LMX2512
LMX2512 is Frequency Synthesizer System manufactured by National Semiconductor.
Description
LMX2502 and LMX2512 are highly integrated, high performance, low power frequency synthesizer systems optimized for Korean PCS and Korean Cellular CDMA (1x RTT, 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 munications devices. LMX2502 and LMX2512 include a voltage controlled oscillator (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 Cellular 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 external VCO and loop filter, LMX2502 and LMX2512 make a plete 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 m A 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 k Hz 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 m A 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
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