Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

ML12149-5P Fiches technique(PDF) 5 Page - LANSDALE Semiconductor Inc.

No de pièce ML12149-5P
Description  Low Power Voltage Controlled Oscillator Buffer
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  LANSDALE [LANSDALE Semiconductor Inc.]
Site Internet  http://www.lansdale.com
Logo LANSDALE - LANSDALE Semiconductor Inc.

ML12149-5P Fiches technique(HTML) 5 Page - LANSDALE Semiconductor Inc.

  ML12149-5P Datasheet HTML 1Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 2Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 3Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 4Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 5Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 6Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 7Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 8Page - LANSDALE Semiconductor Inc. ML12149-5P Datasheet HTML 9Page - LANSDALE Semiconductor Inc. Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 12 page
background image
www.lansdale.com
Page 5 of 12
LANSDALE Semiconductor, Inc.
ML12149
the capacitance value. To simplify the selection of C1 and Cb, a
table has been constructed based on the intended operating fre-
quency to provide recommended starting points. These may need
to be altered depending on the value of the varactor selected.
The value of the Cb capacitor influences the VCO supply push-
ing. To minimize pushing, the Cb capacitor should be kept small.
Since C1 is in series with the varactor, there is a strong relation-
ship between these two components which influences the VCO
sensitivity. Increasing the value of C1 tends to increase the sensi-
tivity of the VCO.
The parasitic contributions Lp and Cp are related to the
ML12149 as well as parasitics associated with the layout, tank
components, and board material selected. The input capacitance
of the device, bond pad, the wire bond, package/lead capacitance,
wire bond inductance, lead inductance, printed circuit board lay-
out, board dielectric, and proximity to the ground plane all have
an impact on these parasitics. For example, if the ground plane is
located directly below the tank components, a parasitic capacitor
will be formed consisting of the solder pad, metal traces, board
dielectric material, and the ground plane. The test fixture used for
characterizing the device consisted of a two sided copper clad
board with ground plane on the back. Nominal values where
determined by selecting a varactor and characterizing the device
with a number of different tank/frequency combinations and then
performing a curve fit with the data to determine values for Lp
and Cp. The nominal values for the parasitic effects are seen
below:
These values will vary based on the users unique circuit board
configuration.
Basic Guidelines:
1. Select a varactor with high Q and a reasonable
capacitance versus voltage slope for the desired
frequency range.
2. Select the value of Cb and C1 from the table above.
3. Calculate a value of inductance (L) which will result in
achieving the desired center frequency. Note that L
includes both LT and Lp.
4. Adjust the value of C1 to achieve the proper
VCO sensitivity.
5. Re–adjust value of L to center VCO.
6. Prototype VCO design using selected components. It is
important to use similar construction techniques and
materials, board thickness, layout, ground plane
spacing as intended for the final product.
7. Characterize tuning curve over the voltage
operation conditions.
8. Adjust, as necessary, component values – L, C1, and
Cb to compensate for parasitic board effects.
9. Evaluate over temperature and voltage limits.
10. Perform worst case analysis of tank component
variation to insure proper VCO operation over full
temperature and voltage range and make any
adjustments as needed.
Outputs Q and QB are open collector outputs and need a induc-
tor to VCC to provide the voltage bias to the output transistor. In
most applications, DC–blocking capacitors are placed in series
with the output to remove the DC component before interfacing to
other circuitry. These outputs are complementary and should have
identical inductor values for each output. This will minimize
switching noise on the VCC supply caused by the outputs switch-
ing. It is important that both outputs be terminated, even if only
one of the outputs is used in the application.
Referring to Figure 2, the recommended value for L2a and L2b
should be 47 nH and the inductor components resonance should
be at least 300 MHz greater than the maximum operating frequen-
cy. For operation above 1100MHz, it may be necessary to reduce
that inductor value to 33nH. The recommended value for the cou-
pling capacitors C6a, C6b, and C7 is 47 pF. Figure 2 also includes
decoupling capacitors for the supply line as well as decoupling for
the output inductors. Good RF decoupling practices should be
used with a series of capacitors starting with high quality 100pF
chip capacitors close to the device. A typical layout is shown
below in Figure 3.
The output amplitude of the Q and QB can be adjusted using
the CNTL pin. Refering to Figure 1, if the CNTL pin is connected
to ground, additional current will flow through the current source.
When the pin is left open, the nominal current flowing through
the outputs is 4 mA. When the pin is grounded, the current
increases to a nominal value of 10 mA. So if a 50 ohm resistor
was connected between the outputs and VCC, the output ampli-
tude would change from 200 mV pp to 500 mV pp with an addi-
tional current drain for the device of 6 mA. To select a value
between 4 and 10 mA, an external resistor can be added to
ground. The equation below is used to calculate the current.
Figure 4 through Figure 13 illustrate typical performance
achieved with the ML12149. The curves illustrate the tuning
curve, supply pushing characteristics, output power, current drain,
output spectrum, and phase noise performance. In most cases, data
is present for both a 750 MHz and1200 MHz tank design. The
table below illustrates the component values used in the designs.
Frequency
C1
Cb
200 – 500 MHz
47 pF
47 pF
500 – 900 MHz
5.1 pF
15 pF
900 – 1200 MHz
2.7 pF
15 pF
Parasitic Capacitance
Parasitic Inductance
Cp
Lp
4.2 pF
2.2 nH
I=
out(nom)
(200 +
x+
+x
136
Rext)0.8V
200
(136
Rext)
Component
750MHz Tank
1200MHz Tank
Units
R1
5000
5000
C1
5.1
2.7
pF
LT
4.7
1.8
nH
CV
3.7 @ 1.0 V
11 @ 4.0 V
3.7 @ 1.0 V
11 @ 4.0 V
pF
Cb
100*
15
pF
C6, C7
47
33
pF
L2
47
47
nH
NOTE:
* The value of Cb should be reduced to minimize pushing.
Legacy Applications Information
Issue B


Numéro de pièce similaire - ML12149-5P

FabricantNo de pièceFiches techniqueDescription
logo
LANSDALE Semiconductor ...
ML12149-5P LANSDALE-ML12149-5P Datasheet
344Kb / 12P
   Low Power Voltage Controlled Oscillator Buffer
More results

Description similaire - ML12149-5P

FabricantNo de pièceFiches techniqueDescription
logo
LANSDALE Semiconductor ...
ML12149 LANSDALE-ML12149_08 Datasheet
344Kb / 12P
   Low Power Voltage Controlled Oscillator Buffer
logo
Motorola, Inc
MC12147 MOTOROLA-MC12147 Datasheet
391Kb / 12P
   Low Power Voltage Controlled Oscillator Buffer
MC12149 MOTOROLA-MC12149 Datasheet
169Kb / 12P
   LOW POWER VOLTAGE CONTROLLED OSCILLATOR BUFFER
logo
Freescale Semiconductor...
MC12149 FREESCALE-MC12149 Datasheet
362Kb / 12P
   LOW POWER VOLTAGE CONTROLLED OSCILLATOR BUFFER
logo
Motorola, Inc
MC12148 MOTOROLA-MC12148 Datasheet
82Kb / 5P
   LOW POWER VOLTAGE CONTROLLED OSCILLATOR
logo
Z-Communications, Inc
V950ME17-LF ZCOMM-V950ME17-LF Datasheet
85Kb / 2P
   Voltage-Controlled Oscillator Voltage-Controlled Oscillator
ZRO0743B2LF ZCOMM-ZRO0743B2LF Datasheet
85Kb / 2P
   Voltage-Controlled Oscillator Voltage-Controlled Oscillator
V800ME10 ZCOMM-V800ME10_10 Datasheet
82Kb / 2P
   Voltage-Controlled Oscillator Voltage-Controlled Oscillator
logo
SYNERGY MICROWAVE CORPO...
DCYS300600-5 SYNERGY-DCYS300600-5 Datasheet
357Kb / 3P
   VOLTAGE CONTROLLED OSCILLATOR VOLTAGE CONTROLLED OSCILLATOR
DCSO1000-12 SYNERGY-DCSO1000-12 Datasheet
358Kb / 3P
   VOLTAGE CONTROLLED OSCILLATOR
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com