LMX2315 LMX2320 LMX2325 PLLatinum Frequency
Synthesizer for RF Personal Communications
LMX2325 2 5 GHz LMX2320 2 0 GHz LMX2315 1 2 GHz
September 1996
LMX2315 LMX2320 LMX2325 PLLatinum
TM
Frequency Synthesizer
for RF Personal Communications
LMX2325 2 5 GHz
LMX2320 2 0 GHz
LMX2315 1 2 GHz
General Description
The LMX2315 2320 2325’s are high performance frequen-
cy synthesizers with integrated prescalers designed for RF
operation up to 2 5 GHz They are fabricated using Nation-
al’s ABiC IV BiCMOS process
A 64 65 or a 128 129 divide ratio can be selected for the
LMX2315 and LMX2320 RF synthesizer at input frequencies
of up to 1 2 GHz and 2 0 GHz while 32 33 and 64 65 divide
ratios are available in the 2 5 GHz LMX2325 Using a propri-
etary digital phase locked loop technique the LMX2315
2320 2325’s linear phase detector characteristics can gen-
erate very stable low noise signals for controlling a local
oscillator
Serial data is transferred into the LMX2320 and the
LMX2325 via a three line MICROWIRE
TM
interface (Data
Enable Clock) Supply voltage can range from 2 7V to 5 5V
The LMX2315 LMX2320 and the LMX2325 feature very low
current consumption typically 6 mA 10 mA and 11 mA re-
spectively
The LMX2315 LMX2320 and the LMX2325 are available in
a TSSOP 20-pin surface mount plastic package
Features
Y
Y
Y
Y
Y
Y
Y
RF operation up to 2 5 GHz
2 7V to 5 5V operation
Low current consumption
Dual modulus prescaler
LMX2325
32 33 or 64 65
LMX2320 LMX2315
64 65 or 128 129
Internal balanced low leakage charge pump
Power down feature for sleep mode
I
CC
e
30
mA
(typ) at V
CC
e
3V
Small-outline plastic surface mount TSSOP 0 173
wide
Applications
Y
Y
Y
Y
Cellular telephone systems
(GSM IS-54 IS-95 (RCR-27)
Portable wireless communications (DECT PHS)
CATV
Other wireless communication systems
Block Diagram
TL W 12339 – 1
TRI-STATE is a registered trademark of National Semiconductor Corporation
MICROWIRE
TM
and PLLatinum
TM
are trademarks of National Semiconductor Corporation
C
1996 National Semiconductor Corporation
TL W 12339
RRD-B30M106 Printed in U S A
http
www national com
NSC [ NATIONAL SEMICONDUCTOR ]
