LMX2581E Series
3.8-GHz wideband frequency synthesizer with integrated VCO
Manufacturer: Texas Instruments
Catalog
3.8-GHz wideband frequency synthesizer with integrated VCO
Key Features
• Output Frequency from 50 to 3800 MHzInput Clock Frequency up to 900 MHzPhase Detector Frequency up to 200 MHzSupports Fractional and Integer Modes–229 dBc/Hz Normalized PLL Phase Noise–120.8 dBc/Hz Normalized PLL 1/f Noise–137 dBc/Hz VCO Phase Noise at 1 MHz offsetfor a 2.5 GHz Carrier100 fs RMS Jitter in Integer ModeProgrammable Fractional ModulatorOrderProgrammable Fractional DenominatorProgrammable Output Power up to 12 dBmProgrammable 32 Level Charge Pump CurrentProgrammable Option to Use an External VCODigital Lock Detect3-Wire Serial Interface and ReadbackSingle Supply Voltage from 3.15 V to 3.45 VSupports Logic Levels down to 1.6 VOutput Frequency from 50 to 3800 MHzInput Clock Frequency up to 900 MHzPhase Detector Frequency up to 200 MHzSupports Fractional and Integer Modes–229 dBc/Hz Normalized PLL Phase Noise–120.8 dBc/Hz Normalized PLL 1/f Noise–137 dBc/Hz VCO Phase Noise at 1 MHz offsetfor a 2.5 GHz Carrier100 fs RMS Jitter in Integer ModeProgrammable Fractional ModulatorOrderProgrammable Fractional DenominatorProgrammable Output Power up to 12 dBmProgrammable 32 Level Charge Pump CurrentProgrammable Option to Use an External VCODigital Lock Detect3-Wire Serial Interface and ReadbackSingle Supply Voltage from 3.15 V to 3.45 VSupports Logic Levels down to 1.6 V
Description
AI
The LMX2581E is a low-noise wideband frequency synthesizer that integrates a delta-sigma fractional N PLL, multiple core VCO, programmable output divider, and two differential output buffers. The VCO frequency range is from 1880 to 3800 MHz and can be sent directly to the output buffers or divided down by even values from 2 to 38. Each buffer is capable of output power from –3 to +12 dBm at 2700 MHz. Integrated low-noise LDOs are used for superior noise immunity and consistent performance.
This synthesizer is a highly programmable device and it enables the user to optimize its performance. In fractional mode, the denominator and the modulator order are programmable and can be configured with dithering as well. The user also has the ability to directly specify a VCO core or entirely bypass the internal VCO. Finally, many convenient features are included such as power down, Fastlock, auto mute, and lock detection. All registers can be programmed through a simple 3-wire interface and a read back feature is also available.
The LMX2581E operates on a single 3.3 V supply and comes in a 32 pin 5.0 mm × 5.0 mmWQFN package.
The LMX2581E is a low-noise wideband frequency synthesizer that integrates a delta-sigma fractional N PLL, multiple core VCO, programmable output divider, and two differential output buffers. The VCO frequency range is from 1880 to 3800 MHz and can be sent directly to the output buffers or divided down by even values from 2 to 38. Each buffer is capable of output power from –3 to +12 dBm at 2700 MHz. Integrated low-noise LDOs are used for superior noise immunity and consistent performance.
This synthesizer is a highly programmable device and it enables the user to optimize its performance. In fractional mode, the denominator and the modulator order are programmable and can be configured with dithering as well. The user also has the ability to directly specify a VCO core or entirely bypass the internal VCO. Finally, many convenient features are included such as power down, Fastlock, auto mute, and lock detection. All registers can be programmed through a simple 3-wire interface and a read back feature is also available.
The LMX2581E operates on a single 3.3 V supply and comes in a 32 pin 5.0 mm × 5.0 mmWQFN package.
