Improved
Low Cost Triple
CRT Driver
CVA2411TX
FEATURES
Ease of Use
Small Heat Sink
OSD Option
EMI Control Option
Excellent Gray Scale Linearity
APPLICATIONS
CRT Displays for 1280 x 1024 Resolution with Pixel
Clock Frequency up to 160MHz
DESCRIPTION
The CVA2411TX is an improved low cost version that features
excellent gray scale linearity with no crossover distortion and
less EMI for 69kHz (horizontal scanning frequency) monitors.
The CVA2411TX can be used with pre-amplifiers where the
common emitter transistor is part of the pre-amp. With this
device, OSD, peaking coil, and peaking capacitor can be
available. A very small heat sink is required to pick-up ground
from the standard TO220 package Tab. With 65MHz
bandwidth, the device is an ideal low cost solution for 14", 15"
and 17" monitors.
ORDERING INFORMATION
Part
Package
Temperature
CVA2411TX
T11A
-20
o
C to +100
o
C
CORPORATION
CONNECTION DIAGRAM AND SIMPLIFIED SCHEMATIC
1H-39
3,6,9
2,5,10
COLLECTOR
1
V
BIAS
V
OUT
11
V
CC
TAB
Q3
EMITTER
4,7,8
V
OUT
11
10
9
8
7
6
5
4
3
2
1
BIAS
TAB = GND
V
COLLECTOR 1
EMITTER 3
EMITTER 2
COLLECTOR 2
EMITTER 1
COLLECTOR 3
V
1B-17
CC
OUT
V
OUT
V
TOP VIEW
T11A PACKAGE
3
2
1
CALOGIC CORPORATION,
237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
ABSOLUTE MAXIMUM RATINGS
Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95V
Storage Temperature . . . . . . . . . . . . . . . . . . . -25
o
C to +125
o
C
Maximum Current (Q3) . . . . . . . . . . . . . . . . . . . . . . . . . . 60mA
Operating Temperature . . . . . . . . . . . . . . . . . -20
o
C to +100
o
C
Lead Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300
o
C
CVA2411TX
AC/DC CHARACTERISTICS T
CASE
= +25
o
C
SYMBOL
CHARACTERISTICS
MIN
TYP
MAX
UNITS
BV
CEO
Collector-Emitter Breakdown Voltage (I
c
= 1mA)
95
V
BV
CBO
Collector-Base Breakdown Voltage (I
c
= 100
A)
100
V
BV
EBO
Emitter-Base Breakdown Voltage (I
E
= 100
A)
3
V
H
FE
DC Current Gain (I
c
= 50mA)
25
35
--
V
BES
Base-Emitter Saturation Voltage
0.95
V
V
CES
Collector-Emitter Saturation Voltage
0.3
V
V
BE(ON)
Base-Emitter ON Voltage
0.6
V
I
CEO
Collector Cut-Off Current
100
nA
C
ob
Output Capacitance
3
pF
C
cb
Junction Capacitance
2
pF
C
i b
Input Capacitance
8
pF
f
t
Current Gain Bandwidth Product (I
c
= 35mA)
150
MHz
AC/DC CHARACTERISTICS of Amplifier (See test circuit) T
CASE
= +25
o
C, V
CC
= 80V, V
IN
= 3.2V, unless otherwise specified.
SYMBOL
CHARACTERISTCS
MIN
TYP
MAX
UNITS
I
CC
Supply Current
30
38
mA
V
OUT
Output Voltage, V
IN
= 3.6V
45
52
V
A
V
Gain
13
15
V/V
T
r
Rise Time, V
OUT
= 45V
P-P
, C
LOAD
= 10pF
9.5
11
ns
T
f
Fall Time, V
OUT
= 45V
P-P
, C
LOAD
= 10pF
8
9
ns
Overshoot
5
%
120pF
4,7,8
1S-22
CVA2411TX
2,5,10
11
11
3,6,9
12V
1
1.2K
9
10pF
65
9
50
9
33
9
V
IN
CALOGIC CORPORATION,
237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
FIGURE 1. TEST CIRCUIT
CORPORATION
APPLICATION INFORMATION
The CVA2411TX consists of three identical transistor arrays that
includes cascode transistor, push pull output stage and biased
diodes for no cross-over distortion. This design technique makes
the CVA2411TX an ideal candidate for a CRT driver application.
Used with an external emitter follower, such as the 2N2369, and
a load resistor (~1.2K
, 3W), the CVA2411TX works well in a
69kHz (1280 x 1024 non-interlaced) monitor application.
For power and cost effective applications, CVA2411TX is the
ideal solution. The CVA2411TX requires a very small heat
sink as the majority of the power is dissipated in load
resistors. The emiitter peaking option maximizes the high
frequency gain.
In the following pages a full schematic and the picture of a
demo board are provided, demonstrating that the CVA2411TX
works well for 69kHz monitors. See characteristics taken at
the cathode of the monitor.
Thermal Considerations
The transfer characteristics of the CVA2411TX application
(
Figure 2.) are shown in Figure 3. Since this is a class A input
stage, power supply current increases as the input signal
increases and consequently power dissipation also increases.
The CVA2411TX cannot be used without a heat sink as the
tab is grounded and also the case temperature should be
maintained at less than 100
o
C. Under white screen condition,
i.e. 25V output, dissipation is 0.6W/channel. Under gray level
conditions C
L
= 8pf, V
OUT
= 45
P-P
, the dissipation is
1.6W/channel. If the maximum expected ambient temperature is
+50
o
C, then a heat sink is needed with thermal resistance
equal to or less than:
R
th
=
(
100
-
50
o
C
)
4.8W
=
10.4
o
C/W
The CVA2411TX maximum load is 600
to ground or V
+
.
The output of CVA2411TX is not short circuit proof. Any
resistance to V
+
or Ground should be more than 600
.
FIGURE 3. CVA2411TX TRANSFER CHARACTERISTICS
CALOGIC CORPORATION,
237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CVA2411TX
V (VOLTS)
IN
80
70
60
50
40
30
20
10
0
1S-15
Q3 POWER
Power/Output Stage
V
OUT
2.5
2.0
1.5
1.0
0.5
0
0
0.
2
0.
5
0.
7
1.
0
1.
2
1.
5
1.
7
2.
0
2.
2
2.
5
2.
7
3.
0
3.
2
3.
5
3.
7
4.
0
4.
2
4.
5
4.
7
5.
0
5.
2
5.
5
5.
7
6.
0
V
(
V
)
OU
T
P
O
W
E
R (W
)
CORPORATION
TYPICAL CHARACTERISTICS
CALOGIC CORPORATION,
237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CVA2411TX
V
vs FREQUENCY
OUT
V
(
V
)
O
U
T
P-P
60
50
40
30
20
10
0
1S-16
10
FREQUENCY (MHz)
20
30
50
70
80
90
I
vs FREQUENCY
CC
70
60
50
40
30
20
10
0
1S-17
1.0 1.11
FREQUENCY (MHz)
1.25 1.42 1.66 2.0
2.5
3.33 5.0 10.0 11.11 12.5 14.2 16.6 20.0 25.0 33.3 50.0 80.0
I
(
m
A)
CC
CORPORATION
CALOGIC CORPORATION,
237 Whitney Place, Fremont, California 94539, Telephone: 510-656-2900, FAX: 510-651-3025
CVA2411TX
1S-21
20ns/DIV
10V/DI
V
CROSS HATCH
WHITE BACKGROUND
2.4ns
202.4ns
-5.5V
4.5V
1S-20
20ns/DIV
10V/DI
V
CROSS HATCH
BLACK BACKGROUND
-83.6ns
116.4ns
-5.5V
4.5V
1S-19
20ns/DIV
10V/DIV
FALL TIME
-45.6ns
154.4ns
-5.5V
4.5V
1S-18
20ns/DIV
10V/DIV
RISE TIME
-83.6ns
116.4ns
-5.5V
4.5V
TYPICAL CHARACTERISTICS (continued)
CORPORATION
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