Fairchild Semiconductor FMS6414 Datasheet

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FMS6414

Dual Channel Video Drivers with Integrated Filters

Video Features

• Dual Integrated Video Low Pass reconstruction filters on
outputs

• Integrated output drivers provide low impedance outputs
and deliver 2Vp-p (6dB gain) composite video into 150 Ω .

• 7.1MHz 4

• 0.4% differential gain with 0.4° differential phase

• Integrated DC Restore / Clamp Circuitry

th

order video filters

Applications

• CCTV

• Cable and Satellite Set top boxes

• DVD players

• Televisions

• HDTV

• Personal Video Recorders (PVRs)

• Video On Demand (VOD)

Functional Block Diagram

YIN

1

REF, AND TIMI

General Description

The FMS6414 Dual Channel Video Filter – Driver Chip
offers comprehensive video filtering for set top box or DVD
applications. This part consists of two 4
Pass Filters for video filtering. This device integrates video
drivers so that it can directly drive to the outside world.

The video signals are filtered at 7.1MHz and buffered to
drive 2Vp-p into AC coupled 150 Ω loads with up to 35pF of
load capacitance at the output pin. The filters approximate a
4th-order Butterworth characteristic with an optimization
toward low overshoot and flat group delay. Likewise, they
are capable of driving a 75 Ω load at 1Vp-p. There is an
option for the video output to be DC coupled which limits
the drive to 1 output.

SYNC STRIP,

NG

YOUT

x2

8

th

order video Low

2

NC (Reserved)

3

GND_VIDEO

4

CIN

gM

gM

1V

FMS6414

1V

VCC_VIDEO

NC (Reserved)

x2

COUT

7

6

5

REV. 1.0.1 6/27/02

PRODUCT SPECIFICATION FMS6414

Pin Description

FMS6414

8-Pin SOIC (S08)

1

YIN

2

NC

3

GND_VIDEO

4

CIN

VCC_VIDEO

Video Section

Pin# Pin Type Description

1 YIN Input Luma (Luminance) / Composite Input
4 CIN Input Chroma (Chrominance) Input
5 COUT Output Filtered Chroma (Chrominance) Output
8 YOUT Output Filtered Luma (Luminance) Output

Power/Ground Pins

Pin# Pin Type Description

7 VCC_VIDEO Power +5 VDC for Video
3 GND_VIDEO Power Ground for Video
6 NC NC Reserved (Need to Float)
2 NC NC Reserved (Need to Float)

Y_OUT

NC

COUT

8

7

6

5

2

REV. 1.0.1 6/27/02

FMS6414 PRODUCT SPECIFICATION

Functional Description

Introduction

The FMS6414 is a monolithic continuous time video filter
designed for reconstructing the luminance, chrominance,
or composite video signals from D/A source. The chip is
intended for use in applications with AC coupled input and
AC coupled outputs. (See Figure 1) The reconstruction filters
approximate a 4th-order Butterworth characteristic with an
optimization toward low over-shoot and flat group delay.
The video outputs are each capable of driving 2VP-P into an
AC coupled 150 Ω video load, with up to 35pF of load
capacitance at the output pin. The channel is clamped during
sync to establish the appropriate output voltage swing range.
Thus the input coupling capacitors do not behave according
to the conventional RC time constant. Clamping for all
channels settles to less than 10mv within 5ms of a change in
video input source. In most applications the input coupling
capacitors are 0.1µF. The input typically sinks 1µA during
active video, which nominally tilts a horizontal line by about
2mV at the Video output. During sync, the clamp typically

Typical Applications Diagram

YIN

0.1µF

1

YIN YOUT

SYNC STRIP,

REF, AND TIMING

sources 20µA to restore the DC level. The net result is that
the average input current is zero. Any change in the input
coupling capacitor’s value will inversely alter the amount of
tilt per line. Such a change will also linearly affect the clamp
response time. This product is robust and stable under all
stated load and input conditions. Capacitive bypassing VCC
directly to ground ensures this performance.

Video I/O

The video inputs are driven by either a low impedance
source of 1VP-P or the output of a 75 Ω terminated line.
The input is required to be AC coupled via a 0.1µF coupling
capacitor which allows for a settling time of 5ms. The video
output is capable of driving an AC coupled 150 Ω load at
2VP-P, or 1VP-P into a 75 Ω load. Up to 35pF of load
capacitance (at the output pin) can be driven without stability
or slew issues. The output is AC coupled with a 220µF or
larger AC coupling capacitor.

220µF

x2

8

75Ω

Video Cable

75Ω

YOUT

CIN

0.1µF

2

NC (Reserved)

3

GND_VIDEO

4

CIN

gM

gM

1V

FMS6414

1V

VCC_VIDEO

NC (Reserved)

x2

Figure 1.

COUT

7

0.1µF

6

220µF

5

75Ω

+5.0V

1µF

Video Cable

75Ω

COUT

REV. 1.0.1 6/27/02

3