LMX2571 Series

1.34-GHz, low-power, extreme-temperature RF synthesizer with frequency-shift keying (FSK) modulation

Catalog

1.34-GHz, low-power, extreme-temperature RF synthesizer with frequency-shift keying (FSK) modulation

Part	Output	PLL	Type	Mounting Type	Package / Case	Voltage - Supply [Max]	Voltage - Supply [Min]	Number of Circuits	Input	Supplier Device Package	Differential - Input:Output	Ratio - Input:Output [custom]	Operating Temperature [Max]	Operating Temperature [Min]	Frequency - Max [Max]	For Use With/Related Products	Supplied Contents
Texas Instruments LMX2571NJKR	Clock	Yes with Bypass	Frequency Synthesizer (RF)	Surface Mount	36-WFQFN Exposed Pad	3.45 V	3.15 V	1	Clock Crystal	36-WQFN (6x6)	Yes/No	2:2	85 °C	-40 °C	1.4 GHz
Texas Instruments LMX2571EVM			Frequency Synthesizer													LMX2571	Board(s)
Texas Instruments LMX2571NJKT	Clock	Yes with Bypass	Frequency Synthesizer (RF)	Surface Mount	36-WFQFN Exposed Pad	3.45 V	3.15 V	1	Clock Crystal	36-WQFN (6x6)	Yes/No	2:2	85 °C	-40 °C	1.4 GHz

Catalog

1.34-GHz, low-power, extreme-temperature RF synthesizer with frequency-shift keying (FSK) modulation

Key Features

• Any Frequency from 10 MHz to 1344 MHzLow Phase Noise and Spurs–123 dBc/Hz at 12.5 kHz Offset at 480 MHz–145 dBc/Hz at 1 MHz Offset at 480 MHzNormalized PLL Noise Floor of –231 dBc/HzSpurious Better Than –75 dBc/HzNew FastLock to Reduce Lock TimeA Novel Technique to Remove Integer BoundarySpursIntegrated 5-V Charge Pump and Output Dividerfor External VCO Operation2-, 4- and 8-Level or Arbitrary Level Direct DigitalFSK ModulationOne TX/RX Output or Two Fanout OutputsCrystal, XO or Differential Reference Clock InputLow Current Consumption39-mA Typical Synthesizer Mode (InternalVCO)9-mA Typical PLL Mode (External VCO)24-Bit Fractional-N Delta Sigma ModulatorAny Frequency from 10 MHz to 1344 MHzLow Phase Noise and Spurs–123 dBc/Hz at 12.5 kHz Offset at 480 MHz–145 dBc/Hz at 1 MHz Offset at 480 MHzNormalized PLL Noise Floor of –231 dBc/HzSpurious Better Than –75 dBc/HzNew FastLock to Reduce Lock TimeA Novel Technique to Remove Integer BoundarySpursIntegrated 5-V Charge Pump and Output Dividerfor External VCO Operation2-, 4- and 8-Level or Arbitrary Level Direct DigitalFSK ModulationOne TX/RX Output or Two Fanout OutputsCrystal, XO or Differential Reference Clock InputLow Current Consumption39-mA Typical Synthesizer Mode (InternalVCO)9-mA Typical PLL Mode (External VCO)24-Bit Fractional-N Delta Sigma Modulator

Description

The LMX2571 is a low-power, high-performance, wideband PLLatinum RF synthesizer that integrates a delta-sigma fractional N PLL, multiple core voltage-controlled oscillator (VCO), programmable output dividers and two output buffers. The VCO cores work up to 5.376 GHz resulting in continuous output frequency range of 10 MHz to 1344 MHz. This synthesizer can also be used with an external VCO. To that end, a dedicated 5-V charge pump and an output divider are available for this configuration. A unique programmable multiplier is also incorporated to help improve spurs, allowing the system to use every channel even if it falls on an integer boundary. The output has an integrated SPDT switch that can be used as a transmit/receive switch in FDD radio application. Both outputs can also be turned on to provide 2 outputs at the same time. The LMX2571 supports direct digital FSK modulation through programming or pins. Discrete level FSK, pulse shaping FSK, and analog FM modulation are supported. A new FastLock technique can be used allowing the user to step from one frequency to the next in less than 1.5 ms even when an external VCO is used with a narrow band loop filter. The LMX2571 is a low-power, high-performance, wideband PLLatinum RF synthesizer that integrates a delta-sigma fractional N PLL, multiple core voltage-controlled oscillator (VCO), programmable output dividers and two output buffers. The VCO cores work up to 5.376 GHz resulting in continuous output frequency range of 10 MHz to 1344 MHz. This synthesizer can also be used with an external VCO. To that end, a dedicated 5-V charge pump and an output divider are available for this configuration. A unique programmable multiplier is also incorporated to help improve spurs, allowing the system to use every channel even if it falls on an integer boundary. The output has an integrated SPDT switch that can be used as a transmit/receive switch in FDD radio application. Both outputs can also be turned on to provide 2 outputs at the same time. The LMX2571 supports direct digital FSK modulation through programming or pins. Discrete level FSK, pulse shaping FSK, and analog FM modulation are supported. A new FastLock technique can be used allowing the user to step from one frequency to the next in less than 1.5 ms even when an external VCO is used with a narrow band loop filter.