Second-generation transceiver enables 3G TD-SCDMA handsets

Second-generation transceiver enables 3G TD-SCDMA handsets

CMOS RF transceiver adds dual-band and HSDPA support and simplifies 3G radio design by eliminating need for costly SAW filters

Measuring 6 x 6 mm, the Othello-3T AD6552 second-generation radio is designed specifically for the 3G TD-SCDMA standard and complements all of the company’s TD-SCDMA baseband chipsets, including SoftFone-LCR and SoftFone-LCR+. The device simplifies the development of the radio section of 3G wireless handsets by eliminating the SAW filters that are usually needed in the transmit path while integrating virtually all of the necessary components for a handset radio design (VCOs, tank circuits, loop filters and power management)—a 40% reduction in component count over the previous two-chip Othello-W single-band radio for TD-SCDMA.

The receiver section includes high-performance single-ended LNAs covering the 1,900- and 2,000-MHz bands. A direct-down-converting quadrature mixer driven by an on-chip fractional-N PLL synthesizer delivers baseband I and Q signals to a variable-gain amplifier and programmable low-pass filter stages with dc offset correction. The transmitter section consists of a fractional PLL synthesizer, a high-performance variable-gain amplifier, and quadrature modulator driving a common wideband output stage, as well as a true-rms RF power detector and on-chip D/A converter for power amplifier control. (Call company for pricing—samples available now.)

Analog Devices , Wilmington , MA
Technical Support 800-262-5643

http://www.analog.com