1 Features
1• Output frequency: 12.5 MHz to 6.4 GHz
• Low power consumption: 75 mA at 3.3-V supply
• –106-dBc/Hz Phase noise at 100-kHz offset with
6.4-GHz 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 JESD204B SYSREF with
programmable delay
• 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

2 Applications
• Test and measurement equipment
• Digital 2-way radios
• Low power radio communication systems
• Satellite communication
• Wireless microphones
• Propriety wireless connectivity
• MIMO
• RADAR
• High-speed data converter clocking

3 Description
The LMX2572 is a low-power, high-performance
wideband synthesizer that can generate any
frequency from 12.5 MHz to 6.4 GHz without using an
internal doubler. The PLL delivers excellent
performance while consuming just 75 mA from a
single 3.3-V supply.
For applications like digital mobile radio (DMR) and
wireless microphones, the LMX2572 supports FSK
modulation. Discrete level FSK and pulse-shaping
FSK are supported. Direct digital FSK modulation is
achievable through programming or pins.
The LMX2572 allows users to synchronize the output
of multiple devices and also enables applications that
need deterministic delay between input and output.
The LMX2572 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 LMX2572 also supports
generating or repeating SYSREF (compliant to
JESD204B standard) making it an ideal low-power,
low-noise clock source for clocking high-speed data
converters. Fine delay adjustment is provided in this
configuration to account for delay differences of board
traces.
The LMX2572 integrates LDOs from a single 3.3-V
supply, thus eliminating the need for onboard lownoise
LDOs.