Overview
The LTC6948IUFD-2, produced by Analog Devices Inc., is a high-performance, low-noise phase-locked loop (PLL) synthesizer with a fully integrated voltage-controlled oscillator (VCO). This device is designed for applications requiring ultra-low noise and high frequency stability, making it suitable for various RF and microwave systems.
The LTC6948IUFD-2 features a fractional-N synthesizer capable of operating over a wide frequency range from 0.37 GHz to 6.39 GHz. It includes a reference divider, phase-frequency detector (PFD), ultralow noise charge pump, fractional feedback divider, and a VCO output divider. The advanced 4th order Δ∑ modulator in the fractional divider ensures exceptionally low spurious levels and wide loop bandwidths, resulting in extremely low integrated phase noise values.
Key Specifications
| Parameter | Conditions | Min | Typ | Max | Units |
|---|---|---|---|---|---|
| Reference Inputs (REF+, REF–) | fREF Input Frequency | 10 | 425 | MHz | |
| VREF Input Signal Level (Single-Ended, 1µF AC-Coupling Capacitors) | 0.5 | 2 | 2.7 | Vp-p | |
| Input Slew Rate | 20 | V/µs | |||
| Input Duty Cycle | 50 | % | |||
| VCO | fVCO Frequency Range (LTC6948-2) | 3.08 | 4.91 | GHz | |
| KVCO Tuning Sensitivity (LTC6948-2) | 4.7 | 7.0 | %Hz/V | ||
| RF Output (RF+, RF–) | fRF Output Frequency | 0.373 | 6.39 | GHz | |
| Output Divider Range | 1 | 6 | |||
| Output Duty Cycle | 50 | % | |||
| Output Resistance (Single-Ended, Each Output to VRF+) | 100 | 136 | 175 | Ω |
Key Features
- Ultralow Noise: The LTC6948IUFD-2 features exceptionally low phase noise due to its advanced 4th order Δ∑ modulator and wide loop bandwidths.
- Wide Frequency Range: Operates from 0.37 GHz to 6.39 GHz, making it versatile for various RF and microwave applications.
- Integrated VCO: Includes a fully integrated VCO, reference divider, phase-frequency detector (PFD), ultralow noise charge pump, and fractional feedback divider.
- Programmable VCO Output Divider: The output divider range of 1 through 6 extends the output frequency range and provides flexibility in system design.
- Low Spurious Levels: The advanced Δ∑ modulator ensures low spurious levels, enhancing the overall performance of the synthesizer.
Applications
- RF and Microwave Systems: Suitable for various RF and microwave applications requiring high frequency stability and low noise.
- Communications Systems: Ideal for use in communication systems, including base stations, satellite communications, and wireless infrastructure.
- Test and Measurement Equipment: Used in test and measurement equipment where precise frequency generation is critical.
- Radar Systems: Applicable in radar systems that demand high frequency accuracy and low noise.
Q & A
- What is the frequency range of the LTC6948IUFD-2?
The LTC6948IUFD-2 operates over a frequency range from 0.37 GHz to 6.39 GHz.
- What makes the LTC6948IUFD-2 stand out in terms of noise performance?
The device features exceptionally low phase noise due to its advanced 4th order Δ∑ modulator and wide loop bandwidths.
- What components are integrated within the LTC6948IUFD-2?
The device includes a fully integrated VCO, reference divider, phase-frequency detector (PFD), ultralow noise charge pump, and fractional feedback divider.
- What is the range of the VCO output divider?
The VCO output divider range is from 1 to 6.
- What are some typical applications of the LTC6948IUFD-2?
Typical applications include RF and microwave systems, communications systems, test and measurement equipment, and radar systems.
- What is the input frequency range for the reference inputs?
The input frequency range for the reference inputs is from 10 MHz to 425 MHz.
- What is the typical output resistance of the RF output?
The typical output resistance of the RF output is 136 Ω (single-ended, each output to VRF+).
- How does the LTC6948IUFD-2 ensure low spurious levels?
The device ensures low spurious levels through its advanced 4th order Δ∑ modulator.
- What is the tuning sensitivity of the VCO for the LTC6948-2 model?
The tuning sensitivity of the VCO for the LTC6948-2 model is between 4.7%Hz/V and 7.0%Hz/V.
- What is the output duty cycle of the RF output?
The output duty cycle of the RF output is 50%.
