LMX2491 Series

6.4-GHz low noise fractional-N PLL with ramp/chirp generation

Catalog

6.4-GHz low noise fractional-N PLL with ramp/chirp generation

Part	Ratio - Input:Output	Mounting Type	Output	Frequency - Max [Max]	Type	Package / Case	PLL	Voltage - Supply [Max]	Voltage - Supply [Min]	Input	Differential - Input:Output	Operating Temperature [Max]	Operating Temperature [Min]	Number of Circuits	Supplier Device Package
Texas Instruments LMX2491RTWT	2:1	Surface Mount	Clock	6.4 GHz	Frequency Synthesizer (RF)	24-WFQFN Exposed Pad		3.45 V	3.15 V	Clock		125 °C	-40 °C	1	24-WQFN (4x5)
Texas Instruments LMX2491RTWR	2:1	Surface Mount	Clock	6.4 GHz	Frequency Synthesizer (RF)	24-WFQFN Exposed Pad		3.45 V	3.15 V	Clock		125 °C	-40 °C	1	24-WQFN (4x5)

Catalog

6.4-GHz low noise fractional-N PLL with ramp/chirp generation

Key Features

• –227-dBc/Hz Normalized PLL Noise500-MHz to 6.4-GHz Wideband PLL3.15-V to 5.25-V Charge Pump PLL SupplyVersatile Ramp / Chirp Generation200-MHz Maximum Phase Detector FrequencyFSK / PSK Modulation PinDigital Lock DetectSingle 3.3-V Supply Capability–227-dBc/Hz Normalized PLL Noise500-MHz to 6.4-GHz Wideband PLL3.15-V to 5.25-V Charge Pump PLL SupplyVersatile Ramp / Chirp Generation200-MHz Maximum Phase Detector FrequencyFSK / PSK Modulation PinDigital Lock DetectSingle 3.3-V Supply Capability

Description

The LMX2491 device is a low-noise, 6.4-GHz wideband delta-sigma fractional N PLL with ramp and chirp generation. It consists of a phase frequency detector, programmable charge pump, and high frequency input for the external VCO. The LMX2491 supports a broad and flexible class of ramping capabilities, including FSK, PSK, and configurable piecewise linear FM modulation profiles of up to 8 segments. It supports fine PLL resolution and fast ramp with up to a 200-MHz phase detector rate. The LMX2491 allows any of its registers to be read back. The LMX2491 can operate with a single 3.3-V supply. Moreover, supporting up to 5.25-V charge pump can eliminate the need of external amplifier, leading to a simpler solution with improved phase noise performance. The LMX2491 device is a low-noise, 6.4-GHz wideband delta-sigma fractional N PLL with ramp and chirp generation. It consists of a phase frequency detector, programmable charge pump, and high frequency input for the external VCO. The LMX2491 supports a broad and flexible class of ramping capabilities, including FSK, PSK, and configurable piecewise linear FM modulation profiles of up to 8 segments. It supports fine PLL resolution and fast ramp with up to a 200-MHz phase detector rate. The LMX2491 allows any of its registers to be read back. The LMX2491 can operate with a single 3.3-V supply. Moreover, supporting up to 5.25-V charge pump can eliminate the need of external amplifier, leading to a simpler solution with improved phase noise performance.