LMX2377U Datasheet, PDF (1/44 Pages) National Semiconductor (TI) – PLLatinum™ Ultra Low Power Dual Frequency Synthesizer for RF Personal Communications

November 2002
LMX2377U
PLLatinum^™ Ultra Low Power Dual Frequency
Synthesizer for RF Personal Communications
2.5 GHz/1.2 GHz
General Description
The LMX2377U device is a high performance frequency
synthesizer with integrated dual modulus prescalers. The
LMX2377U device is designed for use as a local oscillator for
the first and second RF of a dual conversion radio trans-
ceiver.
A 16/17 or a 32/33 prescale ratio can be selected for the
Main synthesizer. An 8/9 or a 16/17 prescale ratio can be
selected for the Aux synthesizer. Using a proprietary digital
phase lock technique, the LMX2377U device generates very
stable, low noise control signals for UHF and VHF voltage
controlled oscillators. Both the Main and Aux synthesizers
include a two-level programmable charge pump. The Main
synthesizer has dedicated Fastlock circuitry.
Serial data is transferred to the devices via a three-wire
interface (Data, LE, Clock). The low voltage logic interface
allows connection to 1.8V devices. Supply voltages from
2.7V to 5.5V are supported. The LMX2377U features ultra
low current consumption, typically 3.5 mA at 3.0V.
The LMX2377U devices are available in 20-Pin TSSOP,
24-Pin CSP, and 20-Pin UTCSP surface mount plastic pack-
ages.
Features
n Ultra Low Current Consumption
n Upgrade and Compatible to the LMX2370
n 2.7V to 5.5V Operation
n 1.8V to 5.0V MICROWIRE Logic Interface
n Selectable Synchronous or Asynchronous Powerdown
Mode:
I_CC-PWDN = 1 µA typical
n Selectable Dual Modulus Prescaler:
Main: 16/17 or 32/33
Aux: 8/9 or 16/17
n Selectable Charge Pump TRI-STATE^® Mode
n Programmable Charge Pump Current Levels
Main and Aux: 0.95 or 3.8 mA
n Selectable Fastlock™ Mode for the Main Synthesizer
n Open Drain Analog Lock Detect Output
n Available in 20-Pin TSSOP, 24-Pin CSP, and 20-Pin
UTCSP
Applications
n Mobile Handsets
(GSM, GPRS, W-CDMA, CDMA, PCS, AMPS, PDC,
DCS)
n Cordless Handsets
(DECT, DCT)
n Wireless Data
n Cable TV Tuners
Thin Shrink Small Outline Package
(MTC20)
Chip Scale Package (SLB24A)
Ultra Thin Chip Scale Package
(SLE20A)
20022680
20022681
20022695
PLLatinum™ is a trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation DS200226
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