TDA8046 Datasheet, PDF (3/48 Pages) NXP Semiconductors – Multi-mode QAM demodulator

Philips Semiconductors
Multi-mode QAM demodulator
Product specification
TDA8046
1 FEATURES
• Different modulation schemes: 4, 16, 32,
64 and 256-QAM
• Digital demodulator and square root raised cosine
Nyquist filter with roll-off of 15% or 20%
• High performance adaptive equalizer (no training
sequence needed)
• Digital detectors for generation of required control
voltages for carrier recovery, clock recovery and AGC
• Digital-to-analog converters and operational amplifiers
allowing high flexibility for selection of the (PLL) loop
time constants
• High maximum symbol rate (r_s) of 7 Msymbols/s
• Input format: Straight binary or 2’s complement
(up to 9 bits, TTL compatible)
• Output format: 8-bit wide bus (CMOS compatible)
• I²C-bus interface to initialize and monitor the
demodulator. When no I²C-bus usage; 64-QAM,
20% roll-off factor in default mode
• 5 V peripheral and analog supply voltage
• 3.3 V core supply voltage
• Boundary scan test.
2 APPLICATION
Demodulation for digital cable TV and cable modem.
3 QUICK REFERENCE DATA
SYMBOL
V_DDD(core)
V_DDD
V_DDA
I_DDD(core)
I_DDD
I_DDA
r_s
IL
α
SNR_lock
PARAMETER
CONDITIONS
MIN.
core supply voltage
3.00
digital peripheral supply voltage
4.75
analog supply voltage
4.75
core supply current
digital peripheral supply current
analog supply current
symbol rate
implementation loss
Nyquist roll-off (programmable)
V_DDD(core) = 3.3 V; note 1 −
V_DDD = 5 V; note 1
−
V_DDA = 5 V; note 1
−
−
note 2
−
−
signal-to-noise ratio for locking a
21
64-QAM constellation
signal-to-noise ratio for locking a
27
256-QAM constellation
TYP. MAX.
3.30
3.60
5.00
5.25
5.00
5.25
100
−
14
−
16
−
−
7
0.7
−
15 or 20 −
−
−
−
−
UNIT
V
V
V
mA
mA
mA
Msym/s
dB
%
dB
dB
Notes
1. The supply currents are specified for the maximum symbol frequency.
2. The implementation loss (IL) of the demodulator is defined as the distance between the measured and theoretical
BER curve as function of signal-to-noise ratio at a BER = 10^−6 for a back-to-back measurement at the IF frequency.
This performance depends on the chosen loop parameters (see Application notes).
4 ORDERING INFORMATION
TYPE
NUMBER
TDA8046H
NAME
QFP64
PACKAGE
DESCRIPTION
plastic quad flat package; 64 leads (lead length 1.95 mm);
body 14 × 20 × 2.8 mm
VERSION
SOT319-2
1996 Nov 19
3