The MSK 1933 Series of High Speed, High Voltage Video Amplifiers are designed to drive the grid of today's high
performance CRTs. The MSK 1933 has user adjustable contrast and brightness levels and also comes with a blanking
function. The MSK 1933 can be directly connected to many video sources including RS170, RS343 and high speed
video D/A converters. The MSK 1933 is available in four versions for different applications. The MSK 1933-0 has no
internal high voltage resistor or inductor allowing the user to dissipate much of the power externally. The MSK 1933-
2, MSK 1933-4 and the MSK 1933-6 each have an internal resistor-inductor designed for optimum bandwidth. The
MSK 1933-6 has slightly lower bandwidth but can be operated from up to -120V. Each version of the MSK 1933 is
packaged in an isolated 22 pin insulated ceramic substrate that can be directly connected to a heat sink using
standard mounting techniques. The leads are available straight out, bent up or bent down.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
Helmet Mounted Displays
High Resolution RGB Displays
High Resolution Monochrome Displays
Automatic Test Equipment
Medical Monitors
CAE/CAD Station Monitors
Projection Displays
Beam Index Displays
1
2
3
4
5
6
7
8
PIN-OUT INFORMATION
Ground
Ground
Blank
V
EE
-Input
+Input
Ground
VGain
1
9
10
11
12
13
14
15
16
Voff
Vref
Ground
-V
HV
RES
-V
HV
RES
Ground
-V
HV
-V
HV
17
18
19
20
21
22
Output
N/C
Vcc
Vcc
Ground
Ground
Rev. A 8/00
ABSOLUTE MAXIMUM RATINGS
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-V
HV
ELECTRICAL SPECIFICATIONS
Parameter
STATIC
Quiescent Current
High Voltage Supply
INPUT
Input Bias Current 6
Blank Input Current
6
7
VCM=0V
VBLANK=0.4V
VBLANK=2.4V
VOFF=1V
VGAIN=5V
Normal Operation
Either Input F=DC
Either Input
VBLANK=2.4V VIN=0.3V
4
4
∆V=VHV-VOUT
∆VGAIN=5V
-
-
-
-
-
30
-
10K
-
-
-
25
-
6
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=3V Both Inputs
6
6
VGAIN=3V F=10KHz
VGAIN=3V F=10KHz
VIN=0.6V TR=TF<0.5nS
VGAIN =4V VOFF=1V VCM=0.5V
VOFF=1V VIN=2.0V VCM=0.5V
3
5.2
-3xRp
0
32
72
-85
-
-
-
-
-
±1
500
300
2
2
-
40
20K
2
-
-
30
0
5.5
Rp
3
42
110
-88
-1
3.5
-
-
-
±50
600
400
10
10
-
-
-
-
±2xRp
±10xRp
-
-
5.8
-
-
-
-
-
30
-
10K
-
-
-
25
380
5.2
±1
500
300
2
2
-
40
20K
2
-
-
30
400
5.5
Rp
3
42
110
-88
-1
3.0
-
-
-
±50
600
400
10
10
-
-
-
-
±2xRp
±10xRp
-
420
5.8
-
-
-
-
-
30
-
10K
-
-
-
25
190
5.2
±1
500
300
2
2
-
40
20K
2
-
-
30
200
5.5
Rp
3
21
55
-68
-1
2.5
-
-
-
±50
600
400
10
10
-
-
-
-
±2xRp
±10xRp
-
210
5.8
-
-
-
-
-
30
-
10K
-
-
-
25
380
5.2
±1
500
300
2
2
-
40
20K
2
-
-
30
400
5.5
Rp
3
42
120
-98
-1
6
-
-
-
±50
600
400
10
10
-
-
-
-
µA
µA
µA
µA
µA
nS
dB
Ω
pF
6 8
2 3
QOUT and QCAS
VCM=0V @ +20V
VCM=0V @ -10.5V
-
-
-30
-
75
-75
-90
10
100
-100
-95
13
-
-
-30
-
75
-75
-90
10
100
-100
-95
13
-
-
-30
-
75
-75
-70
10
100
-100
-75
13
-
-
-30
-
75
-75
-100
8
100
-100
-120
12
mA
mA
V
°C/W
Test Conditions
1
MSK1933-0
Min.
MSK1933-2
MSK1933-4
MSK1933-6
Units
Typ. Max. Min. Typ. Max. Min. Typ. Max. Min. Typ. Max.
Thermal Resistance to Case 3
Offset Adjust Input Current
Gain Adjust Input Current 7
Blank Input Pulse Width
Input Impedance 3
Input Capacitance 3
Blank Mode Input
Rejection
∆V
3
Gain Adjust Rejection
∆V
3
Internal Rp
OUTPUT
Reference Output Voltage
∆V
Blank Mode 4 5 6
∆V
Min Offset 5
∆V
Max Offset 5
Voltage Gain
6
6
6
3
4
3
Common Mode Rejection Ratio 3 VCM=±0.5V F=10Hz
±2xRp mV
±10xRp mV
-
420
5.8
3xRp
10
52
145
-
-5
8
±2
±2
±2
dB
Ω
V
mV
V
V
V/V
V
V
nS
%GS
%
%GS
Power Supply Rejection Ratio 3 +VCC and -VEE=Nom ±5%
3xRp -3xRp
6
52
138
-
-5
6.0
±2
±2
±2
0
32
72
-85
-
-
-
-
-
3xRp -3xRp
6
52
138
-
-5
5.0
±2
±2
±2
0
16
36
-65
-
-
-
-
-
3xRp -3xRp
6
26
68
-
-5
4.0
±2
±2
±2
0
32
72
-95
-
-
-
-
-
Output Voltage High
Output Voltage Low
Transistion Times 7
Linearity Error 3
Gain Linearity 3
Thermal Distortion
NOTES:
1
2
3
4
5
6
7
8
+V
CC
= +20V, -V
EE
= -10.5V, V
BLANK
= V
GAIN
= V
OFF
= ±V
IN
= 0V, C
L
=10pF, T
C
=25°C unless otherwise specified.
V
HV
=Typical Value for each dash number for all parameters.
This parameter is guaranteed by design but need not be tested. Typical parameters are representative of actual device performance but are for reference only.
R
P
=Internal R
P
except MSK 1933-0. External value = 400Ω unless otherwise specified for the MSK 1933-0.
∆V
is defined as the difference between -V
HV
and the output.
Parameter is 100% tested on production devices.
Parameter is sample tested in accordance with MSK industrial grade quality devices.
When the output is amplifying a video signal, the output current will be present at +V
CC
and -V
HV
since the output is referred to +V
CC
internally.
2
Rev. A 8/00
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V
CC
V
EE
V
IN
V
IC
V
GAIN
V
OFF
T
J
I
RP
T
C
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High Voltage Supply (1933-0)
(1933-2)
(1933-4)
(1933-6)
Positive Supply Voltage
Negative Supply Voltage
Differential Input Voltage
Common Mode Input Voltage
Gain Adjust Input Voltage
Offset Adjust Input Voltage
-95V
-95V
-75V
-120V
+22V
-12V
2V
±2V
-0.6 to +6V
-0.6 to +6V
V
BLANK
I
REF
T
ST
T
LD
-0.6 to +6V
Blank Input Voltage
5mA
Reference Output Current
Storage Temperature Range -40°C to +150°C
300°C
Lead Temperature Range
(10 Seconds)
150°C
Junction Temperature
290mA
Current Through Rp
Case Operating Temperature -25°C to +125°C
(All Devices)
APPLICATION NOTES
POWER SUPPLIES
The input stage of the MSK 1933 requires power supplies of
+20V 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 4.7µF) connected
as close to the amplifier's pins as possible. The MSK 1933 has
internal 0.01µF capacitors that also improve high frequency
performance. It is also recommended to put 0.1µF decoupling
capacitors on the +20V and -10.5V supplies as well. Since
the output stage is returned to +20V internally, all of the out-
put current will flow through this supply pin.
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 or external 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.
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 1933 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 25Ω resistor
to ground if input offset currents are to be minimized.
OUTPUT PROTECTION
The output pin of the MSK 1933 should be protected from
transients by connecting reversed biased ultra-low capacitance
diodes from the output pin to both -V
HV
and ground. The out-
put can also be protected from arc voltages by inserting a small
value (25-50Ω) resistor in series with the amplifier. This resis-
tor will reduce system bandwidth along with the load capaci-
tance, but a series inductor can reduce the problem substan-
tially.
V
GAIN
CONTROL INPUT
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 195V/V (MSK 1933-2). The V
GAIN
input should be connected
to the V
REF
pin through a 5KΩ pot to ground. For convenient
stable gain adjustment, a 0.1µF bypass capacitor should be con-
nected 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 tracking 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 1933 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 1932-2:
Given information
V
IN
=0.7V
V
GAIN
=1VDC
Rp=400Ω (internal)
V
HV
=-80VDC
V
HV
-V
OUT
=(0.7V)(1V)(400Ω)(0.09)
V
HV
-V
OUT
=25.2V Nominal
The expected video output would swing from approximately
-80V to -54.8V 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 variations.
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 applications 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 per-
formance.
Rev. A 8/00
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 any of
the MSK 1933 variants is determined by Vpp = (250mA) x
(Rp). The bandwidth of the amplifier largely depends on both
Rp and Lp.
Hybrid pins 12 and 13 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 capacitive and the layout should
minimize capacitive coupling to ground (ie: no ground plane
under Rp).
The MSK 1933 Series is conservatively specified with low
values for Lp which yield about 5% overshoot. Additional peak-
ing can be obtained by using a high self-resonant frequency
inductor in series with pins 12 & 13. Since this value of induc-
tance can be very dependent on circuit layout, it is best to
determine its value by experimentation. A good starting point
is typically 0.47µH for the MSK 1933-0 and 0.0047µH for the
remaining devices.
If external resistors or inductors are not used, be sure to
connect high frequency bypass capacitors directly from pins
12 and 13 to ground for the devices that contain an internal
Rp.
3
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 (5µA)(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 0.1µF 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. Total current through Rp should be
limited to less than 290mA when operating from power sup-
plies greater than 90V. The gain adjust alone can set the AC
current to 250mA (ie: 250mApp=100Vpp/400Ω). Typically,
most applications use about 10V 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 1933 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 1933 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. Use 4 to 6 inch/pounds for mounting the device
to the heat sink.
The power dissipation of the amplifier depends mainly on the
load requirements, bandwidth, pixel size, black level and the
value of Rp. The following table illustrates a few examples:
PERCENT OF SIGNAL
BLANK
100%
20%
100%
20%
BLACK
0%
40%
0%
40%
WHITE
0%
40%
0%
40%
OUTPUT
AVE. Pd
0W
13.3W
0W
8.4W
TOTAL
AVE. Pd
2.5W
15.7W
2.5W
10.6W
DEVICE
TYPE
1933-6
1933-6
1933-4
1933-4
-VHV
-120V
-120V
-70V
-70V
BLACK
LEVEL
-110V
-110V
-65V
-65V
WHITE
LEVEL
-20V
-20V
-15V
-15V
OUTPUT
VOLTAGE
0V
-90V
0V
-50V
This table does not include power dissipation due to output switching since this is dependent on individual load requirements. The input stage
power dissipation is typically 2.5 watts and is essentially independent of output levels.
RESOLUTION TABLE FOR TYPICAL CRT'S
Display
Resolution
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
Required System
Bandwidth
(F
-3dB
)
6MHz
20MHz
28MHz
41MHz
84MHz
95MHz
120MHz
180MHz
380MHz
1.23GHz
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
60nS
17nS
12.5nS
8.6nS
4.2nS
3.7nS
2.9nS
1.9nS
1nS
280pS
All data assumes retrace time equal to 30% of frame time and a 60Hz refresh rate.
4
Rev. A 8/00
TYPICAL CONNECTION CIRCUIT
The connection circuit shown above is for the MSK 1933-0 evaluation board. The Rp and Lp are external compo-
nents and must not be located near ground planes if possible. A high quality resistor such as Bradford Electronics P/
N FP10-400 is required for optimum response times. Use an inductor with a high self-resonant frequency that can
withstand the currents required for the application.
When using the other variants of the MSK 1933, place an additional bypass capacitor on pins 12 and 13 if series
(Rp and Lp) components are not utilized. The pin should connect to -V
HV
with a short low impedance path.
For additional applications information, please contact the factory. Evaluation amplifiers with test boards are
