Features and Benefits
- Low Noise Fractional-N PLL
- No ΔΣ Modulator Spurs
- 18-Bit Fractional Denominator
- 350MHz to 6GHz VCO Input Range
- –226dBc/Hz Normalized In-Band Phase Noise Floor
- –274dBc/Hz Normalized In-Band 1/f Noise
- –157dBc/Hz Wideband Output Phase Noise Floor
- Excellent Integer Boundary Spurious Performance
- Output Divider (1 to 6, 50% Duty Cycle)
- Output Buffer Muting
- Charge Pump Supply from 3.15V to 5.25V
- Charge Pump Current from 1mA to 11.2mA
- Reference Input Frequency Up to 425MHz
- Fast Frequency Switching
The LTC6947 is a high performance, low noise, 6GHz phase-locked loop (PLL), including a reference divider, phase-frequency detector (PFD), ultralow noise charge pump, fractional feedback divider, and VCO output divider.
The fractional divider uses an advanced, 4th order ΔΣ modulator which provides exceptionally low spurious levels. This allows wide loop bandwidths, producing extremely low integrated phase noise values.
The programmable VCO output divider, with a range of 1 through 6, extends the output frequency range. The differential, low-noise output buffer has user-programmable output power ranging from –4.3dBm to +4.5dBm, and may be muted through either a digital input pin or software.
The ultralow noise charge pump contains selectable high and low voltage clamps useful for VCO monitoring, and also may be set to provide a V+/2 bias.
All device settings are controlled through a SPI-compatible serial port.
- Wireless Basestations (LTE, WiMAX, W-CDMA, PCS)
- Broadband Wireless Access
- Microwave Data Links
- Military and Secure Radio
- Test and Measurement
Product Lifecycle Recommended for New Designs
This product has been released to the market. The data sheet contains all final specifications and operating conditions. For new designs, ADI recommends utilization of these products.
Evaluation Kits (2)
Demonstration Circuit 2429A is a PLL/VCO Supply and Reference Frequency Board that features the LT3042, an ultralow noise and ultrahigh PSRR RF linear regulator. When powered from a 6V to 20V lab or wall wart supply, the DC2429A produces four ultralow noise supplies using seven LT3042s. These supplies include a fixed 3.3V/800mA supply (four LT3042's in parallel), a fixed 5V/200mA supply, a fixed 3.3V/200mA supply that powers an onboard 100MHz ultralow jitter crystal oscillator, and an adjustable voltage (2.5V to 15V), 200mA supply ideal for powering external VCOs. The DC2429 ensures PLL/VCO evaluation meets data sheet performance.
Demonstration circuit 1846A features the LTC6947, an Ultralow Noise and Spurious Fractional-N Synthesizer. DC1846A provides 50Ω SMA connectors for the reference frequency (REF+) and the two single-ended RF outputs (RF+ and RF–).
Software & Systems Requirements
Tools & Simulations
Linduino is Analog Devices’ Arduino compatible system for developing and distributing firmware libraries and example code for our integrated circuits. Each Linduino-supported product includes an example main program, defined in the LTSketchbook/Part Number folder and driver code, defined in the LTSketchbook/libraries folder.
Product Selector Card (1)
Solutions Bulletins & Brochures (1)
Technical Articles (1)
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
Sample & Buy
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.