VCM=0V @ +15V
VCM=0V @ -10.5V
QOUT and QCAS
VCM=0V
VBLANK=0.4V
VBLANK=2.4V
VOFF=1V
VGAIN=5V
Normal Operation
VCM=0.5V F=10Hz
Either Input F=DC
Either Input
VBLANK=2.4V VIN=0.3V
V=VHV-VOUT
VGAIN=5V
+VCC and -VEE=Nom 5%
IOUT<2mA
V=VHV-VOUT VOFF=1V
VBLANK=2.4V VGAIN=5V
V=VHV-VOUT VOFF=0V VGAIN=3V
V=VHV-VOUT VOFF=5V
VIN=0.6V F=10KHz
VGAIN=4V Both Inputs
VGAIN=4V F=10KHz
VGAIN=4V F=10KHz
VIN=0.6V TR=TF<0.2nS (input)
VGAIN =4V VOFF=1V VCM=0.5V
VOFF=1V VIN=2.0V VCM=0.5V
Quiescent Current
Blank Input Current
V Blank Mode
Voltage Gain
STATIC
High Voltage Supply
Thermal Resistance to Case
INPUT
Input Bias Current
Offset Adjust Input Current
Gain Adjust Input Current
Blank Input Pulse Width
Common Mode Rejection Ratio
Input Impedance
Input Capacitance
Blank Mode Input
Rejection
V
Gain Adjust Rejection
V
Power Supply Rejection Ratio
Internal Rp
OUTPUT
Reference Output Voltage
V Min Offset
V Max Offset
Output Voltage High
Output Voltage Low
Transition Times
Linearity Error
Gain Linearity
Thermal Distortion
High Voltage Supply
Positive Supply Voltage
Negative Supply Voltage
Differential Input Voltage
Common Mode Input Voltage
Gain Adjust Input Voltage
Offset Adjust Input Voltage
-0.6 to +6V
5mA
-40C to +150C
300C
175C
290mA
-40C to +125C
ABSOLUTE MAXIMUM RATINGS
1
2
3
4
+V
CC
= +15V, -V
EE
= -10.5V, V
BLANK
= V
GAIN
= V
OFF
= V
IN
= 0V, C
L
=10pF, T
C
=25C unless otherwise specified.
This parameter is guaranteed by design but need not be tested. Typical parameters are representative of actual device performance but are for reference only.
V is defined as the difference between +V
HV
and the output.
Parameter is 100% tested on production devices.
+75V
+17V
-12V
2V
2V
-0.6 to +6V
-0.6 to +6V
+V
HV
V
CC
V
EE
V
IN
V
IC
V
GAIN
V
OFF
V
BLANK
I
REF
T
ST
T
LD
T
J
I
RP
T
C
ELECTRICAL SPECIFICATIONS
NOTES:
Rev. D 4/02
2
Blank Input Voltage
Reference Output Current
Storage Temperature Range
Lead Temperature Range
(10 Seconds)
Junction Temperature
Current Through Rp
Case Operating Temperature
Units
mA
mA
V
C/W
A
A
A
A
A
nS
dB
pF
mV
dB
V
V
V
V
V
nS
%GS
%
%GS
Min.
-
-
30
-
-
-
-
-
-
30
-
10K
-
-
25
140
5.2
0
11
65
-
-
-
-
-
Typ.
75
-75
70
24
1
500
300
2
2
-
40
20K
2
-
30
150
5.5
2
16
68
10
1.5
-
-
-
Max.
100
-100
75
26
50
600
400
10
10
-
-
-
-
-
160
5.8
6
21
-
20
-
2
2
2
MSK1922
Test Conditions
1
2
2
2
2
2
2
2
2
2
2
2
3
2
3
4
3
3
4
4
2
4
2
3
4
2
3
2
2
2
Parameter
-
-
2xRp
10xRp
-3xRp
Rp
3xRp
40
54
64
mV
mV
V/V
APPLICATION NOTES
POWER SUPPLIES
The input stage of the MSK 1922 requires power supplies of
+15V and -10.5V for optimum operation. The negative power
supply can be increased to -12V if -10.5V is not available, but
additional power dissipation will cause the internal temperature
to rise. Both low voltage power supplies should be effectively
decoupled with tantalum capacitors (at least 4.7F) connected
as close to the amplifier's pins as possible. The MSK 1922 has
internal 0.01F capacitors that also improve high frequency
performance. In any case, it is also recommended to put 0.1F
decoupling capacitors on the +15V and -10.5V supplies as
well.
The high voltage power supply (+V
HV
) is connected to the
amplifier's output stage and must be kept as stable as possible.
The internal Rp is connected to +V
HV
and as such, the amplifier's
DC output is directly related to the high voltage value. The
+V
HV
pins of the hybrid should be decoupled to ground with as
large a capacitor as possible to improve output stability.
SUPPLY SEQUENCING
The power supply sequence is V
HV
, V
CC
, V
EE
followed by the
other DC control inputs. If power supply sequencing is not
possible, the time difference between each supply should be
less than five milliseconds. If the DC control signals are being
generated from a low impedance source other than the V
REF
output, reverse biased diodes should be connected from each
input (V
GAIN
, V
OFF
) to the V
CC
pin. This will protect the inputs
until V
CC
is turned on.
VIDEO OUTPUT
When power is first applied and V
IN
=V
GAIN
=V
OFF
=0V, the
output will be practically at the +V
HV
rail voltage. The output
voltage is a function of the value of Rp and also the V
GAIN
and
V
OFF
DC inputs. The maximum output voltage swing for the
MSK 1922 is determined by (Rp). The bandwidth of the ampli-
fier largely depends on both Rp and Lp.
Hybrid pins 16 and 17 are directly connected to Rp. Addi-
tional external resistance can be added to reduce power dissi-
pation, but slower transition times will result. If an additional
resistor is used, it must be low capacitance and the layout
should minimize capacitive coupling to ground (ie: no ground
plane under Rp).
The MSK 1922 is specified with no external Lp which yields
about 10% overshoot. Additional peaking can be obtained by
using a high self-resonant frequency inductor in series with pins
16 & 17. Since this value of inductance can be very dependent
on circuit layout, it is best to determine its value by experimen-
tation. A good starting point is typically 0.0047H.
If external resistors or inductors are not used, be sure to
connect high frequency bypass capacitors directly from pins
16 and 17 to ground.
Rev. D 4/02
3
The V
GAIN
control (contrast) input is designed to allow the
user to vary the video gain. By simply applying a DC voltage
from 0V to V
REF
, the video gain can be linearly adjusted from 0
to 73V/V. The V
GAIN
input should be connected to the V
REF
pin
through a 5K
pot to ground. For convenient stable gain adjust-
ment, a 0.1F bypass capacitor should be connected near the
V
GAIN
input pin to prevent output instability due to noisy sources.
Digital gain control can be accomplished by connecting a D/A
converter to the V
GAIN
pin. However, some temperature track-
ing performance may be lost when using an external DC voltage
source other than V
REF
for gain adjustment. The bandwidth of
the V
GAIN
input is approximately 1MHz.
The overall video output of the MSK 1922 can be character-
ized using the following expression:
Vpp=V
HV
-V
OUT
V
HV
-V
OUT
=(V
IN
)(V
GAIN
)(Rp)(0.09)
(or)
Voltage Gain=V
OUT
/V
IN
=(V
GAIN
)(Rp)(0.09)
Here is a sample calculation for the MSK 1922:
Given information
V
IN
=0.7V
V
GAIN
=1VDC
Rp=150
(internal)
V
HV
=70VDC
V
HV
-V
OUT
=(0.7V)(1V)(150
)(0.09)
V
HV
-V
OUT
=9.5V Nominal
The expected video output would swing from approximately
+70V to +60.5 V assuming that V
OFF
=0V. This calculation
should be used as a nominal result because the overall gain may
vary as much as 20% due to internal high speed device varia-
tions. Changing ambient conditions can also effect the video
gain of the amplifier by as much as 150 PPM/C. It is wise to
connect all video amplifiers to a common heat sink to maximize
thermal tracking when multiple amplifiers are used in applica-
tions such as RGB systems. Additionally, only one of the V
REF
outputs should be shared by all three amplifiers. This voltage
should be buffered with a suitable low drift op-amp for best
tracking performance.
V
GAIN
CONTROL INPUT
OUTPUT PROTECTION
The output pin of the MSK 1922 should be protected from
transients by connecting reversed biased ultra-low capacitance
diodes from the output pin to both +V
HV
and ground. The
output can also be protected from arc voltages by inserting a
small value (25-50
) resistor in series with the amplifier. This
resistor will reduce system bandwidth along with the load ca-
pacitance, but a series inductor can reduce the problem sub-
stantially.
VIDEO INPUTS
The video input signals should be kept below 2V
MAX
total,
including both common mode offset and signal levels. The
input structure of the MSK 1922 was designed for 0.714Vpp
RS343 signals. If either input is not used it should be con-
nected directly to the analog ground or through a 25
resistor
to ground if input offset currents are to be minimized.
APPLICATION NOTES CON'T
V
OFF
CONTROL INPUT
The brightness (output offset) can be linearly adjusted by
applying a 0 to V
REF
DC voltage to the V
OFF
input pin. The
output quiescent voltage range is from approximately (5A)(Rp)
to (100mA)(Rp) from +V
HV
. This control voltage is normally
generated by connecting the V
OFF
control pin to a 5K potenti-
ometer between V
REF
and ground. The V
OFF
input pin should
be bypassed with a 0.1F capacitor to ground placed as close
as possible to the hybrid. This DC voltage can be any stable
system source. The bandwidth of the V
OFF
pin is approximately
1MHz.
Keep hybrid power dissipation in mind when adjusting the
output quiescent voltage. Practically all of the voltage is seen
across Rp! This power must be taken into account when high
Rp currents are used. If the quiescent level is set too close to
+V
HV
, the power dissipation will be minimal but the rise time
will suffer slightly. If the quiescent level is set too far from
+V
HV
, the power dissipation will increase dramatically and the
output fall time will be limited. The output black level is obvi-
ously dependent on system requirements but a little experi-
mentation will strike the optimum balance between power dis-
sipation and bandwidth. The gain adjust alone can set the AC
current to 333mA (ie: 333mApp=50Vpp/150
). Typically,
most applications use about 5V from +V
HV
for a black level.
BLANK INPUT
The video input can be electrically disconnected from the
ampliifer by applying a TTL high input to the blank pin. When
this occurs, the output will be set to approximately +V
HV
. The
V
GAIN
and V
OFF
control pins have little or no effect on the out-
put when it is in blank mode.
When the TTL compatible blank input is not used, the pin
must be connected to ground to enable the amplifier. The blank
input will float high when left unconnected which will disable
the video.
V
REF
OUTPUT
The MSK 1922 has an on board buffered DC zener reference
output. The V
REF
output is nominally 5.5V DC and has full
temperature test limits of 5.2V to 5.8V DC. This output is
provided for gain and offset adjustment and can source up to
4mA of current.
THERMAL MANAGEMENT
The MSK 1922 package has mounting holes that allow the
user to connect the amplifier to a heat sink or chassis. Since
the package is electrically isolated from the internal circuitry,
mounting insulators are not required or desired for best thermal
performance.
The power dissipation of the amplifier depends mainly on the
load requirements, bandwidth, pixel size, black level and the
value of Rp.
320 x 200
640 x 350
640 x 480
800 x 560
1024 x 900
1024 x 1024
1280 x 1024
1664 x 1200
2048 x 2048
4096 x 3300
Maximun
Pixel
Time
182nS
52nS
38nS
26nS
12.6nS
11nS
8.9nS
5.8nS
2.8nS
860pS
Minimum Pixel
Clock
Frequency
5MHz
19MHz
26MHz
38MHz
80MHz
90MHz
112MHz
170MHz
360MHz
1.2GHz
Required Rise Time
at CRT
Cathode
60nS
17nS
12.5nS
8.6nS
4.2nS
3.7nS
2.9nS
1.9nS
1nS
280pS
Required System
Bandwidth
(F
-3dB
)
6MHz
20MHz
28MHz
41MHz
84MHz
95MHz
120MHz
180MHz
380MHz
1.23GHz
RESOLUTION TABLE FOR TYPICAL CRT'S
All data assumes retrace time equal to 30% of frame time and a 60Hz refresh rate.
Display
Resolution
Rev. D 4/02
4
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