LMX2522 datasheet(12/18 Pages) NSC

Part #	LMX2522

Description	PLLatinum Frequency Synthesizer System with Integrated VCOs

PDF	18 Pages

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Manufacturer	NSC [National Semiconductor (TI)]

Direct Link	http://www.national.com

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12 / 18 page

Programming Description (Continued)

RF N Counter Setting:

Counter Name

Symbol

Function

Modulus Counter

RF_FN

RF N Divider

N = Prescaler x RF_B + RF_A + (RF_FN / f

OSC)10

Programmable

Counter

RF_B

Swallow Counter

RF_A

Pulse Swallow Function:

f = {Prescaler x RF_B + RF_A + (RF_FN / f

OSC)x10

4}xf

OSC where (RF_A < RF_B)

where

VCO: Output frequency of voltage controlled oscillator (VCO)

Prescaler Values:

Device Type

RF Prescaler

GPS Prescaler

LMX2522

LMX2532

RF_B: Preset divide ratio of binary 4-bit programmable counter (2

≤ RF_B ≤ 15)

RF_A: Preset divide ratio of binary 3-bit swallow counter (0

≤ RF_A ≤ 7 for prescaler of 8 or 0 ≤ RF_A ≤ 5 for prescaler of 6)

RF_FN: Preset numerator of binary 11-bit modulus counter (0

≤ RF_FN < 1920 for f

OSC = 19.20 MHz; 0

≤ RF_FN < 1968 for f

OSC

= 19.68 MHz).

OSC: Reference oscillator frequency

NOTE: For the use of reference frequencies other than those specified, please contact National Semiconductor.

LMX2522 Datasheet(PDF) 12 Page - National Semiconductor (TI)