Datenblatt-Suchmaschine für elektronische Bauteile
  German  ▼
ALLDATASHEETDE.COM

X  

LM2465 Datenblatt(PDF) 6 Page - National Semiconductor (TI)

[Old version datasheet] Texas Instruments acquired National semiconductor.
Teilenummer LM2465
Bauteilbeschribung  Monolithic Triple 5.5 ns High Gain CRT Driver
Download  12 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Hersteller  NSC [National Semiconductor (TI)]
Direct Link  http://www.national.com
Logo NSC - National Semiconductor (TI)

LM2465 Datenblatt(HTML) 6 Page - National Semiconductor (TI)

Back Button LM2465 Datasheet HTML 2Page - National Semiconductor (TI) LM2465 Datasheet HTML 3Page - National Semiconductor (TI) LM2465 Datasheet HTML 4Page - National Semiconductor (TI) LM2465 Datasheet HTML 5Page - National Semiconductor (TI) LM2465 Datasheet HTML 6Page - National Semiconductor (TI) LM2465 Datasheet HTML 7Page - National Semiconductor (TI) LM2465 Datasheet HTML 8Page - National Semiconductor (TI) LM2465 Datasheet HTML 9Page - National Semiconductor (TI) LM2465 Datasheet HTML 10Page - National Semiconductor (TI) Next Button
Zoom Inzoom in Zoom Outzoom out
 6 / 12 page
background image
Application Hints (Continued)
OPTIMIZING TRANSIENT RESPONSE
Referring to
Figure 9, there are three components (R1, R2
and L1) that can be adjusted to optimize the transient
response of the application circuit. Increasing the values of
R1 and R2 will slow the circuit down while decreasing
overshoot. Increasing the value of L1 will speed up the circuit
as well as increase overshoot. It is very important to use
inductors
with
very
high
self-resonant
frequencies,
preferably above 300MHz. Ferrite core inductors from J.W.
Miller Magnetics (part # 78FR--k) were used for optimizing
the performance of the device in the NSC application board.
The values shown in
Figure 9 can be used as a good starting
point for the evaluation of the LM2465. Using a variable
resistor for R1 will simplify finding the value needed for
optimum performance in a given application. Once the
optimum value is determined, the variable resistors can be
replaced with fixed values.
EFFECT OF LOAD CAPACITANCE
Figure 8 shows the effect of increased load capacitance on
the speed of the device. This demonstrates the importance
of knowing the load capacitance in the application. The rise
time increased about 0.12nsec for an increase of 1pF in the
load capacitance. The fall time increased about 0.10 nsec for
a 1pF increase in the load capacitance.
EFFECT OF OFFSET
Figure 7 shows the variation in rise and fall times when the
output offset of the device is varied from 40 to 50 V
DC. The
rise time increases less than 0.20nsec from its fastest point
near 45V. The fall time becomes faster as the offset voltage
increases, but the 45V offset is only 0.1nsec slower than the
fastest fall time.
THERMAL CONSIDERATIONS
Figure 4 shows the performance of the LM2465 in the test
circuit shown in
Figure 2 as a function of case temperature.
The figure shows that the rise time of the LM2465 increases
by approximately 13% as the case temperature increases
from 30˚C to 95˚C. This corresponds to a speed degradation
of 2% for every 10˚C rise in case temperature. The fall time
degrades around 0.3% for every 10˚C rise in case
temperature.
Figure 6 shows the maximum power dissipation of the
LM2465 vs. Frequency when all three channels of the device
are driving an 8pF load with a 40V
p-p alternating one pixel
on, one pixel off signal. The graph assumes a 72% active
time (device operating at the specified frequency) which is
typical in a monitor application. The other 28% of the time
the device is assumed to be sitting at the black level (65V in
this case). This graph gives the designer the information
needed to determine the heat sink requirement for his
application. The designer should note that if the load
capacitance is increased, the AC component of the total
power dissipation will also increase.
The LM2465 case temperature must be maintained below
100˚C. If the maximum expected ambient temperature is
70˚C and the maximum power dissipation is 7.6W (from
Figure 6, 75MHz bandwidth) then a maximum heat sink
thermal resistance can be calculated:
This example assumes a capacitive load of 8pF and no
resistive load.
TYPICAL APPLICATION
A typical application of the LM2465 is shown in
Figure 10
and
Figure 11. Used in conjunction with an LM1267 and a
LM2479/2480bias clamp, a complete video channel from
monitor input to CRT cathode can be achieved. Performance
is ideal for 1280 x 1024 resolution displays with pixel clock
frequencies up to 135 MHz.
Figure 10 and Figure 11 are the
schematic for the NSC demonstration board that can be
used to evaluate the LM1267/2465 /2480 combination in a
monitor.
PC BOARD LAYOUT CONSIDERATIONS
For optimum performance, an adequate ground plane,
isolation between channels, good supply bypassing and
minimizing unwanted feedback are necessary. Also, the
length of the signal traces from the preamplifier to the
LM2465 and from the LM2465 to the CRT cathode should be
as
short
as
possible. The
following
references
are
recommended:
Ott, Henry W., “Noise Reduction Techniques in Electronic
Systems”, John Wiley & Sons, New York, 1976.
“Video Amplifier Design for Computer Monitors”, National
Semiconductor Application Note 1013.
Pease,
Robert A.,
“Troubleshooting Analog
Circuits”,
Butterworth-Heinemann, 1991.
Because of its high small signal bandwidth, the part may
oscillate in a monitor if feedback occurs around the video
channel through the chassis wiring. To prevent this, leads to
the video amplifier input circuit should be shielded, and input
circuit wiring should be spaced as far as possible from output
circuit wiring.
DS200190-10
FIGURE 9. One Channel of the LM2465 with the Recommended Arc Protection Circuit
www.national.com
6


Ähnliche Teilenummer - LM2465

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
National Semiconductor ...
LM2465 NSC-LM2465 Datasheet
1Mb / 43P
   150 MHz I2C Compatible RGB Preamplifier with Internal 254 Character OSD ROM, 512 Character RAM and 4 DACs
More results

Ähnliche Beschreibung - LM2465

HerstellerTeilenummerDatenblattBauteilbeschribung
logo
National Semiconductor ...
LM2415 NSC-LM2415 Datasheet
459Kb / 10P
   Monolithic Triple 5.5 ns CRT Driver
LM2435 NSC-LM2435 Datasheet
478Kb / 10P
   Monolithic Triple 5.5 ns CRT Driver
LM2470 NSC-LM2470 Datasheet
841Kb / 14P
   Monolithic Triple 7.0 ns CRT Driver
LM2405 NSC-LM2405 Datasheet
191Kb / 7P
   Monolithic Triple 7 ns CRT Driver
LM2439 NSC-LM2439 Datasheet
527Kb / 9P
   Monolithic Triple 9.5 ns CRT Driver
LM2402 NSC-LM2402 Datasheet
816Kb / 11P
   Monolithic Triple 3 ns CRT Driver
LM2412 NSC-LM2412 Datasheet
815Kb / 11P
   Monolithic Triple 2.8 ns CRT Driver
logo
Texas Instruments
LM2445 TI1-LM2445 Datasheet
1Mb / 15P
[Old version datasheet]   Monolithic Triple 7.5 ns CRT Driver
logo
National Semiconductor ...
LM2412A NSC-LM2412A Datasheet
818Kb / 11P
   Monolithic Triple 2.8 ns CRT Driver
LM2445 NSC-LM2445 Datasheet
758Kb / 14P
   Monolithic Triple 7.5 ns CRT Driver
More results


Html Pages

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


Datenblatt Download

Go To PDF Page


Link URL




Privatsphäre und Datenschutz
ALLDATASHEETDE.COM
War ALLDATASHEET hilfreich?  [ DONATE ] 

Über Alldatasheet   |   Werbung   |   Kontakt   |   Privatsphäre und Datenschutz   |   Linktausch   |   Hersteller
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