LTC6948IUFD-1#TRPBF

Clock Generators, PLLs, Frequency Synthesizers Overview

The LTC6948IUFD-1#TRPBF is a fractional-N phase-locked loop (PLL) synthesizer with an integrated voltage-controlled oscillator (VCO), manufactured by Analog Devices Inc. It operates in the 2.240 GHz to 3.740 GHz VCO frequency range, providing an output frequency range of 0.373 GHz to 3.740 GHz depending on the programmable output divider setting (1 to 6). The device features a 4th-order delta-sigma modulator for low spurious performance and supports reference input frequencies up to 425 MHz. Key electrical characteristics include a normalized in-band phase noise floor of –226 dBc/Hz and a wideband output phase noise floor of –157 dBc/Hz. It is housed in a 28-lead QFN package.

Clock Generators, PLLs, Frequency Synthesizers Feature Summary

• Integrated VCO with frequency ranges from 0.373 GHz to 6.39 GHz across four variants; this specific part covers 2.240 GHz to 3.740 GHz.
• Advanced 4th-order ΔΣ modulator eliminates discrete spurious tones, enabling wide loop bandwidths and low integrated phase noise.
• Programmable output divider (O_DIV) ranging from 1 to 6 with 50% duty cycle, extending the usable output frequency spectrum.
• Supports reference input frequencies up to 425 MHz and offers fast frequency switching capabilities.

Clock Generators, PLLs, Frequency Synthesizers Applications

• Wireless basestations including LTE, WiMAX, W-CDMA, and PCS systems.
• Microwave data links requiring high-frequency signal generation.
• Military and secure radio communication equipment.
• Test and measurement instrumentation.

Clock Generators, PLLs, Frequency Synthesizers Procurement Notes

Verify that the ordering suffix #TRPBF corresponds to the tape and reel packaging format rather than the tube variant (#PBF). Confirm the specific sub-model designation (-1) matches the required 2.240 GHz to 3.740 GHz VCO frequency range. Ensure the component meets the –40°C to 105°C operating junction temperature specifications for industrial applications.

Clock Generators, PLLs, Frequency Synthesizers Selection Notes

Select the LTC6948IUFD-1 variant specifically when the target VCO frequency range of 2.240 GHz to 3.740 GHz aligns with system requirements. Consider the output divider setting (1–6) to determine the final RF output frequency band. Evaluate the charge pump current settings and loop filter design to optimize phase noise and locking time based on the chosen PFD frequency.

Clock Generators, PLLs, Frequency Synthesizers Part Context

This component belongs to the LTC6948 family of ultralow noise fractional-N synthesizers. The IUFD-1 suffix denotes the specific VCO frequency range option (2.240 GHz to 3.740 GHz) within the broader product line, which also includes options for higher frequency bands. The TRPBF suffix indicates it is supplied in a tape and reel configuration for automated surface-mount assembly.

Clock Generators, PLLs, Frequency Synthesizers Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Other members of the LTC6948 family (LTC6948-2, -3, -4) offer different VCO frequency ranges but share similar architectural features.