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Features
Pin compatible/functional equivalent to the LMX2350
Enhanced Low Noise Fractional Engine
2.7V to 5.5V operation
Low current consumption LMX2354: ICC = 7 mA typical at 3V
Programmable or logical power down mode: ICC = 5 µA typical at 3V
Modulo 15 or 16 fractional RF N divider supports ratios of 1, 2, 3, 4, 5, 8, 15, or 16
Programmable charge pump current levels RF 100 µA to 1.6 mA in 100 µA steps IF 100 µA or 800 µA
Digital filtered lock detect
Available in 24-pin TSSOP and 24-pin CSP
Description The LMX2354 is part of a family of monolithic integrated fractional N/Integer N frequency synthesizers designed to be used in a local oscillator subsystem for a radio transceiver. It is fabricated using National's 0.5 µ ABiC V silicon BiCMOS process. The LMX2354 contains quadruple modulus prescalers along with modulo 15 or 16 fractional compensation circuitry in the RF divider. The LMX2354 provides a continuous divide ratio of 80 to 32767 in 16/17/20/21 (1.2 GHz-2.5 GHz) fractional mode and 40 to 16383 in 8/9/12/13 (550 MHz-1.2 GHz) fractional mode. The IF circuitry for the LMX2354 contains an 8/9 prescaler, and is fully programmable. Using a fractional N phase locked loop technique, the LMX2354 can generate very stable low noise control signals for UHF and VHF voltage controlled oscillators (VCOs).
For the RF PLL, a highly flexible 16 level programmable charge pump supplies output current magnitudes from 100 µA to 1.6 mA. Two uncommitted CMOS outputs can be used to provide external control signals, or configured to FastLock mode. Serial data is transferred into the LMX2354 via a three wire interface (Data, LE, Clock). Supply voltage can range from 2.7V to 5.5V. The LMX2354 family features very low current consumption; typically LMX2354 (2.5 GHz) - 7.0 mA. The LMX2354 are available in a 24-pin TSSOP surface mount plastic package and 24-pin CSP.
Applications
Portable wireless communications (PCS/PCN, cordless)
Dual mode cellular telephone systems
Zero blind slot TDMA systems
Spread spectrum communication systems (CDMA)
Cable TV Tuners (CATV)
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Also Recommended
| LMX2470 | Delta-Sigma For Lowest Phase Noise, Low Spurs, & Fastest Lock Time |
| LMX2485 | Delta-Sigma For Lowest Phase Noise, Lowest Spurs, & Fastest Lock Time |
| LMX2364▲ | Lower Phase Noise & Lower Spurs |
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