LMX2502 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – PLLatinum™ Frequency Synthesizer System with Integrated VCO

June 2003
LMX2502/LMX2512
PLLatinum^™ Frequency Synthesizer System with
Integrated VCO
General Description
LMX2502 and LMX2512 are highly integrated, high perfor-
mance, low power frequency synthesizer systems optimized
for Korean PCS and Korean Cellular CDMA (1xRTT, IS-95)
mobile handsets. Using a proprietary digital phase locked
loop technique, LMX2502 and LMX2512 generate very
stable, low noise local oscillator signals for up and down
conversion in wireless communications devices.
LMX2502 and LMX2512 include a voltage controlled oscil-
lator (VCO), a loop filter, and a fractional-N RF PLL based on
a delta sigma modulator. In concert these blocks form a
closed loop RF synthesizer system. LMX2502 supports the
Korean PCS band and LMX2512 supports the Korean Cel-
lular band.
LMX2502 and LMX2512 include an Integer-N IF PLL also.
For more flexible loop filter designs, the IF PLL includes a
4-level programmable charge pump. Together with an exter-
nal VCO and loop filter, LMX2502 and LMX2512 make a
complete closed loop IF synthesizer system.
Serial data is transferred to the device via a three-wire
MICROWIRE interface (DATA, LE, CLK).
Operating supply voltage ranges from 2.7 V to 3.3 V.
LMX2502 and LMX2512 feature low current consumption:
17 mA at 2.8 V.
LMX2502 and LMX2512 are available in a 28-pin leadless
leadframe package (LLP).
Features
n Small Size
5.0 mm X 5.0 mm X 0.75 mm 28-Pin LLP Package
n RF Synthesizer System
Integrated RF VCO
Integrated Loop Filter
Low Spurious, Low Phase Noise Fractional-N RF PLL
Based on 11-Bit Delta Sigma Modulator
10 kHz Frequency Resolution
n IF Synthesizer System
Integer-N IF PLL
Programmable Charge Pump Current Levels
Programmable Frequency
n Supports Various Reference Frequencies
19.20/19.68 MHz
n Fast Lock Time: 500 µs
n Low Current Consumption
17 mA at 2.8 V
n 2.7 V to 3.3 V Operation
n Digital Filtered Lock Detect Output
n Hardware and Software Power Down Control
Applications
n Korean PCS CDMA Systems
n Korean Cellular CDMA Systems
Functional Block Diagram
PLLatinum™ is a trademark of National Semiconductor Corporation.
© 2003 National Semiconductor Corporation DS200680
20068001
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