New RF Synthesizer with Integrated VCOs from STMicroelectronics Stretches Out to 5GHz

Frequency synthesizers form the basis of most radio designs, and their performance largely affects the operation of the overall system. The leading requirements for signal-generating components in today’s communications equipment include minimized phase noise and broadband frequency coverage.

To address these requirements, ST’s STW81103 exhibits the industry’s best phase-noise performance for single-chip RF synthesizers, with measured values of 0.27 degrees RMS (Root Mean Square) at 1.16GHz, 0.6 degrees RMS at 2.33GHz, and 1.5 degrees RMS at 4.67GHz with a frequency step of 200kHz. Outstanding suppression of random frequency fluctuations in a signal provides more design margin, and the low phase noise also satisfies the stringent requirements of system manufacturers for minimized bit-error rates in voice and data transmission.

In addition to broad spectrum coverage of up to 5GHz, the STW81103’s embedded VCOs with automatic center-frequency calibration provide outstanding multi-band functionality. A single device spans frequency bands from 625 to 762.5MHz, 1087.5 to 1525MHz, 2175 to 3050MHz, and 4350 to 5000MHz, allowing wireless system suppliers to use the device in wideband and multi-band applications. Among competing solutions, ST’s family of integrated RF synthesizers needs just three devices (STW81101, STW81102, and STW81103) to cover the largest frequency range, from 625MHz to 5GHz.

Whereas existing solutions for microwave frequencies require discrete phase-locked loop (PLL) devices and voltage-controlled oscillators (VCOs), ST’s single-chip approach reduces both the Bill-of-Materials and footprint by as much as 70%. Other benefits of the monolithic synthesizer include an increase in device reliability and simplified supply chain for equipment manufacturers.

“ST’s unparalleled combination of a world-class RF technology, solid design skills, and leading-edge components results in dramatic savings in material costs and board space, which are the key concerns of wireless equipment manufacturers today,” said Guillaume Pertinant, RF technical marketing manager at ST’s Communication Infrastructure Division. “With the broadest band-coverage in the market, our single-chip synthesizers are set to spearhead the development of cost-efficient applications in the microwave range.”

Pin-to-pin compatible with other members of ST’s STW8110x family, the STW81103 is supplied in VFQFN-28 lead-free packages. Samples are available now, with volume production slated for early Q1 2008 at a price of $5.39 in quantities of 1, 000 pieces.

Customers can order evaluation kits that include the STWPLLSim software, a powerful simulation tool, which enables very fast and accurate PLL design and optimization of the use of the STW8110x devices.

A leading supplier of advanced products to the wireless industry, STMicroelectronics offers a full spectrum of digital and RF devices for wireless infrastructure applications, covering most functions in cellular base stations and wireless broadband systems. From dedicated solutions (ASIC) to optimized standard products (ASSP), ST’s wireless infrastructure portfolio, defined in co-operation with leading telco manufacturers, ensures the highest level of integration and flexibility.