LTC6947IUFD#PBF

Clock Generators, PLLs, Frequency Synthesizers Overview

The LTC6947IUFD#PBF is a fractional-N phase-locked loop synthesizer operating from 350MHz to 6GHz. It integrates a reference divider, phase-frequency detector, ultralow noise charge pump, and a 4th-order delta-sigma modulator for an 18-bit fractional denominator. The device features a programmable VCO output divider (1–6) and a differential output buffer with adjustable power from –4.3dBm to +4.5dBm. Key electrical specifications include a normalized in-band phase noise floor of –226dBc/Hz and a wideband output phase noise floor of –157dBc/Hz. All settings are managed via an SPI-compatible serial interface.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Ultralow noise performance with –226dBc/Hz normalized in-band phase noise floor
• Advanced 4th-order delta-sigma modulator eliminates integer boundary spurs
• Programmable output divider range of 1 through 6 with 50% duty cycle
• User-programmable output power from –4.3dBm to +4.5dBm

Clock Generators, PLLs, Frequency Synthesizers Applications

• Wireless basestations (LTE, WiMAX, W-CDMA, PCS)
• Broadband wireless access systems
• Microwave data links
• Military and secure radio communications
• Test and measurement equipment

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the ordering suffix #PBF indicates lead-free finish and tape and reel packaging. Confirm the I suffix corresponds to the industrial temperature range of –40°C to 105°C. Ensure the UFD package designation matches the 28-lead 4mm x 5mm plastic QFN form factor required for the design.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this component when low integrated phase noise and wide loop bandwidths are critical. The 18-bit fractional denominator allows fine frequency resolution without discrete modulator spurs. Verify that the external VCO operates within the 350MHz to 6GHz input range and that the system requires an SPI-controlled PLL architecture.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This part belongs to the Linear Technology (now Analog Devices Inc.) LTC6947 family of high-performance fractional-N synthesizers. The IUFD#PBF variant specifically denotes the industrial temperature grade housed in a compact QFN package, designed for space-constrained RF front-end applications requiring precise frequency synthesis.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.