lm1207.pdf

October 1993

LM1205

130 MHz RGB Video Amplifier System with Blanking

General Description

The LM1205 is a very high frequency video amplifier system

intended for use in high resolution RGB monitor applica-

tions. In addition to the three matched video amplifiers, the

LM1205 contains three gated single ended input black level

clamp comparators for brightness control, three matched

DC controlled attenuators for contrast control, and three DC

controlled sub-contrast attenuators providing gain trim ca-

pability for white balance. All DC control inputs offer high

input impedance and an operation range from 0V to 4V for

easy interface to bus controlled alignment systems. The

LM1205 also contains a blanking circuit which clamps the

video output voltage during blanking to within 0.1V of

ground. This feature provides blanking capability at the

cathode of the CRT.

Y Three externally gated single ended input comparators

for cutoff and brightness control

Y Provisions for individual gain control (Drive) of each

video amplifier

Y 0V to 4V, high input impedance DC contrast control

( l 40 dB range)

Y 0V to 4V, high input impedance DC drive control

( g 3 dB range)

Y Capable of 7 V PP output swing (slight reduction in

bandwidth)

Y Output stage blanking

Y Output stage directly drives most hybrid or discrete

CRT drivers

Applications

Y High resolution RGB CRT monitors

Y Video AGC amplifiers

Y Wideband amplifiers with gain and DC offset controls

Y Interface amplifiers for LCD or CCD systems

Features

Y Three wideband video amplifiers 130 MHz @ b 3dB

(4 V PP output)

Y Matched ( g 0.1 dB or 1.2%) attenuators for contrast

control

Block and Connection Diagram

TL/H/11831±24

FIGURE 1

Order Number LM1205N

See NS Package Number N28B

C 1995 National Semiconductor Corporation

TL/H/11831

RRD-B30M115/Printed in U. S. A.

Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,

please contact the National Semiconductor Sales

Office/Distributors for availability and specifications.

Supply Voltage (V CC )

Pins 3, 11, 22, 23, 25 (Note 3)

Operating Ratings (Note 2)

Temperature Range

b 20 § Cto80 § C

Supply Voltage (V CC )

10.8V s V CC s 13.2V

13.5V

Peak Video Output Source Current

(Any One Amp) Pins 17, 20 or 26

28 mA

Voltage at Any Input Pin (V IN )

V CC t V IN t GND

Power Dissipation (P D )

(Above 25 § C Derate Based on i JA and i J )

2.5W

Thermal Resistance ( i JA )

50 § C/W

Junction Temperature (T J )

150 § C

ESD Susceptibility (Note 4)

2 kV

Pins 13 and 14

1 kV

Storage Temperature

b 65 § Cto150 § C

Lead Temperature (Soldering, 10 sec.)

265 § C

DC Electrical Characteristics See DC Test Circuit (Figure2), T A e 25 § C; V CC1 e V CC2 e 12V. V 12 e 4V;

V 14 e 0V; V cut-off e 1.0V; V 13 e 4V; V drive e 4V unless otherwise stated.

Symbol

Parameter

Conditions

Typical Limit

Units

(Note 5) (Note 6)

I S

Supply Current

V CC1 a V CC2 ,R L e % (Note 7)

105 mA (max)

V 4, 6, 9

Video Amplifier Input Bias Voltage

2.8

R IN

Video Input Resistance

Any One Amplifier

k X

V 14l

Clamp Gate Low Input Voltage

Clamp Comparators On

1.2

0.8

V (max)

V 14h

Clamp Gate High Input Voltage

Clamp Comparators Off

1.6

2.0

V (min)

I 14l

Clamp Gate Low Input Current

V 14 e 0V

b 1 b 5.0 m A (max)

I 14h

Clamp Gate High Input Current

V 14 e 12V

0.01

1.0 m A (max)

I clamp

Clamp Cap Charge Current

Clamp Comparators On

g 750 g 500 m A (min)

I bias

Clamp Cap Bias Discharge Current

Clamp Comparators Off

500

V 13l

Blank Gate Low Input Voltage

Blank Gate On

1.2

0.8

V (max)

V 13h

Blank Gate High Input Voltage

Blank Gate Off

1.6

2.0

V (min)

I 13l

Blank Gate Low Input Current

V 13 e 0V

b 1 b 5.0 m A (max)

I 13h

Blank Gate High Input Current

V 13 e 12V

0.01

1.0 m A (max)

V OL

Video Output Low Voltage

V cut-off e 0V

0.15

0.5

V (max)

V OH

Video Output High Voltage

V cut-off e 9V

7.5

V (min)

V O(1V)

Video Black Level Output Voltage

V cut-off e 1V

0.9

V (Note 8)

D V O(1V)

Video D Blank Level Output Voltage

Between Any Two Amplifiers,

g 100

mV (max)

V cut-off e 1V

V OL (blanked) Video Output Blanked Voltage

V 13 e 0V

I 12, 15, 18 or 28 Contrast/Drive Control Input Current V contrast e V drive e 0V to 4V b 250

I 16, 19 and 27 Cut-Off Control Input Current (All Inputs) V cut-off e 0V to 4V

b 500

AC Electrical Characteristics See AC Test Circuit (Figure3),T A e 25 § C; V CC1 e V CC2 e 12V. Manually

adjust Video Output pins 17, 20, and 26 to 4V DC for the AC test unless otherwise stated. (Note 15).

Symbol

Parameter

Conditions

Typical

Limit

Units

(Note 5)

(Note 6)

A V max

Video Amplifier Gain

V12 e 4V, V IN e 635 mV PP

7.0

5.4

V/V (min)

V drive e 4V

16.9

14.6

dB (min)

D A V2V

Attenuation @ 2V

Ref: A V max, V12 e 2V

b 6

D A V 0.5V

Attenuation @ 0.5V

Ref: A V max, V12 e 0.5V

b 38

D Drive

Drive Control Range

V drive e 0V to 4V, V12 e 4V

A V match

Absolute Gain Match @ A V max V12 e 4V, V drive e 4V (Note 9)

g 0.3

A V track1

Gain Change Between Amplifiers V12 e 4V to 2V (Notes 9, 10) g 0.1

THD

Video Amplifier Distortion

V O e 1V PP ,f e 10 kHz

f( b 3 dB)

Video Amplifier Bandwidth

V12 e 4V, V drive e 4V,

130

MHz

(Notes 11, 12)

V O e 4V PP

t r (Video)

Video Output Rise Time (Note 11) V O e 4V PP

2.6

t f (Video)

Video Output Fall Time (Note 11) V O e 4V PP

3.6

V sep 10 kHz Video Amplifier 10 kHz Isolation V12 e 4V (Note 13)

b 70

V sep 10 MHz Video Amplifier 10 MHz Isolation V12 e 4V (Notes 11, 13)

b 50

t r (Blank)

Blank Output Rise Time (Note 11) Blank Output e 1V PP

t f (Blank)

Blank Output Fall Time (Note 11) Blank Output e 1V PP

t pw (Clamp) Back Porch Clamp Pulse Width

(Note 14)

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. The guaranteed specifications apply only for the test conditions listed. Some performance characteristics

may degrade when the device is not operated under the listed test conditions.

Note 3: V CC supply pins 3, 11, 22, 23, 25 must be externally wired together to prevent internal damage during V CC power on/off cycles.

Note 4: Human body model, 100 pF discharged through a 1.5 k X resistor.

Note 5: Typical specifications are specified at a 25 § C and represent the most likely parametric norm.

Note 6: Tested limits are guaranteed to National's AOQL (Average Outgoing Quality Level).

Note 7: The supply current specified is the quiescent current for V CC1 and V CC2 with R L e % , see Figure2's test circuit. The supply current for V CC2 (pin 23) also

depends on the output load. With video output at 1V DC, the additional current through V CC2 is8mAforFigure2's test circuit.

Note 8: Output voltage is dependent on load resistor. Test circuit uses R L e 390 X .

Note 9: Measure gain difference between any two amplifiers. V IN e 635 mV PP .

Note 10: D A V track is a measure of the ability of any two amplifiers to track each other and quantifies the matching of the three attenuators. It is the difference in

gain change between any two amplifiers with the contrast voltage (V12) at either 4V or 2V measured relative to an A V max condition, V12 e 4V. For example, at A V

max the three amplifiers' gains might be 17.1 dB, 16.9 dB and 16.8 dB and change to 11.2 dB, 10.9 dB, and 10.7 dB respectively for V12 e 2V. This yields the

measured typical g 0.1 dB channel tracking.

Note 11: When measuring video amplifier bandwidth or pulse rise and fall times, a double sided full ground plane printed circuit board without socket is

recommended. Video amplifier 10 MHz isolation test also requires this printed circuit board. The reason for a double sided full ground plane PCB is that large

measurement variations occur in single sided PCBs.

Note 12: Adjust input frequency from 10 MHz (A V max reference level) to the b 3 dB corner frequency (f b 3dB ).

Note 13: Measure output levels of the other two undriven amplifiers relative to the driven amplifier to determine channel separation. Terminate the undriven

amplifier inputs to simulate generator loading. Repeat test at f IN e 10 MHz for V sep 10 MHz .

Note 14: A minimum pulse width of 200 ns is guaranteed for a horizontal line of 15 kHz. This limit is guaranteed by design. If a lower line rate is used then a longer

clamp pulse may be required.

Note 15: During the AC tests the 4V DC level is the center voltage of the AC output signal. For example, if the output is 4 V PP the signal will swing between 2V DC

and 5V DC.

Typical Performance Characteristics (V CC e 12V, T A e 25 § C unless otherwise specified)

Attenuation vs Contrast Voltage

Attenuation vs Drive Voltage

TL/H/11831±1

TL/H/11831±2

Crosstalk vs Frequency

TL/H/11831±3

Contrast vs Frequency

TL/H/11831±4

Drive vs Frequency

TL/H/11831±5

Applications Information

TL/H/11831±6

FIGURE 2. LM1205N DC Test Circuit

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika: