Datasheet

DATA
CLK
LE
CE
VccPLL1
VccPLL2
OSCin
OSCin*
RFout
Ftest/LD
LMX2541
Microcontroller
VccCP1
VccCP2
VccRFout
LMK04000
Output
RFoutEN
VregRFout
VccVCO
VccDig
VregVCO
VrefVCO
100 pF
100 :
+3.3V
VccFRAC
VregFRAC
VccDiv
VccOSCin
VccBias
Bypass
4.7:
1 PF
330:
330:
18:
Ferrite
Ferrite
ExtVCOin
To Circuit
10:
1 PF
+3.3V
Ferrite
+3.3V
0.1 PF
4.7:
4.7 PF
+3.3V
0.1 PF
+3.3V
Ferrite
0.1 PF
+3.3V
Ferrite
0.1 PF
+3.3V
Ferrite
0.1 PF
+3.3V
Ferrite
0.1 PF
+3.3V
+3.3 V
+3.3 V
0.1 PF
0.1 PF
Vtune
CPout
C1_LF
R2_LF
C2_LF
FLout
R2pLF
LMX2541SQ2060E, LMX2541SQ2380E
LMX2541SQ2690E, LMX2541SQ3030E
LMX2541SQ3320E, LMX2541SQ3740E
www.ti.com SNOSB31I –JULY 2009–REVISED FEBRUARY 2013
Note that the N divider value has a minimum value, N
Min
, which is implied by the modulator order. N
Min
is 12 for
integer mode and a first order modulator, 13 for a 2nd order modulator,15 for a third order modulator, and 19 for
a fourth order modulator. The maximum phase detector frequency given the electrical specifications, modulator
order, and VCO frequency is shown below.
f
PD
≤ Min( 104 MHz, f
VCO
/ N
Min
) (8)
PLL_NUM[21:0] -- Fractional Numerator
The fractional numerator is formed by the NUM word that is split between two registers and applies in fractional
mode only. The fractional numerator, PLL_NUM must be less than or equal to the fractional denominator,
PLL_DEN.
Fractional
PLL_NUM[21:16] PLL_NUM[15:0]
Numerator
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
...
4194303 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1
APPLICATIONS INFORMATION
Typical Connections
Figure 30. Full Chip Mode, Differential OSCin
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Product Folder Links: LMX2541SQ2060E LMX2541SQ2380E LMX2541SQ2690E LMX2541SQ3030E
LMX2541SQ3320E LMX2541SQ3740E