U6102B

The U6102B has the following features including Frequency range from 390 to 520 MHz;Two unbalanced switchable inputs;High input sensitivity;AGC control range -35 dB;Internal AGC detector;Additionally external gain control and output level setting possible;Electrostatic protected according to MIL STD 883;SS020 small outline package.

The  U6102B  is  a  monolithic  integrated  circuit in TEMIC's UHF 5 technology for Sattelite Digital Video Broadcasting (DVBS) and other digital direct sattelite service applications. The circuit of U6102B operates in a wide frequency range and in a large input level range. Incorporated  are  two  orthogonal  mixer  stages,  (precise phase-matched by a control loop), a gain controlled IF amplifier of high input sensitivity with two switchable isolated inputs and an AGC system for tuner and IF level control. Alternatively the output level may be controlled automatically, e.g., via the channel decoder AGC signal output. The local oscillator operates at IF input frequency.The oscillator signal is internally doubled and again divided to generate the orthogonal mixer driving signals. The oscillator is designed for direct driving a SAW tank circuit.The input signal of U6102B is connected via two single ended constant gain amplifiers with selectable inputs to a gain controlled  amplifier.  The  differential output  signal remains of constant amplitude to provide-behind splitting up-optimized dynamic operation points for a pair of identical mixers. The mixer stages are driven by two orthogonal oscillator signals, to generate the I- and Q-components.

To avoid fast system lock in time and driving the A/D converters with defined output levels, in one channel the output signal of U6102B will be peak level detected and in an internally loop level controlled. So the output signal amplitudes are independent of frequency and characteristic of the QPSK modulation. The output level of U6102B can be set via an external potentiometer (or at two fixed levels by pin programming) according to the actual application.External loop control is provided by a channel decoder generated AGC signal.