NSC LM1203BN, LM1203AN Datasheet
TL/H/9178
LM1203 RGB Video Amplifier System
January 1996
LM1203 RGB Video Amplifier System
General Description
The LM1203 is a wideband video amplifier system intended
for high resolution RGB color monitor applications. In addition to three matched video amplifiers, the LM1203 contains
three gated differential input black level clamp comparators
for brightness control and three matched attenuator circuits
for contrast control. Each video amplifier contains a gain set
or ‘‘Drive’’ node for setting maximum system gain (Av
e
4
to 10) as well as providing trim capability. The LM1203 also
contains a voltage reference for the video inputs. For high
resolution monochrome monitor applications see the
LM1201 Video Amplifier System datasheet.
Features
Y
Three wideband video amplifiers (70 MHz
@
b
3dB)
Y
Inherently matched (g0.1 dB or 1.2%) attenuators for
contrast control
Y
Three externally gated comparators for brightness control
Y
Provisions for independent gain control (Drive) of each
video amplifier
Y
Video input voltage reference
Y
Low impedance output driver
Block and Connection Diagram
TL/H/9178– 1
FIGURE 1
Order Number LM1203N
See NS Package Number NA28F
C
1996 National Semiconductor Corporation RRD-B30M56/Printed in U. S. A.
Absolute Maximum Ratings
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage, V
CC
Pins 1, 13, 23, 28
(Note 1) 13.5V
Voltage at Any Input Pin, V
IN
V
CC
t
V
IN
t
GND
Video Output Current, I16, 20 or 25 28 mA
Power Dissipation, P
D
2.5W
(Above 25
§
C) Derate Based on iJAand T
J
Thermal Resistance, i
JA
50§C/W
Junction Temperature, T
J
150§C
Storage Temperature Range, T
STG
b
65§Ctoa150§C
Lead Temperature, (Soldering, 10 sec.) 265§C
ESD susceptibility 1 kV
Human body model: 100 pF discharged through a 1.5 kX
resistor
Operating Ratings (Note 9)
Temperature Range 0
§
Cto70§C
Supply Voltage (VCC) 10.8VsV
CC
s
13.2V
Electrical Characteristics See Test Circuit
(Figure 2)
,T
A
e
25§C; V
CC1
e
V
CC2
e
12V
DC Static Tests S17, 21, 26 Open; V12
e
6V; V14e0V; V15e2.0V unless otherwise stated
Label Parameter Conditions Typ
Tested Design Units
Limit (Note 2) Limit (Note 3) (Limits)
Is Supply Current VCC1 only 73 90.0 mA(max)
V11 Video Input Reference Voltage
2.4
2.2 V(min)
2.6 V(max)
lb Video Input Bias Current Any One Amplifier 5.0 20 mA(max)
V14 l Clamp Gate Low Input Voltage Clamp Comparators On 1.2 0.8 V(max)
V14 h Clamp Gate High Input Voltage Clamp Comparators Off 1.6 2.0 V(min)
I14 l Clamp Gate Low Input Current V14e0V
b
0.5
b
5.0 mA(max)
I14 h Clamp Gate High Input Current V14e12V 0.005 1 mA(max)
lclampaClamp Cap Charge Current V5, 8 or 10e0V 850 500 mA(min)
lclampbClamp Cap Discharge Current V5, 8 or 10e5V
b
850
b
500 mA(min)
Vol Video Output Low Voltage V5, 8 or 10e0V 0.9 1.25 V(max)
Voh Video Output High Voltage V5, 8 or 10e5V 8.9 8.2 V(min)
DVo(2V) Video Output Offset Voltage Between Any Two Amplifiers
g
0.5
g
50 mV(max)
V15
e
2V
DVo(4V) Video Output Offset Voltage Between Any Two Amplifiers
g
0.5
g
50 mV(max)
V15e4V
AC Dynamic Tests S17, 21, 26 Closed; V14
e
0V; V15e4V; unless otherwise stated
Symbol Parameter Conditions Typ
Tested Design Units
Limit (Note 2) Limit (Note 3) (Limits)
Av max Video Amplifier Gain V12e12V, V
IN
e
560 mVp-p 6.0 4.5 V/V(min)
DAv 5V Attenuation@5V Ref: Av max, V12e5V
b
10 dB
DAv 2V Attenuation@2V Ref: Av max, V12e2V
b
40 dB
Av match Absolute gain match@Av max V12e12V (Note 5)
g
0.5 dB
DAv track1 Gain change between amplifiers V12e5V (Notes 5, 8)
g
0.1
g
0.5 dB(max)
DAv track2 Gain change between amplifiers V12e2V (Notes 5, 8)
g
0.3
g
0.7 dB(max)
THD Video Amplifier Distortion V12e3V, V
O
e
1 Vp-p 0.5 %
f(b3 dB) Video Amplifier Bandwidth V12e12V,
70 MHz
(Notes 4, 6) V
O
e
100 mV
rms
t
r
Output Rise Time (Note 4) V
O
e
4 Vp-p 5 ns
t
f
Output Fall Time (Note 4) V
O
e
4 Vp-p 7 ns
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AC Dynamic Tests S17, 21, 26 Closed; V14
e
0V; V15e4V; unless otherwise stated (Continued)
Symbol Parameter Conditions Typ
Tested Design
Units
Limit (Note 2) Limit (Note 3)
Vsep Video Amplifier 10 kHz Isolation V12e12V (Note 7)
b
65 dB
10 kHz
Vsep Video Amplifier 10 MHz Isolation V12e12V (Notes 4, 7)
b
46 dB
10 MHz
Note 1: VCCsupply pins 1, 13, 23, 28 must be externally wired together to prevent internal damage during VCCpower on/off cycles.
Note 2: These parameters are guaranteed and 100% production tested.
Note 3: Design limits are guaranteed (but not 100% production tested). These limits are not used to calculate outgoing quality levels.
Note 4: When measuring video amplifier bandwidth or pulse rise and fall times, a double sided full ground plane printed circuit board without socket is recommend-
ed. Video Amplifier 10 MHz isolation test also requires this printed circuit board.
Note 5: Measure gain difference between any two amplifiers. V
IN
e
1 Vp-p.
Note 6: Adjust input frequency from 10 kHz (Av
max
ref level) to theb3 dB corner frequency (fb3 dB).
Note 7: Measure output levels of the other two undriven amplifiers relative to driven amplifier to determine channel separation. Terminate the undriven amplifier
inputs to simulate generator loading. Repeat test at f
IN
e
10 MHz for Vsepe10 MHz.
Note 8: DAv 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 5V or 2V measured relative to an Av max condition V12
e
12V. For example, at
Av max the three amplifiers gains might be 17.4 dB, 16.9 dB, and 16.4 dB and change to 7.3 dB, 6.9 dB, and 6.5 dB respectively for V12
e
5V. This yields the
measured typical
g
0.1 dB channel tracking.
Note 9: Operating Ratings indicate conditions for which the device is functional. See Electrical Specifications for guaranteed performance limits.
*Peaking capacitors. See Frequency Response
using various peaking cups graph on next page.
TL/H/9178– 2
FIGURE 2. LM1203 Test Circuit
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Typical Performance Characteristics
Contrast vs Frequency
TL/H/9178– 11
Crosstalk vs Frequency
TL/H/9178– 12
Frequency Response Using
Various Peaking Caps
TL/H/9178– 13
Attenuation vs Contrast Voltage
TL/H/9178– 14
Pulse Response
Rise & Fall Times
Vert.
e
1V/Div.
Horiz.
e
10 ns/Div.
– – GND
TL/H/9178– 15
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TL/H/9178– 3
FIGURE 3. LM1203 Typical Application
* 30X resistors are added to the input pins for protection against current surges coming through the 10 mF input capacitors. By increasing these resistors to well
over 100X the rise and fall times of the LM1203 can be increased for EMI considerations.
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