PLLatinum™ Low Power Dual Frequency Synthesizer for
RF Personal Communications
1.1 GHz/1.1 GHz
2.0 GHz/1.1 GHz
The LMX2335L and LMX2336L are monolithic, integrated
dual frequency synthesizers, including two high frequency
prescalers, and are designed for applications requiring two
RF phase-lock loops. They are fabricated using National’s
0.5µ ABiC V silicon BiCMOS process.
The LMX2335L/36L contains two dual modulus prescalers. A
64/65 or a 128/129 prescaler can be selected for each RF
synthesizer. A second reference divider chain is included in
the IC for improved system noise. The LMX2335L/36L com-
bined with a high quality reference oscillator, two loop filters,
and two external voltage controlled oscillators generates
very stable low noise RF local oscillator signals.
Serial data is transferred into the LMX2335L/36L via a three
wire interface (Data, Enable, Clock). Supply voltage can
range from 2.7V to 5.5V. The LMX2335L/36L feature very
low current consumption; LMX2335L 4.0 mA at 5V,
LMX2336L 5.5 mA at 5V. The LMX2335L is available in SO,
TSSOP and CSP 16-pin surface mount plastic packages.
The LMX2336L is available in a TSSOP 20-pin and CSP
24-pin surface mount plastic package.
n Ultra low current consumption
n 2.7V to 5.5V operation
n Selectable synchronous and asynchronous powerdown
ICC = 1 µA (typ)
n Dual modulus prescaler: 64/65 or 128/129
n Selectable charge pump TRI-STATE® mode
n Selectable charge pump current levels
n Selectable Fastlock™ mode
n Upgrade and compatible to LMX2335/36
n Small-outline, plastic, surface mount TSSOP package
n LMX2336 available in CSP package
n Cellular telephone systems (AMPS, ETACS, RCR-27)
n Cordless telephone systems
(DECT, ISM , PHS, CT-1+)
n Personal Communication Systems
n Dual Mode PCS phones
n Cable TV Tuners (CATV)
n Other wireless communication systems
Functional Block Diagram
TRI-STATE® is a registered trademark of National Semiconductor Corporation.
Fastlock™, MICROWIRE™ and PLLatinum™ are trademarks of National Semiconductor Corporation.
© 1999 National Semiconductor Corporation DS012807