NSC LM2465TA Datasheet

LM2465
Monolithic Triple 5.5 ns High Gain CRT Driver

General Description

The LM2465 is an integrated high voltage CRT driver circuit
designed for use in color monitor applications. The IC
contains three high input impedance, wide band amplifiers
which directly drive the RGB cathodes of a CRT. Each
channel has its gain internally set to −20 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 an industry standard 9-lead TO-220
molded plastic package.

Features

n Higher gain to match LM126X CMOS preamplifiers
n 0V to 3.75V input range
n Stable with 0–20 pF capacitive loads and inductive

peaking networks

n Same pinout as LM2467/8/9, maintaining the standard

LM243X Family pinout for easy PCB layout

n Convenient TO-220 staggered lead package style

Applications

n Up to 1280 x 1024 at 75Hz
n Pixel clock frequencies up to 135 MHz
n Monitors using video blanking

Schematic and Connection Diagrams

DS200190-1

FIGURE 1. Simplified Schematic Diagram

(One Channel)

DS200190-2

Note: TabisatGND

Top View

Order Number LM2465TA

March 2001

LM2465 Monolithic Triple 5.5 ns High Gain CRT Driver

© 2001 National Semiconductor Corporation DS200190 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

) +90V

Bias Voltage (V

BB

) +16V

Input Voltage (V

IN

) 0V to 4.5V

Storage Temperature Range (T

STG

) −65˚C to +150˚C

Lead Temperature

(Soldering,

<

10 sec.) 300˚C

ESD Tolerance, Human Body Model 2 kV

Machine Model 250V

Operating Ranges (Note 2)

V

CC

+60V to +85V

V

BB

+8V to +15V

V

IN

+0V to +3.75V

V

OUT

+15V to +75V
Case Temperature −20˚C to +100˚C
Do not operate the part without a heat sink.

Electrical Characteristics

(See

Figure 2

for Test Circuit)

Unless otherwise noted: V

CC

= +80V, VBB= +12V, CL= 8 pF, TC= 50˚C

DC Tests: V

IN

= 2.25VDC

AC Tests: Output = 40V

PP

(25V - 65V) at 1MHz

Symbol Parameter Conditions

LM2465

Units

Min Typical Max

I

CC

Supply Current All Three Channels, No Input Signal,

No Output Load

36 44 mA

I

BB

Bias Current All Three Channels 20 24 mA

V

OUT

DC Output Voltage No AC Input Signal, VIN= 1.25V 62 65 68 V

DC

A

V

DC Voltage Gain No AC Input Signal −18 −20 −22

∆A

V

Gain Matching (Note 4), No AC Input Signal 1.0 dB
LE Linearity Error (Notes 4, 5), No AC Input Signal 5 %
t

R

Rise Time (Note 6), 10% to 90% 5.5 ns
t

F

Fall Time (Note 6), 90% to 10% 6.0 ns
OS Overshoot (Note 6) 3 %

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. Forguaranteedspecificationsand

test conditions, see the Electrical Characteristics. 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: Calculated value from Voltage Gain test on each channel.
Note 5: Linearity Error is the variation in dc gain from V

IN

= 1.0V to VIN= 3.5V.

Note 6: Input from signal generator: t

r,tf

<

1 ns.

LM2465

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AC Test Circuit

Figure 2

shows a typical test circuit for evaluation of the LM2465. This circuit is designed to allow testing of the LM2465 in a 50Ω
environment without the use of an expensive FET probe. The two 2490Ω resistors form a 200:1 divider with the 50Ω resistor and
the oscilloscope. A test point is included for easy use of an oscilloscope probe.The compensation capacitor is used to
compensate the stray capacitance of the two 2490Ω resistors to achieve flat frequency response.

DS200190-3

Note: 8 pF load includes parasitic capacitance.

FIGURE 2. Test Circuit (One Channel)

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Typical Performance Characteristics (V

CC

= +80VDC,VBB= +12VDC,CL= 8pF, V

OUT

= 40V

PP

(25V−65V), Test Circuit -

Figure 2

unless otherwise specified)

DS200190-4

FIGURE 3. V

OUT

vs V

IN

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FIGURE 4. Speed vs Temperature

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FIGURE 5. LM2465 Pulse Response

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FIGURE 6. Power Dissipation vs Frequency

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FIGURE 7. Speed vs Offset

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FIGURE 8. Speed vs Load Capacitance

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