TDA8040T Datasheet, PDF (2/16 Pages) NXP Semiconductors – Quadrature demodulator

Philips Semiconductors
Quadrature demodulator
Objective specification
TDA8040T
FEATURES
• +5 V supply voltage
• Bandgap internal reference voltage
• Low crosstalk between I (in-phase) and Q (quadrature)
channel outputs
• High operating input sensitivity
• High Carrier-to-Noise Ratio (CNR) of the VCO.
APPLICATIONS
• Quadrature Phase Shift Keying (QPSK) demodulation.
GENERAL DESCRIPTION
The TDA8040T is a monolitic bipolar IC dedicated for
quadrature demodulation.
It has been designed to operate in conjunction with the
TDA8041H to provide a complete QPSK demodulator.
The design of this circuit has been optimized to provide the
best quadrature accuracy necessary for digital receiver
applications and particularly for digital television.
The TDA8040T includes two matched mixers, an
RF amplifier, a symmetrical Voltage Controlled Oscillator
(VCO), a frequency divider and two matched amplifiers.
Two external filters are required for the baseband filtering.
The VCO requires an external LC tank circuit with two
varicap diodes. This oscillator operates at twice the
IF carrier frequency and can be used in a carrier recovery
AFC loop.
QUICK REFERENCE DATA
SYMBOL
V_CC
I_CC(tot)
V_i(RF)
f_i(RF)
V_olQ(p-p)
Eφ_(IQ)
E_G(IQ)
E_G(tilt)
α_ct(IQ)
IM3
PARAMETER
supply voltage
total supply current
operating input voltage level
RF input signal frequency
I and Q output voltage
(peak-to-peak value)
phase error between the
I and Q channels
gain error between the
I and Q channels
gain tilt error in the I and Q channels
crosstalk between the
I and Q channels
intermodulation distortion in the
I and Q channels
CONDITIONS
V_CC = 5 V
MIN.
4.5
70
64
10.7
−
−
−
−
30
40
TYP.
5.0
79
67
−
0.5
−
−
−
−
−
MAX.
5.5
90
70
150
−
UNIT
V
mA
dBµV
MHz
V
3
deg
1
dB
1
dB
−
dB
−
dB
ORDERING INFORMATION
TYPE NUMBER
TDA8040T
NAME
SO16
PACKAGE
DESCRIPTION
plastic small outline package; 16 leads; body width 3.9 mm
VERSION
SOT109-1
1996 Oct 08
2