TDA8060ATS Datasheet, PDF (10/16 Pages) NXP Semiconductors – Satellite ZERO-IF QPSK down-converter

Philips Semiconductors
Satellite ZERO-IF QPSK down-converter
Product specification
TDA8060ATS
handbook, full pagewidth
50 Ω
RF
SOURCE
1.5 pF _RFB
1.5 pF _RFA
TDA8060ATS
IOUT
QOUT
high
impedance
probe
Vo (dB)
FCE414
50 Ω
RF
SOURCE
50 Ω Vi (dB)
Fig.5 Gain control diagram for asymmetrical RF input.
APPLICATION INFORMATION
Close attention should be paid to the design of the external
tank circuit of the VCO so that it covers the
920 to 2200 MHz frequency range. Both series 6 Ω
resistors kill all parasitic oscillations that could alter this
frequency range. The BB835 Siemens varicap diodes are
mentioned because they provide the highest C_max/C_min
ratio as well as the least parasitic elements in our
frequency range. The U-shaped inductance can be printed
with a total length of approximately 20 mm.
Filters LP1 and LP2 are not detailed in this data sheet
because their design only depends on the global system.
As the TDA8060ATS has been designed to be compatible
with DVB, DSS and Asian DVB, the cut-off frequencies
and the tolerance in group delay, the orders of the filters
cannot be globally established.
Nevertheless, the TDA8060ATS internally filters the
baseband at 100 MHz and the nominal levels at inputs and
outputs mentioned in the characteristics table should be
respected. The input impedance of LP1 and LP2 must
exceed 400 Ω to avoid signal distortion.
The converter outputs (pin IOUT and pin QOUT) must be
AC-coupled via the low-pass filter to the baseband
amplifiers inputs (pin IBBIN and pin QBBIN). Because of
the high impedance at pin IQBBIN, a 100 nF capacitor
gives a high-pass frequency of 160 Hz.
2000 Nov 10
10