Wideband RF synthesiser attains low in-band noise and integrated jitter

The Texas Instruments LMX2820 is a high-performance, wideband synthesiser that can generate any frequency in the range of 43.75MHz to 22.4GHz. The high-performance PLL with a figure of merit of –236dBc/Hz and high phase detector frequency is able to attain extremely low in-band noise and integrated jitter. The high-speed N-divider has no pre-divider, therefore, significantly decreasing the amplitude and number of spurs. There is also a programmable input multiplier to mitigate integer boundary spurs.

The device enables users to synchronise the output of multiple devices and also allows applications that require a deterministic delay between input and output. The fast calibration algorithm greatly diminishes the VCO calibration time to under 5µs, allowing systems needing fast frequency hopping. The device can generate or repeat SYSREF that is compliant to the JESD204B standard, providing for its application as a low-noise clock source for high-speed data converters. This synthesiser can also be employed with an external VCO. A direct PFD input pin is offered to support offset mixing for low spurious transmission.

The device operates from a single 3.3V supply and includes integrated LDOs that remove the requirement for onboard low-noise LDOs.