lmx2532 National Semiconductor Corporation, lmx2532 Datasheet - Page 12

• Manufacturer Part Number: lmx2532
• Description: Pllatinum Frequency Synthesizer System With Integrated Vcos
• Manufacturer: National Semiconductor Corporation

www.national.com
Programming Description
RF N Counter Setting:
Pulse Swallow Function:
f = {Prescaler x RF_B + RF_A + (RF_FN / f
where
f
Prescaler Values:
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
= 19.68 MHz).
f
NOTE: For the use of reference frequencies other than those specified, please contact National Semiconductor.
VCO
OSC
: Output frequency of voltage controlled oscillator (VCO)
: Reference oscillator frequency
Counter Name
Modulus Counter
Programmable
Counter
Swallow Counter
Device Type
LMX2522
LMX2532
Symbol
RF_FN
RF_B
RF_A
OSC
(Continued)
) x 10
4
} x f
RF Prescaler
OSC
8
6
12
where (RF_A
Function
RF N Divider
N = Prescaler x RF_B + RF_A + (RF_FN / f
<
1920 for f
<
RF_B)
OSC
= 19.20 MHz; 0 ≤ RF_FN
GPS Prescaler
6
8
OSC
<
) 10
1968 for f
4
OSC