鈩?/div>
Low Power Dual Frequency Synthesizer for
RF Personal Communications
LMX2330L 2.5 GHz/510 MHz
LMX2331L 2.0 GHz/510 MHz
LMX2332L 1.2 GHz/510 MHz
General Description
The LMX233XL family of monolithic, integrated dual fre-
quency synthesizers, including prescalers, is to be used as a
local oscillator for RF and first IF of a dual conversion
transceiver. It is fabricated using National鈥檚 0.5碌 ABiC V
silicon BiCMOS process.
The LMX233XL contains dual modulus prescalers. A 64/65
or a 128/129 prescaler (32/33 or 64/65 in the 2.5 GHz
LMX2330L) can be selected for the RF synthesizer and a 8/9
or a 16/17 prescaler can be selected for the IF synthesizer.
LMX233XL, which employs a digital phase locked loop tech-
nique, combined with a high quality reference oscillator,
provides the tuning voltages for voltage controlled oscillators
to generate very stable, low noise signals for RF and IF local
oscillators. Serial data is transferred into the LMX233XL via
a three wire interface (Data, Enable, Clock). Supply voltage
can range from 2.7V to 5.5V. The LMX233XL family features
very low current consumption;
LMX2330L 鈥?5.0 mA at 3V, LMX2331L 鈥?4.0 mA at 3V,
LMX2332L 鈥?3.0 mA at 3V.
The LMX233XL are available in a TSSOP 20-pin, CSP
24-pin surface mount plastic package, and thin CSP 20-pin
surface mount plastic package.
Features
n
Ultra low current consumption
n
2.7V to 5.5V operation
n
Selectable synchronous or asynchronous powerdown
mode:
I
CC
= 1 碌A(chǔ) typical at 3V
n
Dual modulus prescaler:
LMX2330L
(RF) 32/33 or 64/65
LMX2331L/32L
(RF) 64/65 or 128/129
LMX2330L/31L/32L (IF) 8/9 or 16/17
n
Selectable charge pump TRI-STATE
廬
mode
n
Selectable charge pump current levels
n
Selectable Fastlock
鈩?/div>
mode
n
Upgrade and compatible to LMX233XA family
Applications
n
Portable Wireless Communications
(PCS/PCN, cordless)
n
Cordless and cellular telephone systems
n
Wireless Local Area Networks (WLANs)
n
Cable TV tuners (CATV)
n
Other wireless communication systems
Functional Block Diagram
01280601
漏 2001 National Semiconductor Corporation
DS012806
www.national.com
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