APPLICAT ION INFORMATION
The CVA2419TX is a high voltage triple CRT driver suitable
for VGA, S uper VGA, IBM 8514 1280 x 1024 and 1024 x 768
non-interlaced display applications. The CVA2419TX fe ature s
80V operation and low power dissipation. The part is housed
in the industry standard 11 lead TO-220 molded power
package. The heat sink is floating and may be grounded for
ease of manuf acturing an d RFI shielding.
Thermal Consi de rati ons
The transfer characteristics of the amplifier are shown in
Figure 2.
Since this is a class A input stage, power supply
current increases as the input signal increases and
consequently power dissipation also increases. Average
dissipation per s tage is 2.5W, increasing to 4.4W at minimum
output voltage.
The CVA2419TX cannot be used without heat sinking.
Figure
2
shows the power dissipated in each channel over the
operating voltage range of the device, Typical "average"
power dissipation with the device output voltage at one half
the supply voltage is 2.5W per channel for a to tal dissipation
of 7.5W package dissipation. Under white screen conditions,
i.e.: 20V output, dissipation increases to 5. 4W per channel or
16W total. The CVA2419TX case temperature must be
maintained below +90oC. If the maximum expected ambient
tem per atur e is + 5 0oC, then a heat s ink is ne ede d with t her m al
resist anc e equal to or less than:
R
th = (90 − 50oC)
16W = 2.5oC/W
The Thermalloy #14754 is one example of a heatsink that
meet s this r equirem en t.
The output of CVA2419TX is not short circuit proof. Any
resist anc e to V+ or Gr ound should be > 600Ω.
FALL TIME
VOLTS
10V/DIV
5ns/DIV
20V
80V
BANDWIDTH
100
MHz
110
GAIN
5dB/DIV
0dB
RISE TIM E
VOLTS
10V/DIV
5ns/DIV
20V
80V
FIGURE 3.
FIGURE 2. CVA2419TX DC Characterist ics
CVA2419TX
CALOGIC CORPORATION, 237 W hitney Place, F rem o nt , Califo r nia 94 539, Tele phone: 5 10 - 65 6- 2 900, FAX: 510-6 51 - 10 76
INPUT VOLTAGE
OUTPUT VOLTAGE (VOLTS)
0
60
90
35
7
POWER DISSIPATION (WATTS)
1462
50
80
40
70
30
20
10
VOLTAGE POWER 3
4
2
1
5
CORPORATION