Analog Devices AN562 Application Notes

AN-562

a

APPLICATION NOTE

One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106 • 781/329-4700 • World Wide Web Site: http://www.analog.com

Filter Specification for the Internal Filters of the

ADV7190/ADV7191/ADV7192/ADV7194 Video Encoders

INTRODUCTION

This application note documents the filter specifications
and detailed plots of the internal filters of the ADV7190/
ADV7191, ADV7192 and ADV7194 video encoders.

All the above-mentioned devices provide two luma low­pass filters, two luma notch filters, an extended SSAF™
(Super Sub Alias Filter) luma low-pass filter, a luma CIF
and a luma QCIF filter, five chroma low-pass filters, a
Chroma CIF and a Chroma QCIF filter.

The SSAF filter, as can be seen in Figure 5, provides a
sharp stopband attenuation that enables studio quality
video playback on modern TVs, giving optimal horizon­tal line resolution.

Additionally, it is possible to change the response of the
SSAF filter in the passband in using the programmable
gain/attenuation feature or sharpness control as can be

seen in Figures 6, 7 and 8. Overall, there are six program­mable gain responses (Figure 7) and six programmable
attenuation responses (Figure 8) in the range of –4 dB to
+4 dB available. These responses can be programmed
over the I

The tables on the following pages show the filter specifi­cations for all the filters in 2× oversampling and 4×
oversampling mode.

Figures 1–17 highlight the frequency responses in the
passband and stopband.

Figures 18–31 highlight the different frequency responses
in 2× oversampling and 4× oversampling.

Tables I, II, III, and IV apply to the ADV7190/ADV7191,
ADV7192 and ADV7194 video encoders.

2C®

interface.

Table I. Luminance Internal Filter Specifications (2ⴛ Oversampling)

Passband 3 dB Stopband Stopband

1

Ripple

Filter Type Filter Selection (dB) (MHz) (MHz) (dB)

MR04 MR03 MR02
Low-Pass (NTSC) 0 0 0 0.09 4.158 6.05 –65.7
Low-Pass (PAL) 0 0 1 0.15 4.74 6.41 –81.1
Notch (NTSC) 0 1 0 0.09 2.25/5.0/6.54 8.03 –88
Notch (PAL) 0 1 1 0.095 3.07/5.8/6.24 8.02 –80.5
Extended (SSAF) 1 0 0 0.017 6.37 8.03 –87.4
CIF 1 0 1 0.012 3.0 5.09 –69.2
QCIF 1 1 0 0.118 1.5 3.74 –88.4

NOTES

1

Passband Ripple refers to the maximum fluctuations from the 0 dB response in the passband, measured in dB. The passband is defined to have 0 (Hz) to
fc (Hz) frequency limits for a low-pass filter, 0 (Hz) to f1 (Hz) and f2 (Hz) to infinity for a notch filter, where fc, f1, f2 are the –3 dB points.

2

3 dB bandwidth refers to the –3 dB cutoff frequency.

3

Stopband Cutoff refers to the frequency (MHz) at attenuation point (dB) referred to under Note 4.

4

Stopband Attenuation refers to the attenuation (dB) at the frequency (MHz) referred to under Note 3.

SSAF is a trademark of Analog Devices, Inc.
I2C is a registered trademark of Philips Corporation.

Bandwidth

2

Cutoff

3

Attenuation

REV. 0

4

AN-562

Table II. Chrominance Internal Filter Specifications (2ⴛ Oversampling)

Passband 3 dB Stopband Stopband
Ripple

1

Bandwidth

Filter Type Filter Selection (dB) (MHz) (MHz) (dB)

MR07 MR06 MR05

1.3 MHz Low-Pass 0 0 0 0.087 1.397 2.46 –84

0.65 MHz Low-Pass 0 0 1 Monotonic 0.653 2.41 –78.3

1.0 MHz Low-Pass 0 1 0 Monotonic 1.0 1.89 –66.6

2.0 MHz Low-Pass 0 1 1 0.0438 2.21 3.1 –65

3.0 MHz Low-Pass 1 0 0 Monotonic 3.18 5.33 –84.9
CIF 1 0 1 Monotonic 0.653 2.41 –78.3
QCIF 1 1 0 Monotonic 0.5 1.75 –33.17

Table III. Luminance Internal Filter Specifications (4ⴛ Oversampling)

Passband 3 dB Stopband Stopband
Ripple

1

Bandwidth

Filter Type Filter Selection (dB) (MHz) (MHz) (dB)

MR04 MR03 MR02
Low-Pass (NTSC) 0 0 0 0.16 4.24 6.05 –75.2
Low-Pass (PAL) 0 0 1 0.1 4.81 6.41 –64.6
Notch (NTSC) 0 1 0 0.09 2.27/4.9/6.6 8.03 –87.3
Notch (PAL) 0 1 1 0.1 3.1/5.6/6.4 8.02 –79.7
Extended (SSAF) 1 0 0 0.043 6.45 8.03 –86.6
CIF 1 0 1 0.127 3.02 5.09 –62.6
QCIF 1 1 0 Monotonic 1.5 3.74 –88.2

2

2

Cutoff

Cutoff

3

3

Attenuation

Attenuation

4

4

Table IV. Chrominance Internal Filter Specifications (4ⴛ Oversampling)

Passband 3 dB Stopband Stopband
Ripple

1

Bandwidth

2

Cutoff

3

Attenuation

Filter Type Filter Selection (dB) (MHz) (MHz) (dB)

MR07 MR06 MR05

1.3 MHz Low-Pass 0 0 0 0.09 1.395 2.46 –83.9

0.65 MHz Low-Pass 0 0 1 Monotonic 0.65 2.41 –71.1

1.0 MHz Low-Pass 0 1 0 Monotonic 1.0 1.89 –64.43

2.0 MHz Low-Pass 0 1 1 0.048 2.2 3.1 –65.9

3.0 MHz Low-Pass 1 0 0 Monotonic 3.2 5.3 –84.5
CIF 1 0 1 Monotonic 0.65 2.41 –71.1
QCIF 1 1 0 Monotonic 0.5 1.75 –33.1

NOTES

1

Passband Ripple refers to the maximum fluctuations from the 0 dB response in the passband, measured in dB. The passband is defined to have 0 (Hz) to
fc (Hz) frequency limits for a low-pass filter, 0 (Hz) to f1 (Hz) and f2 (Hz) to infinity for a notch filter, where fc, f1, f2 are the –3 dB points.

2

3 dB bandwidth refers to the –3 dB cutoff frequency.

3

Stopband Cutoff refers to the frequency (MHz) at attenuation point (dB) referred to under Note 4.

4

Stopband Attenuation refers to the attenuation (dB) at the frequency (MHz) referred to under Note 3.

4

–2–

REV. 0

MAGNITUDE – dB

FREQUENCY – MHz

–70

0

71

MAGNITUDE – dB

23456

–10

–30

–40

–50

–60

–20

0

0

8

FREQUENCY – MHz

–70

0

71

MAGNITUDE – dB

23456

–10

–30

–40

–50

–60

–20

0

0

8

AN-562

0

0

–10

–20

–30

–40

–50

–60

–70

0

23456

FREQUENCY – MHz

71

Figure 1. Luma NTSC Low-Pass Filter
(4

MAGNITUDE – dB

–10

–20

–30

–40

–50

–60

–70

×

0

0

0

Oversampling)

23456

FREQUENCY – MHz

71

Figure 2. Luma PAL Low-Pass Filter (4× Oversampling)

Figure 4. Luma PAL Notch Filter (4x Oversampling)

Figure 5. Extended (SSAF) Luma Filter
(4x Oversampling)

0

0

–10

–20

–30

–40

MAGNITUDE – dB

–50

–60

–70

0

23456

FREQUENCY – MHz

8

71

Figure 3. Luma NTSC Notch Filter (4x Oversampling)

Figure 6. Extended (SSAF) Luma Filter

MAGNITUDE – dB

–10

–12

0

4

2

0

–2

–4

–6

–8

0

2345 6

FREQUENCY – MHz

71

(4x Oversampling) with Programmable
Attenuation/Gain in the Passband

REV. 0

–3–