LMX2306/LMX2316/LMX2326
PLLatinum™ Low Power Frequency Synthesizer for RF
Personal Communications
LMX2306
550 MHz
LMX2316
1.2 GHz
LMX2326
2.8 GHz
General Description
Features
The LMX2306/16/26 are monolithic, integrated frequency
synthesizers with prescalers that are designed to be used to
generate a very stable low noise signal for controlling the
local oscillator of an RF transceiver. They are fabricated
using National’s ABiC V silicon BiCMOS 0.5µ process.
The LMX2306 contains a 8/9 dual modulus prescaler while
the LMX2316 and the LMX2326 have a 32/33 dual modulus
prescaler. The LMX2306/16/26 employ a digital phase
locked loop technique. When combined with a high quality
reference oscillator and loop filter, the LMX2306/16/26 provide the feedback tuning voltage for a voltage controlled
oscillator to generate a low phase noise local oscillator signal. Serial data is transferred into the LMX2306/16/26 via a
three wire interface (Data, Enable, Clock). Supply voltage
can range from 2.3V to 5.5V. The LMX2306/16/26 feature
ultra low current consumption; LMX2306 - 1.7 mA at 3V,
LMX2316 - 2.5 mA at 3V, and LMX2326 - 4.7 mA at 3V.
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The LMX2306/16/26 synthesizers are available in a 16-pin
TSSOP surface mount plastic package.
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2.3V to 5.5V operation
Ultra low current consumption
2.5V VCC JEDEC standard compatible
Programmable or logical power down mode:
— ICC = 1 µA typical at 3V
Dual modulus prescaler:
— LMX2306
8/9
— LMX2316/26
32/33
Selectable charge pump TRI-STATE ® mode
Selectable FastLock™ mode with timeout counter
MICROWIRE™ Interface
Digital Lock Detect
Applications
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Portable wireless communications (PCS/PCN, cordless)
Wireless Local Area Networks (WLANs)
Cable TV tuners (CATV)
Pagers
Other wireless communication systems
Functional Block Diagram
10012701
TRI-STATE ® is a registered trademark of National Semiconductor Corporation.
FastLock™, PLLatinum™ and MICROWIRE™ are trademarks of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation
DS100127
www.national.com
LMX2306/LMX2316/LMX2326 PLLatinum Low Power Frequency Synthesizer for RF Personal
Communications
March 2004
