ZL10210
DVB-C Cable Channel Demodulator
Data Sheet
Features
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DVB-C EN300429 and ITU-T J.83 annex A/C
compliant QAM demodulator
Conventional IF and low IF input supported
QAM constellations 16, 32, 64, 128 and 256
Symbol rates up to 9 MBaud
Blind acquisition of all symbol rates
Blind acquisition of QAM constellations
Single IF filter bandwidth for all symbol rates
Signal level, BER and SNR indicators
Programmable IF/RF AGC take-over point
Power down mode under software control
Parallel and serial MPEG outputs
External 4 or 27 MHz clock or single low-cost
10 MHz crystal
Small package size LQFP64 7x7 mm
Power consumption <300 mW at 6.9 MBaud
5 V tolerant 2-wire bus control interface
5 V tolerant GPIO port and AGC outputs
RF level detect facility via a separate ADC
Very low driver software overhead due to on-chip
state-machine control.
General purpose programmable timer
-40
o
C to +85
o
C
Ordering Information
ZL10210/GC/GP1N
64 Pin LQFP
November 2005
Description
The ZL10210 is a DVB-C and ITU-T annex A/C QAM
demodulator. This low power cable demodulator
includes standard Zarlink features of auto signal acqui-
sition, fast blind-scan capability, software/hardware
power down, RF level, BER and SNR detection. The
ZL10210 represents the latest in QAM demodulation
for DVB cable. Together with a cable tuner, a full digital
cable receiver front-end can be realized. Either
conventional intermediate frequencies such as 36 or
44 MHz or low intermediate frequencies can be used -
see application below. The ZL10210 requires only a
single channel filter bandwidth of 8 MHz nominal for full
DVB and ITU-T annex A/C performance. The low
power consumption, small package form factor and
integrated software/hardware power-down modes help
reduce the system BoM (bill of materials) in cost
sensitive applications. The device is packaged in a
7 x 7 mm 64-pin LQFP.
Applications
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Set-top boxes
Digital cable ready TV applications
Cable modems
SMATV/MATV receivers
Functional Description
The ZL10210 accepts an analog signal from the tuner,
either at low Intermediate Frequency (IF) or conven-
tional IF up to 50 MHz, and delivers an MPEG2
compliant transport stream. It contains a single 10-bit
Figure 1 - System Diagram
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Zarlink, ZL and the Zarlink Semiconductor logo are trademarks of Zarlink Semiconductor Inc.
Copyright 2005, Zarlink Semiconductor Inc. All Rights Reserved.
ZL10210
Data Sheet
analog-to-Digital Converter (ADC), a digital QAM demodulator and Forward Error Correcting (FEC) decoder. The
QAM demodulator supports QAM constellations 16 to 256. Both the QAM demodulator and the FEC are DVB and
ITU-T J.83 annex A/C compliant.
Figure 2 - ZL10210 Functional Diagram
The ADC uses a fixed sample rate greater than four times the maximum symbol rate. Hence for 1 to 9 MBaud appli-
cations, the signal has to be sampled at a frequency around 36 MHz. The spectrum of the analog signal being
sampled may be located at near-zero IF (e.g. centered at 9 MHz) or it may be located at a conventional IF such as
36.2 MHz or 43.5 MHz.
First consider the case of IF sampling a 1 to 7 MBaud QAM signal centered at 36.2 MHz intermediate frequency.
The sampling frequency chosen for this application is 28.9 MHz. This sampling process will fold the 36.2 MHz IF
spectrum to one centered at 7.3 MHz.
Second consider the case of IF sampling a 1 to 6 MBaud QAM signal centered at 43.5 MHz IF. The sampling
frequency chosen for this application is 25 MHz. This sampling process will result in a QAM spectrum centered at
6.5 MHz.
In the second case the sampling process results in spectral inversion. Even in first case the IF spectrum may be
spectrally inverted. However, spectral inversion is not an issue with ZL10210 since it automatically detects and
corrects for this in the digital domain.
The digital signal is first mixed down to baseband. However, as a result of tuning errors this signal will not be
centered at zero frequency. ZL10210 has an automatic frequency control (AFC) loop that can track out tuning
errors and hence in the tracking phase this signal will be centered at zero frequency. The AFC loop can typically
compensate for +/-350 kHz frequency offsets. Larger offsets can be corrected by programming on-chip registers.
The baseband signal is filtered to reduce the effect of adjacent channels. Additional on-chip digital filtering is
provided for low symbol rate applications. For example, it is possible to demodulate and decode a 1 MBaud QAM
signal using only one external 8 MHz SAW filter.
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Zarlink Semiconductor Inc.
ZL10210
Data Sheet
ZL10210 has complete blind acquisition capability. It can automatically search and lock on to any QAM constel-
lation in the set 16, 32, 64, 128 and 256. It can compensate for spectral inversion. It can also automatically acquire
a symbol rate in the range 1 to 7 MBaud correcting for any tuning errors and adapting the filter bandwidths to signal
bandwidth. All these functions are implemented using a sophisticated built-in control state machine with no software
intervention.
The symbol-spaced equalizer in the ZL10210 is designed to acquire the QAM signal in blind mode, i.e., with no
training sequence, and then to track the signal in the decision feedback mode. The equalizer has a feed-forward
segment and a feedback segments. The tap partitioning between feed-forward and feedback is fully programmable.
The symbol timing and phase recovery functions with the ZL10210 are fully digital. The timing recovery phase
locked loop has a built in timing sweep to enable the ZL10210 to lock on to unknown symbol rates. The phase
recovery loop has been optimised to overcome phase noise degradation caused by typical tuners.
The ZL10210 QAM demodulator has built in control mechanisms to overcome signal degradation due to impulse
noise in cable systems. The most significant bits of the demodulated I/Q symbols are differentially decoded to
remove multiples of 90 degree phase ambiguity in demodulation. The QAM symbols are then demapped into a bit
stream, using the constellation definitions provided by DVB and ITU-T. The number of bits per symbol is eight for
QAM-256, seven for QAM-128, six for QAM-64, five for QAM-32 and four for QAM-16.
The bitstream is aligned into bytes and then into 204-byte frames by the Frame Alignment Unit. These frames are
deinterleaved as defined by DVB to improve the resilience of the system to error bursts. The (204,188) Reed-
Solomon decoder, which follows the deinterleaver, can correct up to eight byte-errors per frame. This also
generates an uncorrectable error flag for blocks with more than eight byte-errors. In addition, the ZL10210 Reed-
Solomon decoder keeps a count of the number of uncorrectable blocks and the number of bit errors corrected. The
former will give an indication on the quality of the MPEG output and the latter provides the Bit Error Rate in QAM
demodulation.
The decoder packets are then descrambled to reverse the energy dispersal function introduced by the transmitter.
The output of the device is a stream of regularly spaced MPEG packets. The MPEG byte clock frequency is
automatically adapted to be the minimum needed for a given symbol rate and QAM constellation. Alternatively the
MPEG bytes can be clocked out using an externally provided byte clock. There is also an option for bit-serial
output.
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Zarlink Semiconductor Inc.
ZL10210
Data Sheet
Figure 3 - Typical ZL10210 Application
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Zarlink Semiconductor Inc.
ZL10210
1.0
1.1
Data Sheet
Pin & Package Details
Pin Outline
Figure 4 below shows the pin functions of the ZL10210.
Figure 4 - Pin Outline
1.2
Pin
1
2
3
4
5
6
7
8
Pin Allocation
Function
Vdd
CVdd
Gnd
SADD3
SADD2
IRQ
CVdd
Gnd
Pin
17
18
19
20
21
22
23
24
Function
GPP0
SADD4
RESET
SLEEP
PLLTest
PLLVdd
Gnd
XTI
Pin
33
34
35
36
37
38
39
40
Vdd
RFLev
Gnd
CVdd
SADD1
SADD0
AGC2/GPP1
AGC1
Function
Pin
49
50
51
52
53
54
55
56
Function
MDO0
MDO1
MDO2
MDO3
MDO4
MDO5
Vdd
Gnd
Table 1 - Pin Names - numeric
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