LTC6948IUFD-2#PBF

Clock Generators, PLLs, Frequency Synthesizers Overview

The LTC6948IUFD-2#PBF is a fractional-N phase-locked loop synthesizer with an integrated voltage-controlled oscillator (VCO) from Analog Devices. It operates within a VCO frequency range of 3.08 GHz to 4.91 GHz and supports output frequencies up to 6.39 GHz via a programmable divider. The device features a 4th-order delta-sigma modulator for low spurious performance, an ultralow noise charge pump, and a reference input frequency up to 425 MHz. It utilizes a 28-lead QFN package and requires supply voltages of 3.3V for digital/RF sections and 5V for the VCO and charge pump.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrated VCO with frequency range of 3.08 GHz to 4.91 GHz
• Advanced 4th-order delta-sigma modulator eliminates discrete spurs
• Programmable output divider (1 to 6) extends frequency range
• Ultralow normalized in-band phase noise floor of –226 dBc/Hz

Clock Generators, PLLs, Frequency Synthesizers Applications

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

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify the specific -2 suffix corresponds to the 3.08 GHz to 4.91 GHz VCO range as defined in the ordering information table. Confirm the UFD package dimensions and exposed pad soldering requirements during assembly. Ensure supply rails match the specified 3.3V and 5V ranges for stable operation.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select this variant when the required VCO tuning range falls between 3.08 GHz and 4.91 GHz. The -2 option provides overlapping coverage with other variants if broader frequency agility is needed. Consider the output divider setting to achieve the final desired RF frequency while maintaining optimal phase noise performance.

Clock Generators, PLLs, Frequency Synthesizers Part Context

The LTC6948 family includes four variants differentiated by their internal VCO frequency ranges. The -1 covers 2.24–3.74 GHz, -2 covers 3.08–4.91 GHz, -3 covers 3.84–5.79 GHz, and -4 covers 4.20–6.39 GHz. All share identical architecture, pinouts, and control interfaces, differing only in the calibrated VCO tuning characteristics.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

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