TDA8042M

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 of the TDA8042M 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 of the TDA8042M 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.