Philips Semiconductors
Terrestrial digital sound decoder for
conventional intercarrier PLL-IF systems
Preliminary specification
SAA7284
FEATURES
• Single-chip solution including FM and vision filters,
analog demodulator and audio switching
• Dual standard with automatic selection between PAL
system I and BGH
• Suitable for conventional intercarrier PLL-IF
(single SAW) TV/VCR systems
• Single low-radiation crystal oscillator for improved EMC
• Stereo bitstream audio DACs
• Programmable attenuator for matching levels of NICAM
and FM audio sources at the output of the device
• Full EBU specification NICAM 728 demodulation and
decoding
• Digital Audio Interface conforming with EBU/IEC 958
• Automatic mute function which switches from NICAM to
FM sound when NICAM fails
• Compatible with either single-ended or differential
DQPSK input signals
• Microcomputer controlled via I2C-bus (up to 400 kHz
specification).
APPLICATIONS
• Television receivers
• Video cassette recorders.
The SAA7284 takes, as input, a second IF (intercarrier)
Terrestrial TV PAL signal, and performs all the Differential
Quadrature Phase Shift Keying (DQPSK) demodulation,
digital decoding and digital-to-analog conversion
necessary to produce a complete NICAM receiver on a
single integrated circuit.
The demodulator function includes integrated baseband
filters for pulse shaping and unwanted signal rejection,
automatic gain control, a low jitter integrated VCO, digital
monostables for precise data sampling points and a
multi-standard controller to enable automatic locking to
either a PAL system I or PAL system BGH input signal.
The decoder function performs the descrambling,
de-interleaving and reformatting operations required to
recover the original data words.
The data words are processed through a stereo digital
filter, digital de-emphasis network, second order noise
shaper and 256 times oversampling Bitstream audio DAC.
GENERAL DESCRIPTION
Philips Semiconductors have pushed the boundaries of
Stereo Sound further with this addition to the successful
Terrestrial Digital Sound Decoder family. The SAA7284
device is an application specific version of the existing
SAA7283, with guaranteed improved specification on
selected parameters, enabling comparable RF
performance in conventional intercarrier PLL-IF systems,
to that of the SAA7283 in QSS systems.
ORDERING INFORMATION
TYPE
NUMBER
SAA7284ZP
SAA7284GP
NAME
SDIP52
QFP64
PACKAGE
DESCRIPTION
plastic shrink dual in-line package; 52 leads (600 mil)
plastic quad flat package; 64 leads (lead length 1.95 mm);
body 14 × 20 × 2.8 mm
VERSION
SOT247-1
SOT319-2
1996 Oct 24
2