|
|
PDF LM2419T Data sheet ( Hoja de datos )
| Número de pieza | LM2419T | |
| Descripción | Triple 65 MHz CRT Driver | |
| Fabricantes | National Semiconductor | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de LM2419T (archivo pdf) en la parte inferior de esta página. Total 8 Páginas | ||
|
No Preview Available !
December 1994
LM2419
Triple 65 MHz CRT Driver
General Description
The LM2419 contains three wide bandwidth large signal
amplifiers designed for large voltage swings The amplifiers
have a gain of b15 The device is intended for use in color
CRT monitors and is a low cost solution to designs conform-
ing to 1024 x 768 display resolution
The device is mounted in the industry standard 11-lead
TO-220 molded power package The heat sink is electrically
isolated and may be grounded for ease of manufacturing
and EMI RFI shielding
Features
Y 50 VPP output swing at 65 MHz
Y Rise Fall time 5 ns with 12 pF load
Y 60 VPP output swing capability
Y Pin and function compatible with LM2416
Y No low frequency tilt compensation required
Applications
Y CRT driver for SVGA IBM 8514 and 1024 x 768
display resolution RGB monitors
Schematic and Connection Diagrams
One Channel
TL H 11442 – 1
TL H 11442 – 2
Order Number LM2419T
See NS Package Number TA11B
C1995 National Semiconductor Corporation TL H 11442
RRD-B30M115 Printed in U S A
1 page  
Application Hints (Continued)
THERMAL CONSIDERATIONS
LM2419’s transfer characteristic and power dissipation ver-
sus DC input voltage is shown in Figure 5 Power supply
current increases as the input voltage increases conse-
quently power dissipation increases For the LM2419 the
worst case power dissipation occurs when a white screen is
displayed on the CRT Considering a 20% black retrace
time in a 1024 x 768 display resolution application the aver-
age power dissipation for continuous white screen is less
than 4W per channel with 50 VPP output signal (black level
at 75V and white level at 25V) Although the total power
dissipation is less than 12W for a continuous white screen
the heat sink should be selected for 13W power dissipation
because of the variation in power dissipation from part to
part
For thermal and gain linearity considerations the output low
voltage (white level) should be maintained above 20V If the
device is operated at an output low voltage below 20V the
power dissipation might exceed 4 7W per channel (i e 14W
power dissipation for the device) Note that the device can
be operated at lower power by reducing the peak to peak
video output voltage to less than 50V and clamping the vid-
eo black level close to the supply voltage
TL H 11442 – 10
FIGURE 5 VOUT and Power Dissipation vs VIN
The LM2419 requires that the package be properly heat
sunk under all operating conditions Maximum ratings re-
quire that the device case temperature be limited to 90 C
maximum Thus for 50 C maximum ambient temperature
and 13W maximum power dissipation the thermal resist-
ance of the heat sink should be
isa s (90 – 50) C 13W e 3 C W
SHORT CIRCUIT PROTECTION
The output of LM2419 is not short circuit protected Short-
ing the output to either ground or to Va will destroy the
device The minimum DC load resistance the LM2419 can
drive without damage is 1 6 kX to ground or Va However
driving a 1 6 kX load for an extended period of time is not
recommended because of power dissipation considera-
tions If the LM2419 is used to drive a resistive load then the
load should be 10 kX or greater
RGB Video Application
A complete video section for an RGB CRT monitor is shown
in Figure 6 The LM1203 video preamplifier and the LM2419
include almost all the circuitry required between the video
input connection and the CRT’s cathodes However an ex-
ternally generated back porch clamp signal is required to
accomplish DC restoration of the video signal
Figure 6 ’s circuit is excellent choice for a non-interlaced
1024 x 768 display resolution application With 50 VPP out-
put swing and 12 pF load the rise fall time for Figure 6 ’s
circuit was measured at 7 5 ns In this application feedback
is local to the LM1203 For detailed information on the
LM1203 please refer to the LM1203 data sheet
PC BOARD LAYOUT CONSIDERATIONS
For optimum performance adequate ground plane isolation
between channels good supply bypassing and minimizing
unwanted feedback are necessary Moreover the length of
the signal trace from the preamplifier to the LM2419 and
from the LM2419 to the cathode should be as short as is
practical The following book is highly recommended
Ott Henry W Noise Reduction Techniques in Electronic
Systems John Wiley Sons New York 1976
5
5 Page | ||
| Páginas | Total 8 Páginas | |
| PDF Descargar | [ Datasheet LM2419T.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| LM2419 | Triple 65 MHz CRT Driver | National Semiconductor |
| LM2419 | LM2419 Triple 65 MHz CRT Driver (Rev. A) |  Texas Instruments |
| LM2419T | Triple 65 MHz CRT Driver | National Semiconductor |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |