Texas Instruments - Low-power synthesizer features frequency-shift keying modulation (LMX2571)

LMX2571 is a new product of Texas Instruments. It is a low power, high performance, wideband PLLatinum RF synthesizer, integrating delta-sigma fractional N PLL, multi-core voltage controlled oscillator (VCO), programmable output. Divider and two output buffers. The maximum operating frequency of the VCO core is 5.376GHz, resulting in a continuous output frequency range from 10MHz to 1344MHz. This synthesizer can also be used with an external VCO. For this purpose, a dedicated 5V charge pump and an output voltage divider are provided for this configuration. A novel programmable multiplier is also integrated to help improve spurs, even if the system falls on integer boundaries, the system can use it. The output has an integrated SPDT switch that can be used as a send / receive switch in FDD radio applications. Both outputs can also be turned on simultaneously to provide 2 outputs. The LMX2571 supports direct digital FSK modulation through programming or pins. Support discrete level FSK, pulse shaping FSK and analog FM modulation. The company says that even with an external VCO with a narrow-band loop filter, a new FastLock technology can be used to allow users to jump from one frequency to another in less than 1.5ms.