Product specification
Supersedes data of 1999 Jun 21
File under Integrated Circuits, IC02
1999 Dec 14
Philips SemiconductorsProduct specification
QPSK transmitterTDA8050
FEATURES
• Programmable gain
• PLL controlled carrier frequency
• 3-wire transmission bus
• 5 V supply voltage.
APPLICATIONS
• QPSK modulation.
GENERAL DESCRIPTION
The QuadraturePhaseShift Keying(QPSK) transmitter is
a monolithic bipolar IC dedicated for quadrature
modulation of the I and Q signals. It includes:
• Two double-balanced mixers
• Symmetrical Voltage Controlled Oscillator (VCO) with
0 to 90 degree signal generation for modulation
• Phase-Locked Loop (PLL) for IF frequency control
• Conversion mixer
QUICK REFERENCE DATA
• PLL for RF frequency control
• Gain controlled output amplifier
• 3-wire bus and an output buffer.
Two PLLs are incorporated, the first PLL includes:
• Fixed main divider
• Crystal oscillator and its programmable reference
divider
• Phase/frequency detector combined with afixed charge
pump.
The second PLL includes:
• Divide-by-four preamplifier
• 12-bit programmable divider
• Crystal oscillator and its programmable reference
divider
• Phase/frequency detector combined with a ‘clever’
chargepump which drivesthe tuning amplifier,including
9 V output.
SYMBOLPARAMETERMIN.TYP.MAX.UNIT
V
CC
f
c
V
o(max)
f
xtal
f
ref(MOD)
f
step
T
amb
supply voltage4.755.005.25V
output centre frequency5−40MHz
maximum output level−55−dBmV
crystal frequency1−4MHz
reference frequency for modulator synthesizer−250−kHz
frequency step size for convertor synthesizer50−500kHz
operating ambient temperature0−70°C
ORDERING INFORMATION
TYPE
NUMBER
NAMEDESCRIPTIONVERSION
PACKAGE
TDA8050TSO32plastic small outline package; 32 leads; body width 7.5 mmSOT287-1
1999 Dec 142
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1999 Dec 143
BLOCK DIAGRAM
Philips SemiconductorsProduct specification
QPSK transmitterTDA8050
I_IN
I_INC
Q_IN
Q_INC
CLK
DATA
EN
LOCK
5
6
7
8
14
15
16
23
CHARGE
CP_MOD
DVCC13DGND
PUMP
RF_OUTC
AVCC1
18
AGND1
26
9
RF_OUT
252428
RF_INCIF_FILTC
RF_INIF_FILT
27
30 31
SW_CAP
MODULATORCONVERTER
×
Σ
×
×
3-WIRE BUS TRANCEIVER
DIGITAL
PHASE
COMPARATOR
PROGRAMMABLE
FIXED
MAIN DIVIDER
REF DIVIDER
90°0°
1/2
TDA8050
1012111722 21
TKAMOD
TKBMODTKACONV
OSC_INTKBCONV
DAC
PROGRAMMABLE
MAIN DIVIDER
PROGRAMMABLE
REF DIVIDER
AVCC2
32
DIGITAL
PHASE
COMPARATOR
2019
TUNECONVCP_CONV
AGND2
29
PROGRAM-
MABLE
CHARGE
PUMP
4
1
OUTEN
3
BUF_OUTC
2
BUF_OUT
FCE181
handbook, full pagewidth
Fig.1 Block diagram.
Philips SemiconductorsProduct specification
QPSK transmitterTDA8050
PINNING
SYMBOLPINDESCRIPTION
OUTEN1output enable
BUF_OUT2output amplifier balanced output
BUF_OUTC3output amplifier balanced output
AGND24converter analog ground 2
I_IN5I balanced input
I_INC6I balanced input
Q_IN7Q balanced input
Q_INC8Q balanced input
AGND19modulator analog ground 1
TKAMOD10 modulator VCO tank circuit input 2
TKBMOD11 modulator VCO tank circuit input 1
CP_MOD12 modulator charge pump output for
PLL loop filter
DVCC13digital supply voltage
CLK14 3-wire bus serial control clock
DATA15 3-wire bus serial control data input
EN16 3-wire bus serial control enable
OSC_IN17 crystal oscillator input
DGND18 digital ground
CP_CONV19converter charge pump output for
PLL loop filter
TUNECONV 20 tuning voltage output for converter
VCO
TKBCONV21converter VCO tank circuit input 1
TKACONV22converter VCO tank circuit input 2
LOCK23 lock detect signal
IF_FILT24IF balanced output to filter
IF_FILTC25 IF balanced output to filter
AVCC126 modulator analog supply voltage
RF_OUTC27 RF balanced output to filter
RF_OUT28 RF balanced output to filter
AVCC229 converter analog supply voltage
RF_IN30RF balancedinput to programmable
The I and Q are balanced analog signals at a level of
400 mV (p-p). These are mixed by two double balanced
mixers with the output signal generated by a first local
oscillator providing the modulated signal.
The modulated signal is then filtered by an IF filter. This
filteredsignal together with asignalgenerated by asecond
local oscillator is converted by a balanced mixer to
produce the QPSK signal.
TheQPSK signal isamplified by again controlled amplifier
to a level suitable for transmission. The gain of the
controlled amplifier is buscontrolled and this amplifier can
be disabled when not transmitting to provide signal
attenuation.
The amplified signal is applied to an on-chip amplifier
having two balanced outputs (open collector) linked totwo
chip resistors (values 150 Ω), and 9 V. The balanced
outputs are designed to drive a 2 : 1 transformer
(Siemens V944) with a 75 Ω load giving an output level
of 55 dBmV.The output frequencyrange of the transmitter
is 5 to 40 MHz.
The frequency of the first local oscillator operates at twice
the frequency (i.e. 280 MHz) fixed by a Phase-Locked
Loop (PLL) implemented in the circuit.
Thefrequencyof the second localoscillatoroperatesin the
bandwidth 145 to 180 MHz and programmable due to a
PLL implemented in the circuit.
The VCO of both first and secondlocal oscillatorsrequires
an external LC tank circuit with two varicap diodes.
The data to the PLL is loaded in bursts framed by the
signal EN. Programming rising clock edges and their
appropriate data bits are ignored until EN goes active
(LOW). The internal latches are updated with the latest
programming data when EN returns inactive (HIGH).
The last 14 bits are stored in the programming register.
No check is made on the number of clock pulses received
during the time programming is enabled. A wrong active
clock edge will be generated causing a shift of data
bits, if EN goes HIGH while CLK is still LOW. At power
up, EN should beHIGH. The lock detector output LOCK is
HIGH when both PLLs are in lock.
The main divider ratio and the reference divider ratios are
provided via the serial bus. A control register controls the
Digital-to-Analog Converter (DAC), the output amplifier
and the charge pump currents (Tables 1, 2 and 3).
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
SYMBOLPARAMETERMIN.MAX.UNIT
V
CC
t
sc
V
max
V
o(tune)
V
o(buf)
P
tot
T
amb
T
stg
T
j(max)
supply voltage−0.3+6.0V
short-circuit time (every pin to VCCor GND)−10s
voltage on all pins except BUF_OUT, BUF_OUTC and TUNECONV−0.3V
CC
V
output tuning voltage−0.3+30V
output buffer voltage on pins BUF_OUTand BUF_OUTC−10V
maximum power dissipation−800mW
operating ambient temperature070°C
storage temperature−40+150°C
junction temperature−150°C
1999 Dec 145
Philips SemiconductorsProduct specification
QPSK transmitterTDA8050
THERMAL CHARACTERISTICS
SYMBOLPARAMETERCONDITIONSVALUEUNIT
R
th(j-a)
HANDLING
Human Body Model (HBM): The IC pins withstand 2 kV except pins 27 and 28 (1750 V).
Machine Model (MM): The IC pins withstand 100 V.
CHARACTERISTICS
Measured in application circuit (see Fig.9) with the following conditions: V
values; unless otherwise specified.
thermal resistance from junction to ambientin free air63K/W
=5V; T
CC
=25°C; all AC units are RMS
amb
modulator analog supply voltage4.7555.25V
modulator analog supply current−41−mA
converter analog supply voltage4.7555.25V
converter analog supply current−48−mA
buffer output supply current−44−mA
digital supply voltage4.7555.25V
digital supply current−22−mA
tuning supply voltage−−9V
input DC levelover the complete range of
−0.5VCC−V
temperature
signal input level (balanced)
indicative−400500mV
(peak-to-peak value)
I and Q maximum input frequencyindicative−10−MHz
differential input impedance−4.4−kΩ
1 dB amplifier bandwidthindicative−10−MHz
output centre frequency−−140MHz
LO suppressionsee Fig.3−−28−dBc
differential output impedance−1.8−kΩ
oscillation frequency VCO−−280MHz
1999 Dec 146
Philips SemiconductorsProduct specification
QPSK transmitterTDA8050
SYMBOLPARAMETERCONDITIONSMIN.TYP.MAX.UNIT
Converter output
V
o
output levelfi= 30 MHz; V
at I and Q inputs
∆V
o
output flatnessfi= 5 to 40 MHz;
V
= 100 mV at I and Q
i(dif)
inputs
f
c
Z
o(dif)
output centre frequency5−40MHz
differential output impedance−150−Ω
IM33rd-order intermodulation distortion see Fig.4−−−35dBc
H
2
2nd-order harmonic of 5 to 40 MHz
signal
fi= 10 to 80 MHz;
V
= 100 mV at I and Q
i(dif)
inputs
H
3
3rd-order harmonic of 5 to 40 MHz
signal
fi= 15 to 120 MHz;
V
= 100 mV at I and Q
i(dif)
inputs
S
o
mixer spurious outputs of
5 to 40 MHz signal
fi= 5 to 40 MHz;
V
= 100 mV at I and Q
i(dif)
inputs
Converter voltage controlled oscillator
f
osc(min)
f
osc(max)
minimum oscillation frequency−−145MHz
maximum oscillation frequency180−−MHz
Programmable gain and output buffer; note 1
Z
i(dif)
differential input impedance−5.6−kΩ
∆Goutput level step size−−2dB
∆Buf
o
output level adjust rangeVi= 30 dBmV sine wave;
40 MHz at pin
RF_IN and RF_INC;
DAC = 0 to 31
V
∆V
o
o
output level−55−dBmV
output flatnessfi= 5 to 40 MHz;