1997 Apr 11

2

Philips Semiconductors

Product specification

Quadrature demodulator

TDA8042M

FEATURES

• 5 V supply voltage

• Internal voltage reference

• 350 to 650 MHz input frequency range

• On-chip 0° and 90° phase shifter

• Symbol rate up to 45 Msymbols/s

• High input sensitivity

• Built-in voltage stabilizer

• AGC amplifier with 21 dB control range

• AGC detector.

APPLICATION

• Binary Phase-Shift Keying (BPSK) and Quadrature

Phase-Shift Keying (QPSK) demodulation.

GENERAL DESCRIPTION

The TDA8042M is a monolitic bipolar IC dedicated for

BPSK and QPSK demodulation. It is designed to be used

together with the TDA8043 as part of a complete

BPSK/QPSK satellite demodulator and decoder.

The bandwidth of the TDA8042M allows symbol rates up

to 45 Msymbols/s. It includes two matched mixers, an IF

gain controlled amplifier, a symmetrical oscillator, a 0

°/90°

phase shifter, two low-pass filters and two matched

baseband amplifiers.

The high input sensitivity makes interfacing with various

sources easy. The input sensitivity can be adjusted by

means of an internal AGC amplifier.

The oscillator operates at half the IF frequency. The local

oscillator signal driving the mixers is made by doubling the

oscillator frequency by an internal frequency multiplier.

The oscillator frequency can be set by the appropriate

external LC tank circuit. The internal wideband phase

shifter provides two oscillator signals which are

90 degrees out of phase to drive the mixers.

An AGC detector at the I and Q outputs makes it possible

to keep the I and Q signals at a constant level to drive the

analog-to-digital converters of the TDA8043.

QUICK REFERENCE DATA

ORDERING INFORMATION

SYMBOL

PARAMETER

CONDITIONS

MIN.

TYP.

MAX.

UNIT

supply voltage

4.75

5.0

5.25

V

supply current

54

67.5

81

mA

operating input level

−

57

−

dB

µV

RF input signal frequency

350

−

650

MHz

I and Q output voltage (peak-to-peak value)

−

0.8

−

V

phase matching error between I and Q channels

−

0.7

2

deg

gain matching error between I and Q channels

−

0.15

0.8

dB

∆G

tilt

gain tilt error between I and Q channels

−

0.3

0.5

dB

TYPE

NUMBER

PACKAGE

NAME

DESCRIPTION

VERSION

TDA8042M

SSOP20

plastic shrink small outline package; 20 leads; body width 4.4 mm

SOT266-1