LMX2305TM National Semiconductor, LMX2305TM Datasheet

no-image

LMX2305TM

Manufacturer Part Number
LMX2305TM
Description
IC FREQ SYNTHESIZER 20-TSSOP
Manufacturer
National Semiconductor
Series
PLLatinum™r
Type
PLL Frequency Synthesizerr
Datasheet

Specifications of LMX2305TM

Pll
Yes
Input
Clock
Output
Clock
Number Of Circuits
1
Ratio - Input:output
1:1
Differential - Input:output
Yes/No
Frequency - Max
550MHz
Divider/multiplier
Yes/No
Voltage - Supply
2.65 V ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
20-TSSOP
Frequency-max
550MHz
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Other names
*LMX2305TM

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
LMX2305TMD
Manufacturer:
NS/国半
Quantity:
20 000
C 1996 National Semiconductor Corporation
LMX2305
PLLatinum
for RF Personal Communications
General Description
The LMX2305 is a high performance frequency synthesizer
with an integrated prescaler designed for RF operation up to
550 MHz It is fabricated using National’s ABiC IV BiCMOS
process
The LMX2305 contains a dual modulus prescaler which can
select either a 64 65 or a 128 129 divide ratio at input fre-
quencies of up to 550 MHz LMX2305 which employs the
digital phase lock loop technique combined with a high
quality reference oscillator and a loop filter provides the
tuning voltage for the voltage controlled oscillator to gener-
ate a very stable low noise local oscillator signal
Serial data is transferred into the LMX2305 via a three line
MICROWIRE
age can range from 2 65V to 5 5V The LMX2305 features
very low current consumption typically 4 0 mA at 2 75V
The LMX2305 is available in a TSSOP 20-pin surface mount
plastic package
Block Diagram
TRI-STATE is a registered trademark of National Semiconductor Corporation
MICROWIRE
TM
and PLLatinum
TM
interface (Data Enable Clock) Supply volt-
TM
are trademarks of National Semiconductor Corporation
TM
550 MHz Frequency Synthesizer
TL W 12459
Features
Y
Y
Y
Y
Y
Y
Applications
Y
Y
Y
Y
Y
RF operation up to 550 MHz
2 65V to 5 5V operation
Low current consumption
I
Dual modulus prescaler 64 65 or 128 129
Internal balanced low leakage charge pump
Small-outline plastic surface mount TSSOP
0 173 wide package
Analog Cellular telephone systems
(AMPS ETACS NMT)
Portable wireless communications
(PCS PCN cordless)
Wireless local area networks (WLANs)
Other wireless communication systems
Pagers
CC
e
RRD-B30M126 Printed in U S A
4 0 mA (typ) at V
CC
e
2 75V
PRELIMINARY
http
www national com
August 1996
TL W 12459 – 1

Related parts for LMX2305TM

LMX2305TM Summary of contents

Page 1

... The LMX2305 features very low current consumption typically 75V The LMX2305 is available in a TSSOP 20-pin surface mount plastic package Block Diagram TRI-STATE is a registered trademark of National Semiconductor Corporation MICROWIRE TM and PLLatinum TM are trademarks of National Semiconductor Corporation ...

Page 2

... Output for external charge pump connect http www national com LMX2305 20-Lead (0 173 Wide) Thin Shrink Small Outline Package (TM) Order Number LMX2305TM or LMX2305TMX See NS Package Number MTC20 Description 2 input threshold and can be driven from open drain N-channel transistor and requires a pull-up ...

Page 3

Functional Block Diagram Note 1 The power down function is gated by the charge pump to prevent any unwanted frequency jumps Once the power down pin is brought low the part will go into power down mode when the charge ...

Page 4

... Absolute Maximum Ratings If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Power Supply Voltage Voltage on Any Pin with GND Storage Temperature Range ( Lead Temperature (T ) (solder 4 sec ) L Electrical Characteristics Symbol Parameter I Power Supply Current ...

Page 5

Electrical Characteristics Symbol Parameter I Charge Pump Output Current D o -source -sink I Charge Pump TRI-STATE Current D o -Tri V High-Level Output Voltage OH V Low-Level Output Voltage OL V High-Level Output Voltage (OSC OH ...

Page 6

Functional Description The simplified block diagram below shows the 19-bit data register the 14-bit R Counter and the R15 Latch and the 18-bit N Counter (intermediate latches are not shown) The data stream is clocked (on the rising edge) into ...

Page 7

Functional Description (Continued) PROGRAMMABLE DIVIDER (N COUNTER) The N counter consists of the 7-bit swallow counter (A counter) and the 11-bit programmable counter (B counter) If the Control Bit (last bit shifted into the Data Register) is LOW data is ...

Page 8

Functional Description (Continued) SERIAL DATA INPUT TIMING Notes Parenthesis data indicates programmable reference divider data Data shifted into register on clock rising edge Data is shifted in MSB first Test Conditions The Serial Data Input Timing is tested using a ...

Page 9

Analog Switch The analog switch is useful for radio systems that utilize a frequency scanning mode and a narrow band mode The purpose of the analog switch is to decrease the loop filter time constant allowing the VCO to adjust ...

Page 10

Typical Application Example Operational Notes VCO is assumed AC coupled R increases impedance so that VCO output power is provided to the load rather than the PLL Typical values are 10 IN level f RF impedance ranges from 40 to ...

Page 11

Application Information LOOP FILTER DESIGN A block diagram of the basic phase locked loop is shown FIGURE 1 Basic Charge Pump Phase Locked Loop An example of a passive loop filter configuration including the transfer function of the loop filter ...

Page 12

Application Information (Continued) Therefore if we specify the loop bandwidth phase margin Equations 1 through 6 allow us to calcu- p late the two time constants T1 and T2 as shown in equa- tions 7 and 8 A common rule ...

Page 13

Application Information (Continued) EXTERNAL CHARGE PUMP The LMX PLLatinum series of frequency synthesizers are equipped with an internal balanced charge pump as well as outputs for driving an external charge pump Although the superior performance of NSC’s on board charge ...

Page 14

... Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead (0 173 Wide) Thin Shrink Small Outline Package (TM) For Tape and Reel Order Number LMX2305TMX (2500 Units per Reel) LIFE SUPPORT POLICY NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT ...

Related keywords