October 2003
1
MIC1700
MIC1700
Micrel
MIC1700
HDTV/SDTV 6
th
Order Video Filter for Component
Video plus Composite Video
General Description
The MIC1700 is a complete reconstruction filter solution for
high definition set-top boxes.
The device has two independent component inputs (YP
R
P
B
or RGB) selectable via a 2-to-1 multiplexer, and a separate S-
video input (Y/C). Component channel filters have a select-
able cutoff frequency (8MHz or 36MHz) to support both
standard (SD) and high definition (HD) applications. S-video
filters have fixed cutoff (8MHz) to support legacy composite
applications. In addition, S-video channels are summed to
provide a filtered CV output for an RF modulator or VCR. All
inputs are DC-coupled with a 0V to 1V peak-to-peak range.
All outputs are designed to drive 2V peak-to-peak into
AC-coupled 150 loads. This supports 1V peak-to-peak into
a 75 load with a 75 series source terminator.
Filters have 6
th
order near Butterworth characteristics with
cutoffs of 8MHz (SD and CV) and 36MHz (HD). These
characteristics are chosen to provide good passband flat-
ness with sufficient stop band attenuation and minimal group
delay distortion.
The device operates from a 5VDC supply.
Data sheets and support documentation are available at
Micrel's web site, www.micrel.com.
Typical Application
17
12
18
11
1
28
27
26
25
24
23
22
21
20
19
2
3
4
5
6
7
8
9
10
4.7
F
0.1
F
75
75
220
F
Y1OUT
PROUT
PBOUT
YOUT
COUT
CVOUT
V
CC
V
CC
MIC1700x-x
MUX
GND
HSEL
Y1A
Y1B
PR1
PR2
GND
PB1
PB2
YIN
CIN
GND
VCC
VCC
VCC
Y1OUT
PROUT
PBOUT
GND
YOUT
COUT
CVOUT
GND
75
75
75
75
75
MUX
HSEL
Y1A
Y1B
YIN
Composite
Inputs
CIN
PR1
PR2
PB1
PB2
220
F
220
F
220
F
220
F
220
F
75
75
75
75
75
Features
S-video (Y/C) input, S-video and summed (CV) output
2 YP
R
P
B
or RGB inputs, YP
R
P
B
or RGB output
YP
R
P
B
/RGB 2-1 input multiplexer
DC coupled inputs AC-coupled output drive
6db output gain for 75 source termination
Component filters selectable for SD or HD cutoffs
6
th
order Butterworth characteristic
Flat passband (HD 0.5dB @ 30MHz typ)
Low group delay distortion (HD: 12ns @ 30MHz typ)
Single 5V supply
28-pin wide body SOIC package (with exposed pad for
improved thermal performance)
Applications
HDTV
HDTV set-top boxes
Video games
HDTV systems
DVD players
Digital satellite set-top boxes
HDTV monitors
Ordering Information
Part Number
Junction Temp. Range
Package
MIC1700BWME
0C to +70C
SOIC-28
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
MIC1700
Micrel
MIC1700
2
October 2003
Pin Configuration
MUX
GND
17
12
GND
VCC
18
11
NC
NC
15
14
NC
NC
16
13
1
HSEL
Y1A
Y1B
PR1
PR2
GND
PB1
PB2
YIN
CIN
28
VCC
VCC
Y1OUT
PROUT
PBOUT
GND
YOUT
COUT
CVOUT
GND
27
26
25
24
23
22
21
20
19
2
3
4
5
6
7
8
9
10
28-Pin Wide Body SOIC (WM)
Pin Description
Pin Number
Pin Name
Pin Function
1
HSEL
Digital (Input): selects for the HD or SD filtering. A high selects HD filters.
2
Y1A
Y (Input): component channel 1, selected when the MUX is high. 0V to 1V
range.
3
Y1B
Y (Input): component channel 2, selected when the MUX is low. 0V to 1V
range.
4
PR1
P
R
(Input): component channel 1, selected when the MUX is high. 0V to 1V
range.
5
PR2
P
R
(Input): component channel 2, selected when the MUX is low. 0V to 1V
range.
6, 11, 17, 19, 23
GND
Ground.
7
PB1
P
B
(Input): component channel 1, selected when the MUX is high. 0V to 1V
range.
8
PB2
P
B
(Input): component channel 2, selected when the MUX is low. 0V to 1V
range.
9
YIN
Legacy (S-video): luminance input, 0V to 1V.
10
CIN
Legacy (S-video): chroma input, 0V to 1V.
12
MUX
Digital MUX control to select input 1 or 2 of the component channel. A high
selects input 1.
13, 14, 15, 16
NC
No connect. Do not connect these pins.
18, 27, 28
VCC
Positive side of the 5V power supply.
20
CVOUT
Legacy composite video output, typically 1V to 3V.
21
COUT
Legacy chroma output, typically 1V to 3V.
22
YOUT
Legacy luminance video output, typically 1V to 3V.
24
PBOUT
PB color component output, either SD or HD, typically 1V to 3V.
25
PROUT
PR color component output, either SD or HD, typically 1V to 3V.
26
Y1OUT
Luminance component output, either SD or HD, typically 1V to 3V.
October 2003
3
MIC1700
MIC1700
Micrel
Truth Table
MUX Select Pin
H
L
H
HDTV Mode
HDTV Mode
HSEL
Y1A, PB1, PR1 Inputs
Y1B, PB2, PR2 Inputs
L
SD Mode
SD Mode
Y1A, PB1, PR1 Inputs
Y1B, PB2, PR2 Inputs
MIC1700
Micrel
MIC1700
4
October 2003
Absolute Maximum Ratings
(Note 1)
Maximum Input Voltage ................................................ V
CC
Supply Voltage ................................................................ 6V
Lead Temperature (soldering, 5 sec) ........................ 260C
ESD Rating, ............................................................. Note 3
Operating Ratings
(Note 2)
Analog Input Voltage Range .............................. 0V to 1.1V
Digital Input Voltage Range ................................... 0 to V
CC
Supply Voltage (V
CC
) ............................................... 5V5%
Ambient Temperature Range ....................... 0C to +70C
Package Thermal Resistance
SOIC (
JA
), Note 4, 6 .......................................... 35C/W
Electrical Characteristics
(Note 5)
V
CC
= 4.75V to 5.25V, T
A
= 25C. Values in bold apply over entire operating temperature range. T
A
from 0C to +70C. Values apply to all channels unless noted.
Symbol
Parameter
Conditions
Min
Typ
Max
Units
P
D
Power Dissipation
No load
725
900
mW
V
O
Linear Output Range
R
L
= 150, AC-Coupled
2.0
2.2
V
Z
IN
Input Impedance, Note 7
V
IN
= 0V to 1V
1
M
I
IN
Input Bias Current, Note 7
V
IN
= 0V to 1V
40
A
Crosstalk, Note 7
channel-to-channel, f = 3MHz, NTSC Mode
70
dB
Crosstalk, Note 7
channel-to-channel, f = 20MHz, HDTV Mode
64
dB
Crosstalk, Note 7
between MUX inputs, f = 3MHz
60
dB
PSSR
Power Supply Rejection Ratio
at 400kHz
40
dB
Filter Specifications, HD Operating Mode
f
3dB
3dB Bandwidth
V
AC
= 0.5V
p-p
, V
DC
= 0.5V
33
36
MHz
30
f
1dB
1dB Bandwidth
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
30
MHz
A
74MHz
74MHz Attenuation
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
25
30
dB
Av
Low Frequency Gain
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V at 400kHz
5.5
6
6.3
dB
Av
Gain Matching
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
1
%
channel-to-channel
P
K
Peaking, Note 7
1
dB
T
D
Baseband Delay
f = 100kHz
65
ns
T
GD
Group Delay distortion
f = 3.6MHz
5
ns
f = 6.0MHz
20
ns
SNR
Signal to Noise, Note 7
Note 2
77
dB
DG
Differential Gain, Note 7
40IRE modulated ramp
2
%
DP
Differential Phase, Note 7
@ both 3.58MHz and 4.43MHz
2
Filter Specifications, NTSC/PAL Operating Mode
f
1dB
1dB Bandwidth
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
7.9
MHz
f
3dB
3dB Bandwidth
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
7.6
8.7
MHz
A
27MHz
27MHz Attenuation
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V
36
44
dB
Av
Low Frequency Gain
V
AC
= 0.5V
pk-pk
, V
DC
= 0.5V at 400kHz
5.5
6
6.3
dB
Av
Gain Matching
channel-to-channel
1
%
G
D
Group Delay, Note 7
f = 3.6MHz
70
ns
SNR
Signal to Noise, Note 7
Note 8
68
dB
Digital I/O
V
IH
Input High
HSTL and MUX pin
2.0
V
V
IL
Input Low
HSTL and MUX pin
0.5
V
October 2003
5
MIC1700
MIC1700
Micrel
Note 1.
Exceeding the absolute maximum rating may damage the device.
Note 2.
The device is not guaranteed to function outside its operating rating.
Note 3.
Devices are ESD sensitive. Handling precautions recommended.
Note 4.
With SOIC attached by leads only.
Note 5.
Specification for packaged product only.
Note 6.
When thermally enhanced SOIC heatsink pad is soldered to a copper pad on a single layer PCB.
Note 7.
Guaranteed by design and characterization.
Note 8.
Low pass filter enabled. V
IN
= 1V
pk-pk
. Wideband noise floor over 20MHz.
MIC1700
Micrel
MIC1700
6
October 2003
Typical Characteristics
-2
-1
0
1
2
3
4
5
6
7
8
GAIN (dB)
FREQUENCY (Hz)
NTSC Gain
1M
10M
100M
Input Signal =
50mV
p-p
V
DC
= 0.5V
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
GAIN (dB)
FREQUENCY (Hz)
NTSC Gain
100k
1M
10M
100M
Input Signal =
50mV
p-p
V
DC
= 0.5V
0
10
20
30
40
50
60
70
80
90
100
110
0
2
4
6
8
10 12 14 16
GROUP DELAY (ns)
FREQUENCY (MHz)
NTSC Group Delay
-2
-1
0
1
2
3
4
5
6
7
8
GAIN (dB)
FREQUENCY (Hz)
HDTV Gain
1M
10M
100M
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
GAIN (dB)
FREQUENCY (Hz)
HDTV Gain
1M
10M
100M
Input Signal =
50mV
p-p
V
DC
= 0.5V
0
5
10
15
20
25
30
35
0
10
20
30
40
50
60
GROUP DELAY (ns)
FREQUENCY (MHz)
HDTV Group Delay
October 2003
7
MIC1700
MIC1700
Micrel
Functional Description
The MIC1700 is a multi-channel active filtering device with
channels for both component and composite video signals.
Component channel filters have selectable SD or HD band-
widths while composite filters have fixed bandwidth. One of
two component inputs may be selected via a 2-to-1 mux.
Output drivers are sufficient to drive 1V signals into 75 loads
via a 75 source terminator.
Input
Inputs are all high impedance with low input bias current.
Signal excursions at the inputs are limited to a specified range
of 0V to 1V to meet distortion and other performance speci-
fications. Two groups of three pins each comprise the two
selectable component inputs, intended for YP
R
P
B
or RGB
applications. One group of two pins comprises the composite
S-video input, intended for legacy applications.
Component Multiplexer
Either of two component inputs may be selected using the
component input multiplexer. The output of this high isolation
multiplexer feeds the internal component filters. Input charac-
teristics are not altered by the action of the multiplexer.
Component Filters
The component filters are 6
th
order with near Butterworth
response characteristics. Cutoff frequencies are selectable
Functional Diagram
MUX Select
Y1OUT
PROUT
Component
Video
Composite
Video
PBOUT
YOUT
CVOUT
COUT
HSEL
(
HDTV or
NTSC/PAL
Select
)
Selectable Filter
Selectable Filter
Selectable Filter
2:1 MUX
2:1 MUX
2:1 MUX
8MHz Filter
CIN
YIN
PB2
PR2
PR1
Y1B
Y1A
PB1
8MHz Filter
between 8MHz SD (Standard Definition) and 36MHz HD
(High Definition). The 6
th
order Butterworth characteristic
provides a maximally flat passband with 39dB of attenuation
an octave above cutoff, and low group delay distortion
minimizes overshoots in the time domain.
Composite Filters
The composite filters have the same characteristics as the
SD mode of the component filters. These filters are addition-
ally specified for DG (differential gain, variation of subcarrier
amplitude with luma level) and DP (differential phase, varia-
tion of subcarrier phase with luma level). These distortions
(which are intermodulation distortions) cannot occur with true
S-video inputs applied, since luma and chroma are in sepa-
rate channels. However, the composite filters can also be
used with full legacy composite signals. In these cases, the
DG and DP specifications are applicable.
Output Drivers
The output drivers are configured to provide low distortion 2V
peak-to-peak swing into a 150 load from a single +5V
supply. To achieve this, the operating range is approximately
from 1V to 3V for normal inputs. AC-coupling at the outputs
helps keep power dissipation within specification while pre-
venting excessive DC components from coupling to down-
stream equipment.
MIC1700 Block Diagram
MIC1700
Micrel
MIC1700
8
October 2003
Applications Information
Achieving Additional Stop Band Attenuation
For customers requiring greater stop band attenuation, a
simple passive filter can be added to the input of MIC1700.
The following circuit increases stop band attenuation above
60MHz by at least 15dB. Attenuation at the critical clocking
frequency of 74MHz is increased by at least 20dB even
allowing for typical value variations (we recommend 5%
inductor, 2% capacitors).
-60
-50
-40
-30
-20
-10
0
10
1
10
100
300
GROUP DELAY (ns)
FREQUENCY (MHz)
Comparison of Response
MIC1700
MIC1700 with
Passive Filter
Stopband
Improvement
Figure 1. Comparison of Response
62pF
22pF
220nH
75
Encoder
Output
MIC1700
Input
Figure 2. Passive Filter Circuit for 75
source
130pF
47pF
100nH
37.5
Encoder
Output
MIC1700
Input
Figure 3. Passive Filter Circuit for 37.5
source
+5V
+5V
+5V
Q4
Q2N3904
Q5
Q2N3904
Q6
Q2N3904
R4
20k
Q7
Q2N3904
C4
10
F
C3*
10
F
C2*
10
F
C1*
10
F
+5V
R3
20k
R5
20k
RGB V
ideo Source
MIC1700
R1
1.5k
*Polarity dependant on DC operating point of source
Figure 4. Triple Clamp for RGB Applications
Clamps for AC-Coupled Inputs
For RGB or Composite inputs that do not meet the DC input
requirements MIC1700 can be driven via sync tip clamps
(RGB sources work best with sync on all channels). These
clamps work with signals that are unipolar, in which the sync
tip is the most negative excursion of the signal. Current is bled
from the input capacitor during active video causing a slow
droop in average level. This rate of droop is a critical video
parameter and should be well under 1% for all operating
conditions. The droop is controlled by the load resistance
(plus additional load currents) and the coupling cap. Charge
removed from the coupling cap during active video is re-
placed during sync tip by the emitter current of the clamping
transistor. The V
BE
drop during sync will be a function of the
replacement current which is a function of sync tip duty cycle.
Sync tip duty cycle for SD is 4.7s/63.5s = 0.074 or 7.4%.
For HD trilevel sync the duty cycle is about half of this or
0.037. Assuming a droop current of about 100A, this gives
a maximum replacement current (for HD signals) of 2.7mA.
To keep this sync tip at or above GND, the biasing transistor
should be operated at the same current, giving a biasing
resistor of 1.5k. This will bias HD sources with the sync tip
at GND, with SD sources slightly above GND. The luma
channel of S-video sources can be clamped the same as
component RGB channels, but the chroma channel should
simply be AC-coupled with a bias of 0.5V. Realization of
these schemes is shown in Figure 4 and 5.
October 2003
9
MIC1700
MIC1700
Micrel
+5V
+5V
Q4
Q2N3904
R1
1.5k
Q7
Q2N3904
C4
10
F
C2*
10
F
C1*
10
F
+5V
R2
20k
R4
1.8k
RGB V
ideo Source
MIC1700
*Polarity dependant on DC operating point of source
Figure 5. Clamp and AC Biasing for S-Video Applications
MIC1700
Micrel
MIC1700
10
October 2003
MICREL, INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131
USA
TEL
+ 1 (408) 944-0800
FAX
+ 1 (408) 944-0970
WEB
http://www.micrel.com
The information furnished by Micrel in this datasheet is believed to be accurate and reliable. However, no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specifications at any time without notification to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A Purchaser's
use or sale of Micrel Products for use in life support appliances, devices or systems is at Purchaser's own risk and Purchaser agrees to fully indemnify
Micrel for any damages resulting from such use or sale.
2003 Micrel, Incorporated.
Package Information
28-Pin Wide Body SOIC (WM)
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