19-3209; Rev 1; 2/09
KIT
ATION
EVALU
BLE
AVAILA
Low-Power Audio/Video Switch for
Dual SCART Connectors
General Description
The MAX9598 dual SCART matrix routes audio and video
signals between a set-top box decoder chip and two
external SCART connectors under I
2
C control. Operating
from a 3.3V supply and a 12V supply, the MAX9598 con-
sumes 70mW during quiescent operation and 471mW
during average operation when driving typical signals into
typical loads. Video input detection, video load detection,
and a 1.7mW low-power mode facilitate the design of low-
power set-top boxes.
The MAX9598 audio section contains a buffered cross-
point to route audio inputs to audio outputs. The
DirectDrive
®
output amplifiers create a 2V
RMS
full-scale
audio signal biased around ground, eliminating the
need for bulky output capacitors and reducing click-
and-pop noise. The zero-cross detection circuitry also
further reduces clicks and pops by enabling audio
sources to switch only during a zero-crossing.
The MAX9598 video section contains a buffered cross-
point to route video inputs to video outputs. The standard-
definition video signals from the set-top box decoder chip
are lowpass filtered to remove out-of-bandwidth artifacts.
The MAX9598 also supports slow-switching and fast-switch-
ing signals. An interrupt signal from the MAX9598 informs the
microcontroller (µC) when the system status has changed.
The MAX9598 is available in a compact 40-pin thin QFN
package and is specified over the 0°C to +70°C commer-
cial temperature range.
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
Features
♦
70mW Quiescent Power Consumption
♦
1.7mW Low-Power Mode Consumption
♦
0.1mW Shutdown Consumption
♦
Clickless/Popless, DirectDrive Audio
♦
Video Input Detection
♦
Video Load Detection
♦
Video Reconstruction Filter with 10MHz Passband
and 52dB Attenuation at 27MHz
♦
3.3V and 12V Supply Voltages
MAX9598
Applications
Set-Top Boxes
TVs
DVD Players
Ordering Information
PART
MAX9598CTL+
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
40 TQFN-EP*
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
System Block Diagram
V12
12V
STB CHIP
I
2
C
μC
INTERRUPT OUTPUT
VVID
3.3V
VAUD
3.3V
MAX9598
RGB, Y/C, CVBS
I
2
C INTERFACE AND
REGISTERS
CVBS
L/R AUDIO
TV
SCART
VIDEO
ENCODER
STEREO
AUDIO
DAC
RGB, Y/C, CVBS
VIDEO FILTERS AND
CROSSPOINT
AUDIO CROSSPOINT
WITH DirectDrive
OUTPUTS
SLOW SWITCHING
FAST SWITCHING
CHARGE PUMP
EP
GNDVID
SLOW SWITCHING
FAST SWITCHING
SINGLE-ENDED
STEREO AUDIO
Y/C, CVBS
RGB, Y/C, CVBS
L/R AUDIO
SLOW SWITCHING
FAST SWITCHING
VCR
SCART
________________________________________________________________
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.
Low-Power Audio/Video Switch for
Dual SCART Connectors
MAX9598
ABSOLUTE MAXIMUM RATINGS
VVID to GNDVID .......................................…………-0.3V to +4V
V12 to EP .................................................…………-0.3V to +14V
VAUD to EP ................................................…………-0.3V to +4V
EP to GNDVID .........................................…………-0.1V to +0.1V
All Video Inputs, VCRIN_FS to GNDVID ....…………-0.3V to +4V
All Audio Inputs to EP...........................…………-1V to (EP + 1V)
SDA, SCL, DEV_ADDR,
INT
to GNDVID ………… ...-0.3V to +4V
TV_SS, VCR_SS to EP ..................…………-0.3V to (V12 + 0.3V)
Current
All Video/Audio Inputs....................................…………±20mA
C1P, C1N, CPVSS ..........................................…………±50mA
Output Short-Circuit Current Duration
All Video Outputs, TVOUT_FS to VVID, GNDVID ...Continuous
Audio Outputs to VAUD, EP ...................................Continuous
TV_SS, VCR_SS to V12, EP ....................................Continuous
Continuous Power Dissipation (T
A
= +70°C)
40-Pin Thin QFN
(derate 26.3mW/°C above +70°C) ..........................2105.3mW
Operating Temperature Range ..............................0°C to +70°C
Junction Temperature .....................................................+150°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
(V12 = 12V, VVID = VAUD = 3.3V, V
GNDVID
= V
EP
= 0V, no load, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Video Supply Voltage Range
Audio Supply Voltage Range
V12 Supply Voltage Range
SYMBOL
VVID
VAUD
V12
CONDITIONS
Inferred from video PSRR test at 3V and
3.6V
Inferred from audio PSRR test at 3V and
3.6V
Inferred from slow-switching levels
Normal operation (Note 2), with all video
outputs enabled and muted
VVID Quiescent Supply Current
I
VID_Q
Low-power mode
Shutdown
VAUD Quiescent Supply Current
I
AUD_Q
Normal operation (Note 2)
Shutdown
POR state
V12 Quiescent Supply Current
I
12_Q
Normal operation
(Note 2)
Shutdown
VIDEO CHARACTERISTICS
DC-COUPLED INPUT
Input Voltage Range
Input Current
Input Resistance
AC-COUPLED INPUT
Sync-Tip Clamp Level
Sync Crush
V
CLP
Sync-tip clamp
Sync-tip clamp, percentage reduction in
sync pulse (0.3V
P-P
), guaranteed by input
clamping current measurement
-13
-3.5
+6
2
mV
%
V
IN
I
IN
R
IN
R
L
= 75Ω to GNDVID or
150Ω to VVID/2, inferred
from gain test
V
IN
= 0.3V
VVID = 3V
VVID = 3.135V
VVID = 3.3V
1.3
1
300
5
µA
kΩ
1.15
1.2
V
P-P
Slow-switching output
sets to medium level
MIN
3
3
11.4
TYP
3.3
3.3
12
18.2
500
18.4
2.7
12
3
475
0.25
10
MAX
3.6
3.6
12.6
30
1000
32
6
25
100
µA
UNITS
V
V
V
mA
µA
mA
µA
2
_______________________________________________________________________________________
Low-Power Audio/Video Switch for
Dual SCART Connectors
ELECTRICAL CHARACTERISTICS (continued)
(V12 = 12V, VVID = VAUD = 3.3V, V
GNDVID
= V
EP
= 0V, no load, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Clamping Current
Maximum Input Source
Resistance
Bias Voltage
Input Resistance
DC CHARACTERISTICS
DC Voltage Gain
Av
V
BIAS
Bias circuit
Bias circuit
Guaranteed by output-voltage swing
Guaranteed by output-voltage swing of
TV_R/C_OUT, TV_G_OUT, and TV_B_OUT;
first input signal set is VCR_R/C_IN,
VCR_G_IN, and VCR_B_IN; second signal set
is ENC_R/C_IN, ENC_G_IN, and ENC_B_IN
Sync-tip clamp (V
IN
= V
CLP
)
Bias circuit
Sync-tip clamp, measured at output, VVID =
3V, V
IN
= V
CLP
to (V
CLP
+1.15V), R
L
= 150Ω
to VVID/2, R
L
= 75Ω to GNDVID
Measured at output, VVID = 3.135V, V
IN
=
V
CLP
to (V
CLP
+1.2V), R
L
= 150Ω to VVID/2,
R
L
= 75Ω to GNDVID
Bias circuit, measured at output, VVID = 3V,
V
IN
= (V
BIAS
- 0.575V) to (V
BIAS
+ 0.575V),
R
L
= 150Ω to VVID/2, R
L
= 75Ω to GNDVID
Measured at output, VVID = 3.135V,
V
IN
= (V
BIAS
- 0.6V) to (V
BIAS
+ 0.6V),
R
L
= 150Ω to VVID/2, R
L
= 75Ω to GNDVID
Output Short-Circuit Current
Output Resistance
Output Leakage Current
Power-Supply Rejection Ratio
AC CHARACTERISTICS
Filter Passband Flatness
Filter Attenuation
Slew Rate
Settling Time
Differential Gain
Differential Phase
2T Pulse-to-Bar K Rating
DG
DP
V
OUT
= 2V
P-P
, f = 100kHz to 10MHz
V
OUT
= 2V
P-P
,
attenuation is referred
to 100kHz
f = 11MHz
f = 27MHz
f = 54MHz
-1
3
52
55
60
400
0.15
0.6
0.3
V/µs
ns
%
Degrees
MAX9598
SYMBOL
CONDITIONS
Sync-tip clamp, V
IN
= 0.3V
MIN
TYP
1
300
MAX
2
UNITS
µA
Ω
0.57
0.60
10
0.63
V
kΩ
1.95
2
2.05
V/V
DC Gain Mismatch Between R,
G, and B Outputs
-2
+2
%
Output Level
0.19
1.35
0.30
1.50
2.3
0.40
1.62
V
2.34
2.40
2.46
V
P-P
Output-Voltage Swing
2.3
2.34
2.40
100
2.46
mA
Ω
10
µA
dB
dB
dB
R
OUT
Output disabled (load detection not active)
3V
≤
VVID
≤
3.6V
50
0.5
V
OUT
= 2V
P-P
, no filter in video path
V
OUT
= 2V
P-P
, settle to 0.1% (Note 3)
5-step modulated staircase, f = 4.43MHz
5-step modulated staircase, f = 4.43MHz
2T = 200ns, bar time is 18µs; the beginning
2.5% and the ending 2.5% of the bar time are
ignored
K%
_______________________________________________________________________________________
3
Low-Power Audio/Video Switch for
Dual SCART Connectors
MAX9598
ELECTRICAL CHARACTERISTICS (continued)
(V12 = 12V, VVID = VAUD = 3.3V, V
GNDVID
= V
EP
= 0V, no load, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
2T Pulse Response
2T Bar Response
Nonlinearity
Group Delay Distortion
Glitch Impulse Caused by
Charge-Pump Switching
Peak Signal-to-RMS Noise
Power-Supply Rejection Ratio
Output Impedance
Video Crosstalk
Reverse Isolation
SYMBOL
2T = 200ns
2T = 200ns, bar time is 18µs; the beginning
2.5% and the ending 2.5% of the bar time
are ignored
5-step staircase
100kHz
≤
f
≤
5MHz, outputs are 2V
P-P
Measured at outputs
100kHz
≤
f
≤
5MHz
f = 100kHz, 100mV
P-P
f = 5MHz
f = 4.43MHz
VCR SCART inputs to encoder inputs, full-
power mode with VCR being looped
through to TV, f = 4.43MHz
Enable VCR_R/C_OUT pulldown through
I
2
C interface
V
IN
= -0.707V to +0.707V
V
IN
= -0.707V to +0.707V
f = 20Hz to 20kHz, 0.25V
RMS
input
0.25V
RMS
input, frequency where output is
-3dB referenced to 1kHz
No sustained oscillations, 75Ω series
resistor on output
V
IN
= -0.707V to +0.707V
V
IN
= 0V
f = 1kHz, THD < 1%
No input signal, V
IN
grounded
f = 1kHz, 0.25V
RMS
input, 20Hz to 20kHz
R
L
= 3.33kΩ, f = 1kHz, 0.25V
RMS
input
R
L
= 3.33kΩ, f = 1kHz, 0.5V
RMS
input
f = 1kHz
DC
f = 1kHz
f = 1kHz, 0.25V
RMS
input
f = 1kHz, 0.25V
RMS
input
75
-3
97
0.0014
0.001
0.4
100
90
110
92
0.5
+3
3.95
-1.5
0.006
230
300
10
500
CONDITIONS
MIN
TYP
0.2
0.2
0.1
11
100
70
42
2
-46
92
MAX
UNITS
K%
K%
%
ns
pVs
dB
dB
Ω
dB
dB
Pulldown Resistance
AUDIO CHARACTERISTICS
Voltage Gain
Gain Mismatch
Flatness
Frequency Bandwidth
Capacitive Drive
Input Resistance
Input Bias Current
Input Signal Amplitude
Output DC Level
Signal-to-Noise Ratio
Total Harmonic Distortion Plus
Noise
Output Impedance
Power-Supply Rejection Ratio
Mute Suppression
Audio Crosstalk
4.6
7.5
Ω
4
4.05
+1.5
V/V
%
dB
kHz
pF
MΩ
nA
V
RMS
mV
dB
%
Ω
dB
dB
dB
4
_______________________________________________________________________________________
Low-Power Audio/Video Switch for
Dual SCART Connectors
MAX9598
ELECTRICAL CHARACTERISTICS (continued)
(V12 = 12V, VVID = VAUD = 3.3V, V
GNDVID
= V
EP
= 0V, no load, T
A
= 0°C to +70°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
VIDEO-TO-AUDIO INTERACTION
Crosstalk
CHARGE PUMP
Switching Frequency
FAST SWITCHING
Input Low
Input High Level
Input Current
Output Low Voltage
Output High Voltage
Output Resistance
Rise Time
Fall Time
SLOW SWITCHING
Input Low Voltage
Input Medium Voltage
Input High Voltage
Input Current
Output Low Voltage
Output Medium Voltage
Output High Voltage
DIGITAL INTERFACE
Input High Voltage
Input Low Voltage
Input Hysteresis
Input Leakage Current
Input Capacitance
0.1VVID < SDA < 3.3V, 0.1VVID < SCL <
3.3V, I/O pins of fast-mode devices must
not obstruct the SDA and SCL lines if V+ is
switched off
V
OL
f
SCL
t
BUF
t
HD, STA
I
SINK
= 6mA
0
1.3
0.6
V
IH
V
IL
V
HYS
I
IH
, I
IL
-1
6
0.7 x VVID
0.3 x VVID
0.06 x VVID
+1
V
V
V
µA
pF
10kΩ to EP, 11.4V
≤
V12
≤
12.6V
10kΩ to EP, 11.4V
≤
V12
≤
12.6V
10kΩ to EP, 11.4V
≤
V12
≤
12.6V
5
10
4.5
9.5
70
100
1.5
6.5
2
7
V
V
V
µA
V
V
V
143Ω to GNDVID
143Ω to GNDVID
I
OL
= 0.5mA
I
OH
= 0.5mA
VVID - 0.1
7
12
10
1
10
0.1
0.4
V
V
µA
V
V
Ω
ns
ns
580
kHz
Video input: f = 15kHz, 1V
P-P
signal,
Audio input: f = 15kHz, 0.5V
RMS
signal
92
dB
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
Input Current
-10
+10
µA
Output Low Voltage SDA
Serial Clock Frequency
Bus Free Time Between a STOP
and a START Condition
Hold Time, (Repeated) START
Condition
0.4
400
V
kHz
µs
µs
_______________________________________________________________________________________
5
嵌入式系统
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
