1 Features

1• Multiple Frequency Options Available

– See Device Information Table

– Frequencies From: 553 MHz to 3132 MHz

• PLL Features

– Fractional-N Delta-Sigma Modulator Order

Programmable up to Fourth Order

– FastLock/Cycle Slip Reduction with Timeout

Counter

– Partially Integrated, Adjustable Loop Filter

– Very Low Phase Noise and Spurs

• VCO Features

– Integrated Tank Inductor

– Low Phase Noise

• Other Features

– 2.8-V to 3.2-V Operation

– Low Operating Current

– Low Power-Down Current

– 1.8-V MICROWIRE Support

– 36-Pin 6-mm × 6-mm × 0.8-mm WQFN

Package

2 Applications

• Cellular Base Stations

• Wireless LANs

• Broadband Wireless Access

• Satellite Communications

• Wireless Radios

• Automotive

• CATV Equipment

• Instrumentation and Test Equipment

• RFID Readers

• Data Converter Clocking

3 Description

The LMX2531 is a low-power, high-performance

frequency synthesizer system which includes a fully integrated delta-sigma PLL and VCO with fully

integrated tank circuit. The third and fourth poles are

also integrated and adjustable. Ultra-low noise and

high-precision LDOs are integrated for the PLL and

VCO, which yield higher supply-noise immunity and more consistent performance. When combined with a

high-quality reference oscillator, the LMX2531 device

generates very stable, low-noise local-oscillator

signals for up and down conversion in wireless

communication devices. The LMX2531 device is a monolithic integrated circuit, fabricated in an

advanced BiCMOS process. Several different

versions of this product accommodate different

frequency bands.