1997-01-27 , E/DS-349/120

Silicon RF power modules from Philips Semiconductors provide designers with ready-made power amplifiers for AMPS/ETACS cell-phones.

The BGY122A and BGY122B 1.2-Watt UHF Amplifier Modules require no external components to make them work. As a result, they considerably shorten the time-to-market for new cell-phone designs by dramatically reducing the amount of design-in effort required. Their performance, however, matches that of more complex and expensive GaAs solutions.

"Existing discrete component and GaAs MMIC solutions require very careful design and layout to ensure consistent performance," commented International Product Marketing Manager Wout Bijker, "but because the BGY122A and BGY122B are fully integrated, pre-tested parts, we can virtually guarantee our customers that their designs will work first time."

In addition to being the easiest of modules to design in, the BGY122A and BGY122B are also the smallest 1.2-W modules currently on the market. Their SOT388A packages have a pc board footprint of 17 x 12 mm and a mounting height of 2 mm, which together with no requirement for peripheral circuitry makes them ideal for use in light-weight slim-line cell-phones.

The BGY122A covers the 824 MHz to 849 MHz (AMPS) band and the BGY122B covers the 872 MHz to 905 MHz (E)TACS band. Both modules provide a minimum power gain of 27.8 dB, which means that only 2 mW of RF drive is required to deliver an output power of 1.2 W into a 50 ohm antenna load. This eliminates the need for a separate driver stage. To make things even easier, the BGY122A and BGY122B operate from a single 4.8 V supply and require no external bias circuitry or power-control switches.

Typical operating efficiencies of 55% keep power dissipation to a minimum, thereby improving device reliability. Standby current consumption, a particularly important parameter in hand-held battery-powered equipment, is typically less than 1 µA.

The BGY122A and BGY122B are 3-stage amplifiers constructed using high-performance npn silicon planar transistor chips mounted on a metallized ceramic substrate that provides extremely good thermal conductivity to the mounting base. Production volumes of both modules are available now.