January 10, 2012 – Linear Technology Korea (CEO Hong Sa-gwak) announced the development of a high-performance 6GHz Integer-N frequency synthesizer (product name: LTC6945). This device is characterized by delivering exceptional normalized closed-loop in-band phase noise of -226dBc/Hz, normalized in-band 1/f noise of -274dBc/Hz, wideband phase noise floor of -157dBc/Hz, and industry-leading spurious output of -102dBc. Thanks to these outstanding performance characteristics, it is possible to achieve closed-loop phase noise of -100dBc/Hz at 1kHz offset in typical 900MHz applications. The LTC6945 is designed to operate with external low-noise VCOs up to 6GHz maximum. Furthermore, this device is equipped with an on-chip programmable output divider (programmable from 1 to 6) that enables extension of frequency coverage down to approximately 350MHz.
The LTC6945 consists of a low-noise reference buffer, reference divider, PFD (phase-frequency detector) with phase-locked indicator function, programmable ultra-low noise charge pump, and integer feedback divider for ultra-low noise PLL operation. The on-chip SPI-compatible bidirectional serial port enables frequency tuning and control, register read back, and loop status information provision.
The low phase noise and spurious characteristics of the LTC6945 can enhance the performance of all types of RF and wireless equipment, including multi-band base stations supporting LTE, W-CDMA, UMTS, CDMA, multi-carrier GSM, and WiMAX standards. This product can also be utilized in point-to-point broadband wireless access, military, aviation, and high-performance instrumentation applications due to its wide frequency range.
Connection with the LTC6945 evaluation board and PLLWizard™ comprehensive PC-based design tool software are provided to enable easier interchangeable control. Designers can use the PLLWizard software to perform simulation and optimization tasks, and bidirectionally verify their designs in actual demonstration circuits. The PLLWizard design tool can be downloaded free of charge from www.linear.com/PLLWizard.
The LTC6945 is designed to operate over the full case temperature range of -40°C ~ 105°C. The LTC6945 is currently available in a 4mm x 5mm, 28-pin plastic QFN package, with a price of $4.95 per unit based on quantities of 1,000 pieces. For detailed information, refer to www.linear.com/product/LTC6945.

Photo Description: Ultra-Low Noise and Spurious 6GHz Frequency Synthesizer

Product Features: LTC6945

• Excellent in-band phase noise: -226dBc/Hz (closed-loop, normalized)
• Industry-leading in-band 1/f noise performance: -274dBc/Hz (closed-loop, normalized)
• -157dBc/Hz wideband output phase noise floor
• Very low spurious output: -102dBc
• Charge pump programmable up to maximum 11.2mA output current
• PLLWizard™ design tool software support
• On-chip output divider with wide tuning frequency range capable down to approximately 350MHz