wirelessZONE Products for the week of June 14, 2010

Peregrine Semiconductor Says…

PE33361/PE33631: PLL Frequency Synthesizers Offer Leading Phase Noise Performance
European-flow UltraCMOS RF ICs deliver -216 dBc/Hz with ultra-low power

Peregrine Semiconductor Corporation, a leading supplier of high performance RF CMOS and mixed-signal communications ICs, announced two new devices in its widely popular Phase-Locked Loop (PLL) Frequency Synthesizer family. These UltraCMOS RFIC devices fulfill the need for low-power, ultra-low phase noise, multiple-way programmable PLL solutions for capability of the military, broadband cable infrastructure, and wireless infrastructure markets. The PE33361 Integer-N PLL and the PE33631 Delta-Sigma Modulated (DSM) Fractional-N PLL are the first devices to be completely developed through Peregrine’s recently announced European design and manufacturing flow. The PLLs operate over a wide frequency range 50 MHz to 3.5 GHz, providing a high-performance RF solution for demanding applications such as cellular base stations, CATV set-top boxes, test and measurement equipment, WiMax-based communications systems and point-to-point radios where system scalablility is key to improving designs.

The new PLL devices deliver market-leading RF performance and frequency synthesis up to 3.5 GHz with -216 dBc/Hz phase noise (normalized), and ultra-low power consumption of 40 mA (PE33631) and 45 mA (PE33361) at 3.3V. Both PLL devices offer flexible programming options: the PE33361 PLL is programmable through serial, parallel and direct mode access; the PE33631 PLL is programmable through serial and direct mode access.

EN-Genius Says…

We will discuss the PE33631 here, because it is the more complicated of the two product announcements, but both show high performance and imaginative architecture.

The PE33631 is a ∆-∑ (delta-sigma) modulated fractional-N frequency synthesizer with operation out to 3.5 GHz. It uses a divide-by-10/11 dual modulus prescaler on the VCO input depending on the modulus select value – which can be bypased – driving a main 9-bit counter to a phase detector. The other side of the phase detector is driven by a latch system using a primary 21-bit latch and a pair of secondary and auxiliary 20-bit latches. The secondary latch drives the main counter and a secondary reference (R) 6-bit counter while the auxiliary latch drives the modulator and the main counter. The delta-sigma modulator modulates a separate A counter (for the modulus select logic) outputs to provide the required fractional step and aids in producing fine frequency resolution as well as controlling fractional spurs. Data are written into the internal registers using the three-wire interface.

The phase (frequency) detector generates up- and down-frequency control signals.

Counter values can be either hard-wired or programmed through a serial interface The frequency selectivity is the ratio of the comparison frequency divided by 2e18.

The input level range for frequencies up to 3.2 GHz is -5 dBm up to +5 dBm (or 0 dBm to +5 dBm up to 3.5 GHz) with the main divider operating from 50 MHz to 300 MHz, the reference divider operating at a maximum of 100 MHz, with a phase detector comparison frequency of 50 MHz. A lock detect output is also provided which can be either a NAND or AND of the phase detector outputs.

Phase noise performance is extremely good with numbers (at 1.9 GHz) of low to high -80s dBc/Hz at 100 Hz offsets, about -100 dBc/Hz at 10 kHz offsets, and falling to about -140 dBc/Hz at 1 MHz offsets.

With a nominal 3.3 V supply rail the typical quiescent current is 40 mA with the prescaler enabled and 15 mA with the prescaler disabled. ESD tolerance is 1000 V HBM.

The low phase noise and the exceptionally-low quiescent currents of these two synthesizers show the quality of the UltraCMOS process. Both parts are derived from earlier 20 MHz comparison components, such as the PE3336, with the PE33631 adding direct programming for the first time. The new products will do exceptionally well in roles as varied as cellular basestations, CATV, and test & measurement applications.

The PE33361 is in production in QFN-48 and the PE33631 in QFN-64 with pricing at $11.52 and $12.80, respectively, both in 25-k piece lots.

Data Sheet PE33631