Overview
The LMX2571NJKR is a low-power, high-performance, wideband PLLatinum RF synthesizer produced by Texas Instruments. This device integrates a delta-sigma fractional N PLL, multiple core voltage-controlled oscillators (VCOs), programmable output dividers, and two output buffers. It operates within a continuous output frequency range of 10 MHz to 1344 MHz, making it versatile for various RF applications. The synthesizer supports both internal and external VCO configurations, with a dedicated 5-V charge pump and output divider for external VCO use. It also features advanced techniques such as FastLock to reduce lock time and a programmable multiplier to improve spurs, allowing the system to utilize every channel even if it falls on an integer boundary.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Package | WQFN (NJK) | - |
| Pins | 36 | - |
| Operating Temperature Range | -40 to 85 | °C |
| Output Frequency Range | 10 MHz to 1344 MHz | - |
| Phase Noise at 12.5 kHz Offset at 480 MHz | -123 dBc/Hz | - |
| Phase Noise at 1 MHz Offset at 480 MHz | -145 dBc/Hz | - |
| Normalized PLL Noise Floor | -231 dBc/Hz | - |
| Spurious Performance | Better than -75 dBc/Hz | - |
| Typical Current Consumption (Synthesizer Mode) | 39 mA | - |
| Typical Current Consumption (PLL Mode) | 9 mA | - |
Key Features
- Any frequency from 10 MHz to 1344 MHz
- Low phase noise and spurs
- New FastLock technique to reduce lock time to less than 1.5 ms
- Programmable multiplier to avoid and reduce integer boundary spurs
- Integrated 5-V charge pump and output divider for external VCO operation
- Direct digital FSK modulation (2-, 4-, and 8-level or arbitrary level)
- Pulse shaping FSK and analog FM modulation support
- One TX/RX output or two fanout outputs
- Crystal, XO, or differential reference clock input
- Low current consumption
- Integrated SPDT switch for transmit/receive switch in FDD radio applications
Applications
- Low Power Radio Communication Systems
- Satcom Modem
- Wireless Microphone
- Proprietary Wireless Connectivity
- Handheld Test and Measurement Equipment
Q & A
- What is the output frequency range of the LMX2571NJKR?
The output frequency range is from 10 MHz to 1344 MHz.
- What types of reference clock inputs are supported by the LMX2571NJKR?
The device supports crystal, XO, or differential reference clock inputs.
- What is the FastLock technique and its benefit?
The FastLock technique reduces the lock time to less than 1.5 ms, even with an external VCO and a narrow band loop filter.
- Does the LMX2571NJKR support FSK modulation?
Yes, it supports direct digital FSK modulation, including 2-, 4-, and 8-level or arbitrary level FSK, as well as pulse shaping FSK and analog FM modulation.
- What is the typical current consumption of the LMX2571NJKR in synthesizer mode?
The typical current consumption in synthesizer mode is 39 mA.
- Can the LMX2571NJKR be used with an external VCO?
Yes, it can be used with an external VCO, with a dedicated 5-V charge pump and output divider available for this configuration.
- What is the operating temperature range of the LMX2571NJKR?
The operating temperature range is from -40°C to 85°C.
- What type of package does the LMX2571NJKR come in?
The device comes in a 36-pin WQFN (NJK) package.
- How does the LMX2571NJKR handle spurious performance?
The device has spurious performance better than -75 dBc/Hz.
- What is the purpose of the integrated SPDT switch in the LMX2571NJKR?
The integrated SPDT switch can be used as a transmit/receive switch in FDD radio applications or as a 1:2 fanout buffer.
