Single-Chip Solution Reduces Satellite LNB Size Up To 30%

Integrating all bias, control and power management functions into a single chip, the ZNXB series of low noise block (LNB) satellite controllers help achieve size reductions of up to 30%. Three LNB controllers have been introduced: The ZXNB4100 negative voltage bias and ZXNB4200 zero voltage bias devices for single universal LNBs with FET switching topologies, and the ZXNB2200 for C-band LNB designs. Offered in 16-pin 3mm x 3mm and 4mm x 4mm QFN packages, the controllers require just three external components to function, 10 less than alternative single universal LNBs, and 20 less than typical C-band LNB designs, the company says. The controllers provide biasing for up to three GaAS FET LNA stages and an active mixer. To optimize system performance, the drain current of LNA FETs and the active mixer is user selectable, via an external reference resistor. An on-board voltage detector enables the required polarization channel, while a 22 kHz tone detector—with integrated filter and signal rejection—handles switching between high and low band oscillators. Additionally, the ZXNB controllers are “self powering,” bringing the voltage regulator into the LNB controller chip for the very first time. The devices are able to provide a temperature compensated, high current output voltage sufficient to power all parts of the LNB circuit, such as IF amplifier stages. This protects against overload, over-temperature and installation errors. The ZXNB4100 and ZXNB4200 are priced at $1.78 each/1,000 in a 3 mm x 3 mm QFN package, while the ZXNB2200 is $1.63 each/1,000. ZETEX SEMICONDUCTORS, Hauppauge, NY. (631) 360-2222.