LMX2531LQ1500E Datasheet, PDF (1/23 Pages) National Semiconductor (TI) – High Performance Frequency Synthesizer System with Integrated VCO

October 2006
LMX2531LQ1500E
High Performance Frequency Synthesizer System with
Integrated VCO
General Description
The LMX2531LQ1500E is a low power, high performance
frequency synthesizer system which includes a fully inte-
grated delta-sigma PLL and VCO with fully integrated tank
circuit. The third and fourth poles are also integrated and
also adjustable. Also included are integrated ultra-low noise
and high precision LDOs for the PLL and VCO which give
higher supply noise immunity and also more consistent per-
formance. When combined with a high quality reference
oscillator, the LMX2531LQ1500E generates very stable, low
noise local oscillator signals for up and down conversion in
wireless communication devices. The LMX2531LQ1500E is
a monolithic integrated circuit, fabricated in an advanced
BiCMOS process. There are several different versions of this
product in order to accomdate different frequency bands.
Device programming is facilitated using a three-wire
MICROWIRE Interface that can operate down to 1.8 volts.
Supply voltage range is 2.8 to 3.2 Volts. The
LMX2531LQ1500E is available in a 36 pin 6x6x0.8 mm
Lead-Free Leadless Leadframe Package (LLP).
Features
PLL Features
— Fractional-N Delta Sigma Modulator Order
programmable up to 4th 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
— 1499 - 1510 MHz Output Frequency
— 749.5 - 755 MHz Output Frequency (Divide by 2
Mode)
Other Features
— 2.8 V to 3.2 V Operation
— Low Power-Down Current
— 1.8V MICROWIRE Support
— Package: 36 Lead LLP
Target Applications
n Data Converting Clocking
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