鈩?/div>
GF9102A
G
Decimating/Interpolating Digital Filter
DATA SHEET
FEATURES
鈥?improved performance over TMC2242 in applications
not requiring 1:1 low pass filtering
鈥?low power (60mA typical at 茠 = 20MHz)
鈥?40 MHz maximum clock rate
鈥?single device exceeds CCIR 601 lowpass filter
requirements
鈥?true unity gain (0.0 dB) at DC
鈥?reduced output ringing with constant input in
interpolation mode
鈥?built-in TRS code protection
鈥?12 bit inputs and 16 bit outputs in 2's complement
signed or unsigned formats
鈥?user-selectable 8 to 16 bit output rounding
鈥?can also be operated as a 9 or 21 tap chroma
bandpass filter under user control
鈥?single +5 V power supply
鈥?three state outputs
APPLICATIONS
鈥?CCIR 601-compliant oversampling video A/D and
D/A conversion
鈥?2:1 interpolation and decimation
鈥?4:2:2 to 4:4:4 format conversion
鈥?Chroma bandpass filtering
ORDERING INFORMATION
Part Number
GF9102ACPM
GF9102ACTM
Package Type
44 Pin PLCC
44 Pin PLCC Tape
CLK
DEC
DEVICE DESCRIPTION
The GF9102A is a linear phase FIR digital filter that is usable
in a variety of video signal processing applications. The device
contains three separate fixed coefficient filters and can be
operated in three basic modes: 53 tap low pass filter, 9 tap
chroma bandpass filter or 21 tap chroma bandpass filter.
In the 53 tap low pass filter mode, the GF9102A can replace the
TMC2242 in all applications, except those requiring 1:1 low
pass filtering, for improved performance and full CCIR 601
compatibility. Specific improvements include true unity gain at
DC, 12.4 dB attenuation at 茠s/4 with a single device, reduced
output ringing with constant input in interpolate mode, support
for signed and unsigned data formats, rounding to 10 and 8 bit
CCIR 601 data formats, masking of serial digital TRS codes in
the data stream, and elimination of the non-saturated-type
overflow condition. The device can be operated in both
TMC2242 compatible modes and in GF9102A enhanced
modes.
When used as a decimating post-filter with a double speed
oversampling analog-digital converter, the device greatly
reduces the cost and complexity of the associated analog
anti-aliasing pre-filter. In a similar fashion, when used as an
interpolating pre-filter with a double speed oversampling digital-
analog converter, the GF9102A simplifies the analog
reconstruction post-filter. The GF9102A also exceeds the
requirements for conversion between 4:2:2 and 4:4:4 signal
formats.
For chroma filtering applications, the GF9102A can be operated
as a 9 or 21 tap bandpass filter by selecting the appropriate
operating mode.
The GF9102A is packaged in a 44 pin PLCC and is pin
compatible with the TMC2242. The device operates with a
single +5 V supply.
Temperature Range
0擄 to 70擄 C
0擄 to 70擄 C
INT
SYNC
RND2..0
TCO
TIMING CONTROLS
OUTPUT FORMAT
SO3..0
DATA IN
SI11..0
INPUT
PROCESSING
UNIT
BPF1
BPF2
53 TAP LPF
M
U
X
OUTPUT
PROCESSING
UNIT
DATA OUT
SO15..0
Revision Date: February 1996
FUNCTIONAL BLOCK DIAGRAM
OE
Document No. 521 - 26 - 02
GENNUM CORPORATION P.O. Box 489, Stn A, Burlington, Ontario, Canada L7R 3Y3 tel. (905) 632-2996 fax: (905) 632-5946
Gennum Japan Corporation: A-302 Miyamae Village, 2-10-42 Miyamae, Suginami-ku, Tokyo 168, Japan
tel. (03) 3334-7700
fax (03) 3247-8839
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