DRP3510 Datasheet, PDF (6/30 Pages) List of Unclassifed Manufacturers – Digital Receiver Front-end

DRX 3960A
ADVANCE INFORMATION
1.3. Analog TV Application
The Digital Receiver Front-end DRX 3960A is able to
replace a conventional IF IC including several SAWs.
Nevertheless, quasi split sound processing is per-
formed with standard specific internal filtering and
group delay equalizing.
The input signal of the DRX 3960A is the TV IF with its
carrier at:
– 38.9 MHz (B/G, D/K, I, L, and M/N in multistandard
applications)
– 32.9 MHz (L’)
– 45.75 MHz (M/N in single standard applications)
– other frequencies are also programmable
– 36.125 MHz (DVB-C or DVB-T in further versions)
These signals are available from conventional tuners.
For pre-filtering, one 8-MHz channel SAW filter must
be used, e.g. the Epcos X6966M. Nevertheless, the
entire multistandard processing is performed. The pre-
filter limits the signal bandwidth to 8 MHz and sup-
presses major parts of the adjacent channels.
After the desired standard information is transferred
into the DRX 3960A, the following standard specific
procedures are performed:
– Adjacent channel suppression
– Carrier locking including AFC information genera-
tion
– Nyquist slope adjustment
– Video/sound splitting
– Video AGC, including delayed tuner AGC
– Group delay post distortion
– Video and sound frequency shaping
– Video demodulation
– Second SIF generation and AGC
Similar to conventional analog front-ends, the tuner
gain is controlled by the DRX 3960A. New AGC algo-
rithms have been implemented for superior level track-
ing for both positive and negative video modulation.
The demodulated CVBS signal and the second sound
IF (SIF) are available as analog output signals.
If an FM radio channel is transferred to the IF inputs,
down-mixed by means of a standard TV tuner, it can
be preselected and further down-mixed by the
DRX 3960A. Thus, a succeeding sound demodulator,
e.g. the MSP, will be able to demodulate that channel.
The DRX 3960A operates with its own quartz or with
appropriate external clocks, e.g.:
– 13.5, 20.25, 27 MHz from an employed video IC
– 1, 4 MHz from the tuner
CVBS
VPC/VCT
Tuner
SAW
Delayed Tuner AGC
DRX 3960A
2^nd SIF
I²C
Fig. 1–2: Multistandard video and sound IF processing with DRX 3960A
MSP
6
Micronas