LM2459
Monolithic Single Channel 15 MHz DTV CRT Driver
General Description
The LM2459 is a single channel high voltage CRT driver
circuit designed for use in DTV applications. The IC contains
a high input impedance, wide band amplifier which directly
drives the cathode of a CRT. The amplifier has its gain
internally set to -51 and can drive CRT capacitive loads as
well as resistive loads present in other applications, limited
only by the package's power dissipation.
The IC is packaged in a staggered 7-lead TO-220 molded
plastic power package designed specifically to meet high
voltage spacing requirements. See Thermal Considerations
section.
Features
n
15MHz bandwith at 130V
PP
output swing
n
0V to 4V input range
n
Greater than 130V
PP
output swing capability
n
Stable with 020 pF capacitive loads and inductive
peaking networks
n
Transient response improvement option via pin 6 (EM)
Applications
n
AC coupled DTV applications using the 480p format as
well as standard NTSC and PAL formats.
Connection Diagram
Schematic Diagram
20067802
Note: Tab is at GND
Top View
Order Number LM2459TE
FIGURE 1. Simplified Connection and Pinout Diagram
20067801
FIGURE 2. Simplified Schematic Diagram
May 2004
LM2459
Monolithic
Single
Channel
15
MHz
DTV
CRT
Driver
2004 National Semiconductor Corporation
DS200678
www.national.com
Absolute Maximum Ratings
(Notes 1,
3)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Supply Voltage (V
CC
)
+200V
Bias Voltage (V
BB
)
+15V
Input Voltage (V
IN
)
-0.5V to V
BB
+0.5V
Storage Temperature Range (T
STG
)
-65C to +150C
Lead Temperature
(Soldering,
<
10 sec.)
300C
ESD Tolerance,
Human Body Model
2kV
Machine Model
200V
Junction Temperature
150C
JC
(typ)
4.2C/W
Operating Ranges
(Note 2)
V
CC
+130V to +180V
V
BB
+7V to +13V
V
IN
+0V to +4V
V
OUT
+25V to +178V
Case Temperature
Refer to Figure 11
Do not operate the part without a heat sink.
Electrical Characteristics
(See Figure 3 for Test Circuit)
Unless otherwise noted: V
CC
= +180V, V
BB
= +8V, C
L
= 10pF, T
C
= 30C, Pin 6 floating.
DC Tests: V
IN
= 2.5V
DC
AC Tests: Output = 130V
PP
(35V - 165V) at 1MHz
Symbol
Parameter
Conditions
LM2459
Units
Min
Typical
Max
I
CC
Supply Current
No AC Input Signal, No Output Load
6
12
mA
I
BB
Bias Current
4
7
mA
V
OUT, 1
DC Output Voltage
No AC Input Signal, V
IN
= 2.5V
DC
99
104
109
V
DC
V
OUT, 2
DC Output Voltage
No AC Input Signal, V
IN
= 1.2V
DC
165
170
175
V
DC
A
V
DC Voltage Gain
No AC Input Signal
-48
-51
-54
LE
Linearity Error
(Note 4), No AC Input Signal
5
%
t
R
Rise Time
(Note 5), 10% to 90%
26
ns
t
F
Fall Time
(Note 5), 90% to 10%
30
ns
OS
Overshoot
(Note 5)
5
%
Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Note 2: Operating ratings indicate conditions for which the device is functional, but do not guarantee specific performance limits. For guaranteed specifications and
test conditions, see the Electrical Characteristics. Datasheet min/max specification limits are guaranteed by design, test, or statistical analysis. The guaranteed
specifications apply only for the test conditions listed. Some performance characteristics may change when the device is not operated under the listed test
conditions.
Note 3: All voltages are measured with respect to GND, unless otherwise specified.
Note 4: Linearity Error is the variation in DC gain from V
IN
= 1.1V to V
IN
= 3.8V.
Note 5: Input from signal generator: t
r
, t
f
<
1 ns.
LM2459
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2
AC Test Circuit
Figure 3 shows a typical test circuit for evaluation of the LM2459. This circuit is designed to allow testing of the LM2459 in a 50
environment without the use of an expensive FET probe. The two 4990
resistors form a 400:1 divider with the 50 resistor and
the oscilloscope. A test point is included for easy use of an oscilloscope probe.The compensation capacitor is used to
compensate the network to achieve a flat frequency response.
20067803
Note: 10pF load includes parasitic capacitance.
FIGURE 3. Test Circuit
LM2459
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3
Typical Performance Characteristics
(V
CC
= +180V
DC
, V
BB
= +8V
DC
, C
L
= 10pF, V
OUT
= 130V
PP
(35V - 165V), Test Circuit - Figure 3, Pin 6 floating, unless otherwise specified)
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FIGURE 4. V
OUT
vs V
IN
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FIGURE 5. LM2459 Pulse Response
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FIGURE 6. Bandwidth
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FIGURE 7. Speed vs Load Capacitance
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FIGURE 8. Speed vs Offset
20067809
FIGURE 9. Speed vs Case Temperature
LM2459
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4
Typical Performance Characteristics
(V
CC
= +180V
DC
, V
BB
= +8V
DC
, C
L
= 10pF, V
OUT
= 130V
PP
(35V - 165V), Test Circuit - Figure 3, Pin 6 floating, unless otherwise specified) (Continued)
20067807
FIGURE 10. Power Dissipation vs Frequency
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FIGURE 11. Power Derating Curve
20067819
FIGURE 12. Cathode Pulse Response
LM2459
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5
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