LMX2572LP 2-GHz Low Power Wideband RF Synthesizer With FSK Modulation | TI.com


2-GHz Low Power Wideband RF Synthesizer With FSK Modulation



The LMX2572LP is a low-power, high-performance wideband synthesizer that can generate one frequency from 12.5 MHz to 2 GHz without the use of an internal doubler. The PLL delivers excellent performance while consuming just 70 mA from a single 3.3-V supply.

For applications like digital mobile radio (DMR) and wireless microphones, the LMX2572LP supports FSK modulation. Discrete level FSK and pulse-shaping FSK are supported. Direct digital FSK modulation is achievable through programming or pins.

The LMX2572LP allows users to synchronize the output of multiple devices and also enables applications that need deterministic delay between input and output. The LMX2572LP provides an option to adjust the phase with fine granularity to account for delay mismatch on the board or within devices. A frequency ramp generator can synthesize up to two segments of ramp in an automatic ramp generation option or a manual option for maximum flexibility. The fast calibration algorithm allows the user to change frequencies faster than 20 µs.

The LMX2572LP integrates LDOs from a single 3.3-V supply, thus eliminating the need for onboard low-noise LDOs.


  • Output Frequency: 12.5 MHz to 2 GHz
  • Low Power Consumption: 70 mA at 3.3-V Supply
  • –124-dBc/Hz Phase Noise at 100-kHz Offset With 800-MHz Carrier
  • PLL Figure of Merit: –232 dBc/Hz
  • PLL Normalized 1/f Noise: –123.5 dBc/Hz
  • 32-Bit Fractional-N Divider
  • Remove Integer Boundary Spurs With Programmable Input Multiplier
  • Synchronization of Output Phase Across Multiple Devices
  • Support for Ramp and Chirp Functions
  • Support for FSK Direct Digital Modulation
  • Two Programmable Output Power Level Differential Outputs
  • Fast VCO Calibration Speed: < 20 µs
  • Single 3-V to 3.5-V Power Supply

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Parametrics Compare all products in RF PLLs & synthesizers

Output frequency (Min) (MHz)
Output frequency (Max) (MHz)
Normalized PLL phase noise (dBc/Hz)
1/f noise (10-kHz offset at 1-GHz carrier) (dBc/Hz)
Current consumption (mA)
Integrated VCO
LMX2572LP LMX2571 LMX2572 LMX2582 LMX2592 LMX2594
  10     28     20     20     10    
  1344     6400     5500     9800     15000    
-232     -231     -232     -231     -231     -236    
-123.5     -124     -124     -126     -126     -129    
70     39     75     250     250     340    
3.3     3.15 to 5     3.3     3.15 to 3.45     3.15 to 3.45     3.15 to 3.45    
Yes     Yes     Yes     Yes     Yes     Yes