Micrel MIC1700 Hdtv/sdtv 6th order video filter for component video plus composite video Datasheet

MIC1700
Micrel
MIC1700
HDTV/SDTV 6th Order Video Filter for Component
Video plus Composite Video
General Description
Features
The MIC1700 is a complete reconstruction filter solution for
high definition set-top boxes.
The device has two independent component inputs (YPRPB
or RGB) selectable via a 2-to-1 multiplexer, and a separate Svideo input (Y/C). Component channel filters have a selectable 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 150Ω loads. This supports 1V peak-to-peak into
a 75Ω load with a 75Ω series source terminator.
Filters have 6th order near Butterworth characteristics with
cutoffs of 8MHz (SD and CV) and 36MHz (HD). These
characteristics are chosen to provide good passband flatness 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.
•
•
•
•
•
•
•
•
•
•
•
S-video (Y/C) input, S-video and summed (CV) output
2 YPRPB or RGB inputs, YPRPB or RGB output
YPRPB/RGB 2-1 input multiplexer
DC coupled inputs – AC-coupled output drive
6db output gain for 75Ω source termination
Component filters selectable for SD or HD cutoffs
6th 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
0°C to +70°C
SOIC-28
MIC1700BWME
Typical Application
MIC1700x-x
HSEL
1
Y1A
2
Y1B
3
PR1
4
PR2
5
6
Composite
Inputs
PB1
7
PB2
8
YIN
CIN
9
10
11
MUX
12
HSEL
Y1A
Y1B
VCC
VCC
Y1OUT
VCC
28
27
26
4.7µF
220µF
0.1µF
75Ω
Y1OUT
75Ω
PR1
PROUT
25
PBOUT
PB1
GND
PB2
YOUT
YIN
75Ω
COUT
24
220µF
75Ω
22
MUX
PBOUT
75Ω
23
220µF
75Ω
YOUT
75Ω
21
220µF
75Ω
COUT
75Ω
CIN
GND
PROUT
75Ω
PR2
GND
220µF
CVOUT
GND
VCC
GND
20
220µF
18
75Ω
CVOUT
75Ω
19
VCC
17
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
October 2003
1
MIC1700
MIC1700
Micrel
Pin Configuration
HSEL 1
28 VCC
Y1A 2
27 VCC
Y1B 3
26 Y1OUT
PR1 4
25 PROUT
PR2 5
24 PBOUT
GND 6
23 GND
PB1 7
22 YOUT
PB2 8
21 COUT
YIN 9
20 CVOUT
CIN 10
19 GND
GND 11
18 VCC
MUX 12
17 GND
NC 13
16 NC
NC 14
15 NC
28-Pin Wide Body SOIC (WM)
Pin Description
Pin Number
Pin Name
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
PR (Input): component channel 1, selected when the MUX is high. 0V to 1V
range.
5
PR2
PR (Input): component channel 2, selected when the MUX is low. 0V to 1V
range.
6, 11, 17, 19, 23
GND
Ground.
7
PB1
PB (Input): component channel 1, selected when the MUX is high. 0V to 1V
range.
8
PB2
PB (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
18, 27, 28
VCC
20
CVOUT
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.
MIC1700
Pin Function
No connect. Do not connect these pins.
Positive side of the 5V power supply.
Legacy composite video output, typically 1V to 3V.
2
October 2003
MIC1700
Micrel
Truth Table
MUX Select Pin
H
L
H
HDTV Mode
Y1A, PB1, PR1 Inputs
HDTV Mode
Y1B, PB2, PR2 Inputs
L
SD Mode
Y1A, PB1, PR1 Inputs
SD Mode
Y1B, PB2, PR2 Inputs
HSEL
October 2003
3
MIC1700
MIC1700
Micrel
Absolute Maximum Ratings (Note 1)
Operating Ratings (Note 2)
Maximum Input Voltage ................................................ VCC
Supply Voltage ................................................................ 6V
Lead Temperature (soldering, 5 sec) ........................ 260°C
ESD Rating, ............................................................. Note 3
Analog Input Voltage Range .............................. 0V to 1.1V
Digital Input Voltage Range ................................... 0 to VCC
Supply Voltage (VCC) ...............................................5V±5%
Ambient Temperature Range ....................... –0°C to +70°C
Package Thermal Resistance
SOIC (θJA), Note 4, 6 .......................................... 35°C/W
Electrical Characteristics (Note 5)
VCC = 4.75V to 5.25V, TA = 25°C. Values in bold apply over entire operating temperature range. TA from 0°C to +70°C. Values apply to all channels unless noted.
Symbol
Parameter
Conditions
PD
Power Dissipation
VO
Typ
Max
Units
No load
725
900
mW
Linear Output Range
RL = 150Ω, AC-Coupled
2.0
2.2
V
ZIN
Input Impedance, Note 7
VIN = 0V to 1V
1
MΩ
IIN
Input Bias Current, Note 7
VIN = 0V to 1V
40
µA
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
Power Supply Rejection Ratio
at 400kHz
40
dB
36
MHz
30
MHz
dB
PSSR
Min
Filter Specifications, HD Operating Mode
f–3dB
–3dB Bandwidth
VAC = 0.5Vp-p, VDC = 0.5V
f–1dB
–1dB Bandwidth
VAC = 0.5Vpk-pk, VDC = 0.5V
A74MHz
74MHz Attenuation
VAC = 0.5Vpk-pk, VDC = 0.5V
25
30
Av
Low Frequency Gain
VAC = 0.5Vpk-pk, VDC = 0.5V at 400kHz
5.5
6
Av
Gain Matching
VAC = 0.5Vpk-pk, VDC = 0.5V
channel-to-channel
PK
Peaking, Note 7
TD
Baseband Delay
TGD
33
30
6.3
dB
1
%
1
dB
f = 100kHz
65
ns
Group Delay distortion
f = 3.6MHz
f = 6.0MHz
5
20
ns
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
°
7.9
MHz
Filter Specifications, NTSC/PAL Operating Mode
f–1dB
–1dB Bandwidth
VAC = 0.5Vpk-pk, VDC = 0.5V
f–3dB
–3dB Bandwidth
VAC = 0.5Vpk-pk, VDC = 0.5V
7.6
8.7
MHz
A27MHz
27MHz Attenuation
VAC = 0.5Vpk-pk, VDC = 0.5V
36
44
dB
Av
Low Frequency Gain
VAC = 0.5Vpk-pk, VDC = 0.5V at 400kHz
5.5
6
Av
Gain Matching
channel-to-channel
1
%
GD
Group Delay, Note 7
f = 3.6MHz
70
ns
SNR
Signal to Noise, Note 7
Note 8
68
dB
VIH
Input High
HSTL and MUX pin
VIL
Input Low
HSTL and MUX pin
6.3
dB
Digital I/O
MIC1700
4
2.0
V
0.5
V
October 2003
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. VIN = 1Vpk-pk. Wideband noise floor over 20MHz.
October 2003
5
MIC1700
MIC1700
Micrel
Typical Characteristics
10
0
3
2
1
0
-1
-2
1M
100M
HDTV Gain
20
7
6
10
0
5
4
-10
-20
3
2
-1
-2
1M
10M
1M
100M
2
4
100M
-70
-80
1M
6
8
10 12 14 16
FREQUENCY (MHz)
HDTV Group Delay
HDTV Gain
35
30
-30
-40
-50
-60
10M
FREQUENCY (Hz)
Input Signal =
50mVp-p
VDC = 0.5V
110
100
90
80
70
60
50
40
30
20
10
0
0
FREQUENCY (Hz)
1
0
MIC1700
-30
-40
-70
-80
100k
GAIN (dB)
GAIN (dB)
8
-10
-20
-50
-60
10M
FREQUENCY (Hz)
GROUP DELAY (ns)
5
4
Input Signal =
50mVp-p
VDC = 0.5V
NTSC Group Delay
NTSC Gain
20
GROUP DELAY (ns)
GAIN (dB)
7
6
NTSC Gain
GAIN (dB)
8
Input Signal =
50mVp-p
VDC = 0.5V
10M
FREQUENCY (Hz)
6
25
20
15
10
5
100M
0
0
10
20
30
40
50
60
FREQUENCY (MHz)
October 2003
MIC1700
Micrel
Functional Diagram
HSEL
(HDTV or
NTSC/PAL
Select)
MUX Select
Y1A
Y1B
2:1 MUX
Selectable Filter
Y1OUT
PR1
PR2
2:1 MUX
Selectable Filter
PROUT
PB1
PB2
2:1 MUX
Selectable Filter
PBOUT
Component
Video
YOUT
YIN
8MHz Filter
CVOUT
CIN
Composite
Video
8MHz Filter
COUT
MIC1700 Block Diagram
between 8MHz SD (Standard Definition) and 36MHz HD
(High Definition). The 6th 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 additionally specified for DG (differential gain, variation of subcarrier
amplitude with luma level) and DP (differential phase, variation 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 separate 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 150Ω 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 preventing excessive DC components from coupling to downstream equipment.
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 bandwidths 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 75Ω loads
via a 75Ω 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 specifications. Two groups of three pins each comprise the two
selectable component inputs, intended for YPRPB 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 characteristics are not altered by the action of the multiplexer.
Component Filters
The component filters are 6th order with near Butterworth
response characteristics. Cutoff frequencies are selectable
October 2003
7
MIC1700
MIC1700
Micrel
Applications Information
+5V
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).
R1
1.5k
Q4
Q2N3904
RGB Video Source
+5V
Comparison of Response
0
C2*
10µF
MIC1700
Q5
Q2N3904
+5V
C3*
10µF
-10
R3
20k
R4
20k
MIC1700
C1*
10µF
10
GROUP DELAY (ns)
+5V
Q6
Q2N3904
-20
-30
R5
20k
MIC1700 with
Passive Filter
-40
-50
Stopband
Improvement
-60
1
10
100
C4
10µF
300
Q7
Q2N3904
FREQUENCY (MHz)
*Polarity dependant on DC operating point of source
Figure 1. Comparison of Response
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 replaced during sync tip by the emitter current of the clamping
transistor. The VBE 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 4.7µs/63.5µs = 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 100µA, 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 1.5kΩ. 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.
22pF
75Ω
Encoder
Output
220nH
MIC1700
Input
62pF
Figure 2. Passive Filter Circuit for 75Ω source
47pF
37.5Ω
Encoder
Output
100nH
MIC1700
Input
130pF
Figure 3. Passive Filter Circuit for 37.5Ω source
MIC1700
8
October 2003
MIC1700
Micrel
+5V
+5V
R1
1.5k
Q4
Q2N3904
R2
20k
C4
10µF
Q7
Q2N3904
MIC1700
RGB Video Source
C1*
10µF
+5V
C2*
10µF
R4
1.8k
*Polarity dependant on DC operating point of source
Figure 5. Clamp and AC Biasing for S-Video Applications
October 2003
9
MIC1700
MIC1700
Micrel
Package Information
28-Pin Wide Body SOIC (WM)
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.
MIC1700
10
October 2003
Similar pages