19-3212; Rev 0; 1/08
KIT
ATION
EVALU
BLE
AVAILA
Three-Channel, High-Definition Video Filter
General Description
The MAX11500 integrated three-channel high-definition
(HD) video filter includes input video clamps and output
buffers. This device is ideal for anti-aliasing and DAC
smoothing video applications such as set-top boxes,
hard-disk recorders (HDRs), DVD players, and person-
al video recorders.
The 6th-order channel filters have a typical -3dB band-
width of 33MHz. Each channel has an output buffer with
a gain of +6dB and can drive a full 2V
P-P
video signal
into one standard 150Ω video load. These buffers can
drive either an AC- or DC-coupled load such that the
blanking level voltage after the backmatch resistor is
less than 1V.
The video inputs feature a transparent clamp for AC-
and DC-coupled input signals. If the input signal does
not go below ground, the input clamp is inactive, thus
enabling DAC outputs to be DC-coupled to the input.
The device operates from a single +5V supply, is offered
in the upper commercial 0°C to +85°C temperature
range, and is available in a small 8-pin SO package.
Features
♦
Three-Channel 6th-Order Filter for High-Definition
Video
♦
+6dB Output Buffers
♦
Transparent Input Clamps
♦
AC- or DC-Coupled Inputs
♦
AC- or DC-Coupled Outputs
♦
Output Buffers Drive One Standard 150Ω Video
Load
♦
12kV HBM ESD Protection on Outputs
♦
Single +5V Power Supply
♦
Small 8-Pin SO package
MAX11500
Applications
High-Definition Set-Top Box Receivers
HD Television Sets
HD Recorders
DVD Players
Personal Video Recorders
Video-On-Demand
PART
MAX11500USA+
Ordering Information
TEMP RANGE
0°C to +85°C
PIN-
PACKAGE
8 SO
PKG
CODE
S8-2
+Denotes
a lead-free package.
Typical Operating Circuit
V
CC
Pin Configuration
TOP VIEW
MAX11500
IN1
TRANSPARENT
CLAMP
33MHz
+6dB
OUT1
IN1
IN2
IN2
TRANSPARENT
CLAMP
33MHz
+6dB
OUT2
IN3
1
2
+
8
7
OUT1
OUT2
OUT3
GND
MAX11500
3
6
5
V
CC
4
IN3
TRANSPARENT
CLAMP
33MHz
+6dB
OUT3
SO
GND
________________________________________________________________
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.
Three-Channel, High-Definition Video Filter
MAX11500
ABSOLUTE MAXIMUM RATINGS
V
CC
to GND ..............................................................-0.3V to +6V
All other pins to GND......-0.3V to the lower of (V
CC
+ 0.3V) and +6V
Continuous Power Dissipation (T
A
= +70°C)
8-Pin SO (derate 5.9mW/°C above +70°C)...............470.6mW
Maximum Current into any Pin Except V
CC
and GND......±50mA
Operating Temperature Range
MAX11500USA ...................................................0°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Junction Temperature ......................................................+150°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
(V
CC
= +5V, R
LOAD
= 150Ω to GND, C
IN
= 0.1µF, T
A
= 0°C to +85°C, unless otherwise specified. All frequency response is relative
to 100kHz.)
PARAMETER
-1dB Bandwidth
-3dB Bandwidth
Stopband Attenuation
Low-Frequency Gain
Low-Frequency Gain
Matching
Input Voltage Range
Total Harmonic
Distortion
Channel-to-Channel
Crosstalk
Signal-to-Noise Ratio
Group Delay
Group-Delay Deviation
Supply Voltage Range
Supply Current
SYMBOL
f
1dB
f
3dB
f = 37.125MHz
A
SB
A
V
A
V(MATCH)
V
IN
THD
Referenced to GND if DC-coupled
V
OUT
= 1.4V
P-P
, f = 10MHz
V
OUT
= 1.4V
P-P
, f = 15MHz
V
OUT
= 1.4V
P-P
, f = 22MHz
X
TALK
SNR
t
g
∆t
g
V
CC
I
CC
No load
f = 1MHz
Peak signal (2V
P-P
) to RMS noise,
f = 100kHz to 30MHz
f = 100kHz
f = 100kHz to 26MHz
4.75
f = 44.25MHz
f = 74.25MHz, T
A
= +25°C
32
5.4
T
A
= +25°C
CONDITIONS
MIN
23
TYP
30
33
6.5
15.5
48
6.0
0.01
1.7
0.15
0.2
0.8
-72
68
25
8
5
24
5.25
38
dB
dB
ns
ns
V
mA
%
6.6
dB
dB
V
dB
MAX
UNITS
MHz
MHz
Note 1:
All devices are 100% production tested at T
A
= +25°C.
2
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Three-Channel, High-Definition Video Filter
Typical Operating Characteristics
(V
CC
= +5V, outputs AC-coupled with 220µF, R
LOAD
= 150Ω to GND, C
IN
= 0.1µF, T
A
= +25°C. All frequency response is relative to
100kHz.)
MAGNITUDE RESPONSE
(PASSBAND AND STOPBAND)
MAX11500 toc01
MAX11500
MAGNITUDE RESPONSE
(PASSBAND)
7.5
7.0
MAX11500 toc02
GROUP DELAY
MAX11500 toc03
20
8.0
60
50
40
DELAY (ns)
30
20
10
0
0
RESPONSE (dB)
RESPONSE (dB)
-20
6.5
6.0
5.5
5.0
4.5
-40
-60
-80
0.1
1
10
100
FREQUENCY (MHz)
4.0
0.1
1
10
100
FREQUENCY (MHz)
0.1
1
10
100
FREQUENCY (MHz)
2T RESPONSE
MAX11500 toc04
HD MULTIBURST RESPONSE
(1MHz–10MHz)
MAX11500 toc05
HD MULTIBURST RESPONSE
(20MHz–30MHz)
MAX11500 toc06
200mV/div
200mV/div
200mV/div
200mV/div
200mV/div
200mV/div
40ns/div
4µs/div
4µs/div
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3
Three-Channel, High-Definition Video Filter
MAX11500
Pin Description
PIN
1
2
3
4
5
6
7
8
NAME
IN1
IN2
IN3
V
CC
GND
OUT3
OUT2
OUT1
FUNCTION
Video Input Channel 1
Video Input Channel 2
Video Input Channel 3
Power Supply. Bypass to GND with 0.1µF
and 1µF capacitors.
Ground
Video Output Channel 3
Video Output Channel 2
Video Output Channel 1
Typical voltage waveforms are shown in Figures 1 and 2.
Transparent Clamps
All inputs feature a transparent clamp that allows either
AC- or DC-coupling of the inputs. The clamp remains
inactive while the input signal is above ground, offering
true DC input coupling. If the signal goes below
ground, as is the case if it is AC-coupled, the clamp
sets the sync tip close to the ground level.
Input Coupling
The choice to AC- or DC-couple the input depends on
the video source. Many DACs have a current output
and are terminated to ground with a resistor; such sig-
nals can be conveniently DC-coupled. In cases where
the DC level of the video signal is unknown or outside
of the specified input range of the MAX11500, such sig-
nals require AC-coupling. Examples of the latter are
SCART inputs and DACs terminated to V
CC
.
Detailed Description
The MAX11500 integrates three high-definition (HD)
video filters, each with a transparent input clamp, a 6th-
order lowpass filter with a -3dB bandwidth of 33MHz,
and an output stage with a gain of 2V/V. The output sig-
nal is offset by typically 550mV to optimize driver per-
formance.
V
OUT
= 2 x V
IN
+ 0.55V
DC-Coupled Inputs
If the input is DC-coupled, the voltage must remain
above zero but not exceed the maximum input voltage
of 1.7V (typical).
2.55V
OUTPUT SIGNAL
MAX11500
IN_
1.0V
OUT_
1.15V
INPUT SIGNAL
0.3V
0.55V
0.0V
Figure 1. Typical AC-Coupled Signal
4
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Three-Channel, High-Definition Video Filter
MAX11500
2.59V
OUTPUT SIGNAL
MAX11500
1.02V
IN_
OUT_
1.19V
INPUT SIGNAL
0.32V
0.59V
0.02V
0.00V
Figure 2. Typical DC-Coupled Signal
AC-Coupled Inputs
If the input is AC-coupled, the transparent clamp will be
active and sets the sync tip or the lowest voltage of the
signal close to ground. This clamping behavior is
appropriate for unipolar signals such as Y, R, G, or B
with or without sync pulse (Figure 3).
For bipolar signals such as Pb, Pr signals, the AC-coupled
inputs should be biased to a fixed DC voltage to ensure
that the transparent clamp never turns on. A suitable
network that biases the input to typically 0.59V is shown
in Figure 4. The device has an input leakage current
(I
L
) of typically 0.5µA and thus the bias voltage is
derived as follows:
V
B
=
R2
(V
CC
−
I
L
x R1)
R1
+
R2
ENCODER
0.1µF
DAC
IN_
MAX11500
Figure 3. AC-Coupling for Unipolar Signals (Y, R, G, B)
V
CC
ENCODER
0.1µF
DAC
R2
120kΩ
R1
820kΩ
IN_
HD Filters
The internal filters are optimized to deliver a flat pass-
band along with high stopband attenuation. The filter
characteristic has been chosen to provide an excellent
time-domain response with low overshoot. The typical
-3dB frequency of 33MHz guarantees low attenuation
in the passband, while at the same time allowing for a
typical attenuation of -48dB at 74.25MHz.
MAX11500
Figure 4. AC-Coupling for Bipolar Signals (Pb, Pr)
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