Datasheet

LMX2541SQ2060E, LMX2541SQ2380E
LMX2541SQ2690E, LMX2541SQ3030E
LMX2541SQ3320E, LMX2541SQ3740E
SNOSB31I –JULY 2009–REVISED FEBRUARY 2013 www.ti.com
Electrical Characteristics (continued)
(3.15 V ≤ V
CC
≤ 3.45 V, -40°C ≤ T
A
≤ 85 °C; except as specified. Typical values are at Vcc = 3.3 V, 25 C.)
Symbol Parameter Conditions Min Typ Max Units
13 -
2060E
23
16 -
2380E
The lower number in the range
30
applies when the VCO is at its
17 -
lowest frequency and the higher
2690E
32
number applies when the VCO
K
Vtune
Fine Tuning Sensitivity MHz/V
is at its highest frequency. A
20 -
3030E
linear approximation can be
37
used for frequencies between
21 -
these two cases.
3320E
37
24 -
3740E
42
Default Power Mode VCO_DIV = 2 -20
Second Harmonic
HS
RFout
(8)
dBc
(7)
VCO_DIV = 3 -20
50 Ω Load
Default Power Mode VCO_DIV = 2 3
Duty Cycle Error
DE
RFout
(8)
%
(7)
VCO_DIV = 3 3
50 Ω Load
PSH
VCO
VCO Frequency Pushing C
VregVCO
= 4.7 µF, Open Loop 600 kHz/V
VCO_DIV = 1 ±800
VSWR 1.7 to 1
PUL
VCO
VCO Frequency Pulling kHz
(6 dB Pad)
VCO_DIV > 1 ±60
2060E 1.6
Integration Bandwidth
2380E 1.8
= 100 Hz to 20 MHz
Middle VCO Frequency
2690E 2.1
σ
Φ
RMS Phase Error 100 MHz Wenzel Crystal mRad
3030E 2.1
Reference
Integer Mode
3320E 2.3
Optimized Loop Bandwidth
3740E 2.6
VCO Phase Noise
(9)
10 kHz Offset -89.7
100 kHz Offset -113.7
f
RFout
=
Min VCO 1 MHz Offset -134.9
Frequency
10 MHz Offset -155.4
20 MHz Offset -160.3
Phase Noise
L(f)
Fout
dBc/Hz
2060E
10 kHz Offset -86.5
100 kHz Offset -111.4
f
RFout
=
Max VCO 1 MHz Offset -132.8
Frequency
10 MHz Offset -153.4
20 MHz Offset -158.5
(7) The duty cycle error (DE) and second harmonic (HS) are theoretically related by the equation HS = 10·log| 2π·DE | - 6 dB. A square
wave with 3% duty cycle theoretically has a second harmonic of -20 dBc.
(8) The LMX2541 RFout power level is programmable with the program words of VCOGAIN, OUTTERM, and DIVGAIN. Changing these
words can change the output power of the VCO as well as the current consumption of the output buffer. For the purpose of consistency
in electrical specifications, "Default Power Mode" is defined to be the settings of VCOGAIN = OUTTERM = DIVGAIN = 12.
(9) The VCO phase noise is measured assuming that the loop bandwidth is sufficiently narrow that the VCO noise dominates. The phase
noise is measured with AC_TEMP_COMP = 5 and the device is reloaded at each test frequency. The typical performance
characteristics section shows how the VCO phase noise varies over temperature and frequency.
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Product Folder Links: LMX2541SQ2060E LMX2541SQ2380E LMX2541SQ2690E LMX2541SQ3030E
LMX2541SQ3320E LMX2541SQ3740E