TDA8050

Features:

· Programmable gain
· PLL controlled carrier frequency
· 3-wire transmission bus
· 5 V supply voltage.




Application

· QPSK modulation.




Pinout






Specifications

SYMBOL	PARAMETER	MIN.	MAX.	UNIT
VCC	supply voltage	-0.3	+6.0	V
tsc	short-circuit time (every pin to VCC or GND)	-	10	S
VMAX	voltage on all pins except BUF_OUT, BUF_OUTC and TUNE_CONV	-0.3	VCC	V
V(tune)	output tuning voltage	-0.3	+30	V
VO(buf)	output buffer voltage on pins BUF_OUTand BUF_OUTC	-	10	V
Ptot	maximum power dissipation	-	800	mW
Tamb	Operating ambient temperature	0	70
Tstg	storage temperature	-40	+150
Tj(max)	maximum junction temperature	-	150

Description

The Quadrature Phase Shift Keying (QPSK) transmitter is a monolithic bipolar IC dedicated for quadrature modulation of the I and Q signals. TDA8050 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
` 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 a fixed 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' charge pump which drives the tuning amplifier, including
9 V output.