GAUD, RREXT = 10kΩ, CBYPASS = 1µF, TA= +25°C, unless otherwise noted.)
MAX4079
Complete Audio/Video
Backend Solution
_______________________________________________________________________________________
5
VIDEO CROSSTALK (CVBSOUT_ TO YIN)
MAX4079 toc04
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
VIDEO CROSSTALK (CVBSOUT_ TO CIN)
MAX4079 toc05
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
VIDEO CROSSTALK (COUT TO CVBSIN)
MAX4079 toc06
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
VIDEO CROSSTALK (COUT TO YIN)
MAX4079 toc07
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
VIDEO CROSSTALK (YOUT TO CVBSIN)
MAX4079 toc08
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
VIDEO CROSSTALK (YOUT TO CIN)
MAX4079 toc09
FREQUENCY (MHz)
RESPONSE (dB)
101
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.1 100
VIN = 1VP-P
CVBSOUT_ GROUP DELAY
MAX4079 toc10
FREQUENCY (MHz)
DELAY (ns)
1
10
20
30
40
50
60
70
80
90
100
0
0.1 10
CHROMA GROUP DELAY
MAX4079 toc11
FREQUENCY (MHz)
DELAY (ns)
1
10
20
30
40
50
60
70
80
90
100
0
0.1 10
YOUT GROUP DELAY
MAX4079 toc12
FREQUENCY (MHz)
DELAY (ns)
1
10
20
30
40
50
60
70
80
90
100
0
0.1 10
Typical Operating Characteristics (continued)
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩto GAUD, RREXT = 10kΩ, CBYPASS = 1µF, TA= +25°C, unless otherwise noted.)
MAX4079
Complete Audio/Video
Backend Solution
6 _______________________________________________________________________________________
Typical Operating Characteristics (continued)
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩto GAUD, RREXT = 10kΩ, CBYPASS = 1µF, TA= +25°C, unless otherwise noted.)
DIFFERENTIAL GAIN
MAX4079 toc13
DIFFERENTIAL PHASE (deg)
13245
67
13245
67
0.2
0.1
0
-0.1
-0.2
DIFFERENTIAL GAIN (%)
0.2
0.1
0
-0.1
-0.2
DIFFERENTIAL PHASE
AUDIO LARGE-SIGNAL BANDWIDTH
MAX4079 toc14
FREQUENCY (kHz)
RESPONSE (dB)
1010.1
2.8
2.9
3.0
3.1
3.2
3.3
2.7
0.01 100
MONO CHANNEL
VIN = 0.5VRMS
AUDIO LARGE-SIGNAL BANDWIDTH
MAX4079 toc15
FREQUENCY (kHz)
RESPONSE (dB)
1010.1
5.5
6.0
6.5
7.0
5.0
0.01 100
RIGHT CHANNEL
VIN = 0.5VRMS
AUDIO LARGE-SIGNAL BANDWIDTH
MAX4079 toc16
FREQUENCY (kHz)
RESPONSE (dB)
1010.1
5.5
6.0
6.5
7.0
5.0
0.01 100
LEFT CHANNEL
VIN = 0.5VRMS
AUDIO CROSSTALK
MAX4079 toc17
FREQUENCY (kHz)
RESPONSE (dB)
1010.1
-110
-100
-90
-80
-70
-60
-50
-40
-120
0.01 100
LEFT TO RIGHT CHANNEL
RIGHT TO LEFT CHANNEL
VIN = 0.5VRMS
TOTAL HARMONIC DISTORTION
PLUS NOISE RATIO (LEFT CHANNEL)
MAX4079 toc18
FREQUENCY (kHz)
THD+N (%)
1010.1
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0.010
0.001
0.01 100
VIN = 1VRMS
VIN = 0.5VRMS
Typical Operating Characteristics (continued)
(VVVID = +5V, VAUDV = +12V, VGVID = VGAUD = 0V, RIN_VIDEO = 75Ωto GVID, CIN_VIDEO = 0.1µF, RLOAD_VID = 150Ωto GVID,
COUT_AUDIO = 10µF, RLOAD_AUD = 10kΩto GAUD, RREXT = 10kΩ, CBYPASS = 1µF, TA= +25°C, unless otherwise noted.)
MAX4079
Complete Audio/Video
Backend Solution
_______________________________________________________________________________________
7
2.0
2.9
2.6
2.3
3.2
3.5
0 10203040506070
INPUT CLAMP CURRENT
vs. TEMPERATURE
MAX4079 toc22
TEMPERATURE (°C)
INPUT CLAMP CURRENT (μA)
YIN
CVBSIN
VIN = 3.5V
INPUT CLAMP CURRENT
vs. INPUT VOLTAGE
MAX4079 toc23
INPUT VOLTAGE (V)
INPUT CLAMP CURRENT (μA)
4.54.03.53.02.52.01.51.00.5
10
100
1000
10,000
1
0 5.0
CVBSIN
YIN
SINKING
SOURCING
0.7
0.8
1.0
0.9
1.1
1.2
1.3
02010 30 40 50 60 70
OUTPUT BIAS VOLTAGE
vs. TEMPERATURE
MAX4079 toc24
TEMPERATURE (°C)
OUTPUT BIAS VOLTAGE (V)
CVBSOUT_
YOUT
1.5
1.7
2.1
1.9
2.3
2.5
02010 30 40 50 60 70
OUTPUT BIAS VOLTAGE
vs. TEMPERATURE
MAX4079 toc25
TEMPERATURE (°C)
OUTPUT BIAS VOLTAGE (V)
COUT
55
58
57
56
60
59
64
63
62
61
65
0 10203040506070
VIDEO SUPPLY CURRENT
vs. TEMPERATURE
MAX4079 toc20
TEMPERATURE (°C)
VIDEO SUPPLY CURRENT (mA)
5.0
6.0
5.5
7.0
6.5
8.5
8.0
7.5
9.0
02010 30 40 50 60 70
AUDIO SUPPLY CURRENT
vs. TEMPERATURE
MAX4079 toc21
TEMPERATURE (°C)
AUDIO SUPPLY CURRENT (mA)
TOTAL HARMONIC DISTORTION
PLUS NOISE RATIO (RIGHT CHANNEL)
MAX4079 toc19
FREQUENCY (kHz)
THD+N (%)
1010.1
0.002
0.003
0.004
0.005
0.006
0.007
0.008
0.009
0.010
0.001
0.01 100
VIN = 1VRMS
VIN = 0.5VRMS
MAX4079
Detailed Description
The MAX4079 filters and buffers video (NTSC/PAL/DVB)
and stereo audio signals from the MPEG decoder of a
cable/satellite receiver, VCR/DVD player, or a TV to an
external load. The MAX4079 has luma-chroma (Y-C)
and composite (CVBS) video inputs with one Y-C and
two CVBS outputs. All video inputs are AC-coupled with
internal DC biasing on the chroma input and active
clamps for the luma and composite.
The MAX4079 video reconstruction filters have a 6MHz
cutoff frequency and 50dB attenuation at 27MHz. The
filters are matched, with flat group delay for standard-
definition video. The video gain is fixed at +6dB to drive
a 75Ωback-terminated load (150Ω) to unity gain. The
video outputs can be either DC- or AC-coupled and are
powered by a single +5V supply.
The MAX4079 audio amplifiers have differential inputs
for optimum performance, but can be used with single-
ended sources with external biasing. The audio chan-
nels have a fixed gain of +6dB and deliver 2.6VRMS
output with a differential input of ±1.85V. The audio
amplifiers operate from a +9V to +12V single supply
and feature an internal bias generator. An on-chip
mixer also provides a mono output, with +3dB gain,
derived from the left and right audio channels.
Video
The video section of the MAX4079 implements DC
restore/biasing, amplification, and reconstruction filter-
ing for the Y-C and CVBS input signals. All of the video
inputs are AC-coupled. DC restore is performed using
a sync tip clamp for both luma and composite video
channels. The chroma DC level input is biased at the
midlevel of the signal.
All video channels have a fixed gain of +6dB. The DC
level at the video outputs is controlled so that coupling
capacitors are not required.
All composite and luma video outputs are capable of
driving 2.4VP-P, and the chroma output is capable of
driving 1.8VP-P into 150Ωresistive load to ground. Up
to 35pF of load capacitance can be tolerated at each
video output without stability or slew-rate issues.
Complete Audio/Video
Backend Solution
8 _______________________________________________________________________________________
Pin Description
PIN NAME FUNCTION
1 REXT External Filter Resistor. Bypass with a 10kΩ ±1% resistor and a 0.1µF capacitor to GVID.
2, 24 VVID Video Power-Supply Input
3 CVBSIN Composite Video Input
4, 21 GVID Video Ground
5 YIN Luma Input
6 CBYPASS Audio LDO Regulator Bypass Capacitor. Bypass with a1µF capacitor to GAUD.
7 CIN Chroma Input
8 AUDV Audio Power-Supply Input
9 LINP Left-Channel Audio Positive Input
10 LINN Left-Channel Audio Negative Input
11 RINN Right-Channel Audio Negative Input
12 RINP Right-Channel Audio Positive Input
13 ROUT2 Right-Channel Audio Output 2
14 ROUT1 Right-Channel Audio Output 1
15 GAUD Audio Ground
16 MONO Mono Audio Output
17 LOUT2 Left-Channel Audio Output 2
18 LOUT1 Left-Channel Audio Output 1
19 COUT Chroma Video Output
20 YOUT Luma Video Output
22 CVBSOUT1 Composite Video Output 1
23 CVBSOUT2 Composite Video Output 2
All video inputs are stable with up to 150Ωsource resis-
tance. For higher values, consult Maxim applications.
Video Reconstruction Filter
The MAX4079 reconstruction filters are 4th-order
Butterworth filters that provide a cutoff frequency of
6MHz and flat group delay response up to 4.5MHz. The
stopband offers 26dB of attenuation at 13.5MHz and
50dB at 27MHz.
Audio
The audio section of the MAX4079 is a stereo amplifier
with one differential input and two single-ended outputs
for each channel (left and right). A mono output is pro-
vided by summing the two channels of the stereo signal
together. The stereo channels have a +6dB typical
gain, while the mono has a +3dB gain.
The audio inputs can be DC-coupled, eliminating space-
consuming coupling capacitors. Each of the five outputs
can deliver 2.6VRMS into an AC-coupled 10kΩload.
Applications Information
Audio DAC Interfacing
Differential Audio DAC
The MAX4079 accepts differential audio signals. Figure
1 shows a typical configuration for connecting the
device to an audio DAC with differential outputs. Figure
2 shows the reconstruction filters that can be used for
the differential audio inputs. Carefully select resistors
and capacitors to attenuate out-of-band noise and mini-
mize the effect on the gain. The common-mode voltage
for these signals is typically 2.5V.
Single-Ended Audio DAC
The MAX4079 can also be configured for single-ended
inputs. Figure 3 shows how to connect an audio DAC with
single-ended outputs to the MAX4079. Figure 4 shows
how reconstruction filters can be used for single-ended
audio inputs. Choose these values to minimize the
effect on gain.
If the single-ended audio DAC does not include a com-
mon-mode voltage output, create a bias point with well-
matched resistors and couple the audio signal to the
positive differential input (see Figure 5). The bias point
can also be created using a resistor-divider network
from the video supply voltage. Note that the tolerance of
the resistors will affect the common-mode and power-
supply rejection ratios. Tighter tolerances improve the per-
formance of CMRR and PSRR, e.g., 1% resistors will not
give any better than 40dB of CMRR and PSRR, whereas
0.1% resistors could improve the number to 60dB.
Power Supplies and Bypassing
The MAX4079 features single +5V (video) and +12V
(audio) supply operation, and requires no negative
supply. Connect the VVID pins together and bypass to
GVID with 0.01µF, 0.1µF, and 4.7µF capacitors in paral-
lel. Bypass the AUDV to GAUD with 0.1µF, 1µF, and
47µF capacitors in parallel. Bypass CBYPASS to GAUD
with a 1µF capacitor (see the
Typical Operating Circuit
).
MAX4079
Complete Audio/Video
Backend Solution
_______________________________________________________________________________________ 9
RINP
RINN
LINP
LINN
LEFT AUDIO
CHANNEL
RIGHT AUDIO
CHANNEL
+5V
AOUTL+
AOUTL-
AOUTR+
AOUTR-
AUDIO
DAC
MAX4079
Figure 1. Differential Audio Inputs
MAX4079
R2
C2
R2
AOUTL+
AOUTL-
LINP
LINN
R1
R1
C1
C2
Figure 2. Filtering Differential Audio Inputs
MAX4079
Complete Audio/Video
Backend Solution
10 ______________________________________________________________________________________
RINP
RINN
LINP
LINN
LEFT AUDIO
CHANNEL
RIGHT AUDIO
CHANNEL
+5V
AOUTL
AOUTR
AUDIO
DAC
MAX4079
~2.5V
VCM
Figure 3. Single-Ended Audio Inputs
MAX4079
R1
C1
R1
AOUTL
VCM
LINP
LINN
Figure 4. Filtering Single-Ended Audio Inputs
RINP
RINN
LINP
LINN
LEFT AUDIO
CHANNEL
RIGHT AUDIO
CHANNEL
MAX4079
RR
RR
RR
RR
AOUTL
AOUTR
VBIAS
VBIAS
Figure 5. Biasing Single-Ended Audio Inputs
40μs/div
INPUT
OUTPUT
Figure 6. Vertical Sync Interval
Layout and Grounding
For optimal performance, stitch ground vias between the
narrow adjacent signal traces to minimize crosstalk.
Avoid running video traces parallel to high-speed data
lines. The MAX4079 provides separate ground connections
for video and audio supplies. For best performance use
separate ground planes for each of the ground returns,
and connect all ground planes together at a single point.
Refer to the MAX4079 Evaluation Kit for a proven circuit
board layout example.
MAX4079
Complete Audio/Video
Backend Solution
______________________________________________________________________________________ 11
1μF
10kΩ
10kΩ
10kΩ
10μF
10μF
10μF
10μF
10μF10kΩ
10kΩ
75Ω
75Ω
75Ω
75Ω
Z0 = 75Ω
Z0 = 75Ω
Z0 = 75Ω
Z0 = 75Ω
330μF
330μF
330μF
330μF
0.1μF1μF47μF
+12V AUDIO SUPPLY
0.01μF
0.1μF
4.7μF
+5V VIDEO SUPPLY
0.1μF
0.1μF
0.1μF
75Ω
75Ω
75Ω
RINP
RINN
LINP
LINN
0.1μF
10kΩ
75Ω
75Ω
75Ω
75Ω
AUDV
GAUD
YOUT
COUT
CVBSOUT1
CVBSOUT2
ROUT1
ROUT2
MONO
LOUT1
CBYPASS
LOUT2
*OPTIONAL CAPACITORS
(TYPICAL VALUES SHOWN)
VVID
VVID
GVID
GVID
YIN
YIN
CINCIN
CVBSINCVBSIN
RINP
RINN
LINP
LINN
REXT
MAX4079
Typical Operating Circuit
MAX4079
Complete Audio/Video
Backend Solution
12 ______________________________________________________________________________________
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
VVID
CVBSOUT2
CVBSOUT1
GVIDGVID
CVBSIN
VVID
REXT
TOP VIEW
YOUT
COUT
LOUT1
LOUT2AUDV
CIN
CBYPASS
YIN
16
15
14
13
9
10
11
12
MONO
GAUD
ROUT1
ROUT2RINP
RINN
LINN
LINP
TSSOP
MAX4079
+
Pin Configuration Chip Information
PROCESS: BiCMOS
MAX4079
Complete Audio/Video
Backend Solution
______________________________________________________________________________________ 13
MAX4079
TSSOP4.40mm.EPS
PACKAGE TYPE PACKAGE CODE DOCUMENT NO.
24 TSSOP U24+1 21-0066
Package Information
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
MAX4079
Complete Audio/Video
Backend Solution
14 ______________________________________________________________________________________
SOICW.EPS
PACKAGE OUTLINE, .300" SOIC
1
1
21-0042 B
REV.DOCUMENT CONTROL NO.APPROVAL
PROPRIETARY INFORMATION
TITLE:
TOP VIEW
FRONT VIEW
MAX
0.012
0.104
0.019
0.299
0.013
INCHES
0.291
0.009
E
C
DIM
0.014
0.004
B
A1
MIN
0.093A
0.23
7.40 7.60
0.32
MILLIMETERS
0.10
0.35
2.35
MIN
0.49
0.30
MAX
2.65
0.050
0.016L0.40 1.27
0.5120.496D
D
MINDIM
D
INCHES
MAX
12.60 13.00
MILLIMETERS
MIN MAX
20 AC
0.447 0.463 AB11.7511.35 18
0.398 0.413 AA10.5010.10 16
N MS013
SIDE VIEW
H 0.4190.394 10.00 10.65
e 0.050 1.27
D 0.6140.598 15.20 2415.60 AD
D 0.7130.697 17.70 2818.10 AE
H
E
N
D
A1
B
e
A
0∞-8∞
C
L
1
VARIATIONS:
Package Information (continued)
For the latest package outline information and land patterns, go to www.maxim-ic.com/packages.
MAX4079
Complete Audio/Video
Backend Solution
Heaney
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________
15
© 2009 Maxim Integrated Products Maxim is a registered trademark of Maxim Integrated Products, Inc.
Revision History
REVISION
NUMBER
REVISION
DATE DESCRIPTION PAGES
CHANGED
0 8/05 Initial release —
1 3/09 Changes to remove SO package, style edits 1–7, 12, 13, 14
