ISO 9001 CERTIFIED BY DSCC
M.S.KENNEDY CORP.
FEATURES:
FAST SETTLING
HIGH VOLTAGE AMPLIFIER
612
(315) 701-6751
4707 Dey Road Liverpool, N.Y. 13088
Ultra Low Quiescent Current - ±13mA for High Voltage
140V Peak to Peak Output Voltage Swing
Slew Rate - 5000V/µS Typical
Settling Time to 0.05% - 1.5µS Max.
Input Offset Voltage Only - ±1mV Max.
Output Current - 250mA Peak
Adjustable VHV Power Supply Minimizes Power Dissipation
Compact Package Offers Superior Power Dissipation Capability
MIL-PRF-38534 QUALIFIED
DESCRIPTION:
The MSK 612 is a high voltage fast settling amplifier designed to provide large voltage swings at high slew rates
in wideband systems. The true inverting op-amp topology employed in the MSK 612 provides excellent D.C. specifi-
cations such as input offset voltage and input bias current. These attributes are important in amplifiers that will be
used in high gain configurations since the input error voltages will be multiplied by the system gain. The MSK 612
achieves impressive settling time specifications by employing a feed forward A.C. path through the amplifier, how-
ever, the device is internally configured in inverting mode to utilize this benefit. Internal compensation for gains of -
5V/V or greater keeps the MSK 612 stable in this range. The MSK 612 is packaged in a space efficient, hermetically
sealed, 12 pin power dual in line package that has a high thermal conductivity for efficient device cooling.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
Fast Settling High Voltage Amplifier
High Resolution CRT Monitor
Ultra High Performance Video Processing
CRT Beam Intensity Control
Varactor Tuned VCO Driver
Automatic Test Equipment
1
2
3
4
5
6
1
PIN-OUT INFORMATION
COMP
+VCC
GROUND
-VCC
-INPUT
NO CONNECTION
12
11
10
9
8
7
+VHV
+VSC
OUTPUT
CASE/GROUND
-VSC
-VHV
Rev. A 8/00
ABSOLUTE MAXIMUM RATINGS
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T
C
T
J
ELECTRICAL SPECIFICATIONS
Parameter
STATIC
V
IN
=0 @ +V
CC
Quiescent Current
V
IN
=0 @ -V
CC
V
IN
=0 @ +V
HV
V
IN
=0 @ -V
HV
Input Offset Voltage
V
IN
=0
1,2,3
1,2,3
1,2,3
1,2,3
1
2,3
1
2,3
V
IN
=0
±V
CC
±V
HV
f=1KHz
f=1KHz
V
0
=±50V
V
0
=±1.0V
V
0
=±50V
V
O
=±50V f=1KHz
A
V
=-10V/V V
O
=±50V
A
V
=-10V/V V
O
=±50V
A
V
=-10V/V V
O
=±50V
2,3
-
-
4
-
-
-
4
4
-
-
4
-
-
-
-
-
-
-
-
-
±12
±50
±50
5
80
90
-
-
-
1.0
12
12
12
±0.2
±1.0
50
100
±5
±15
±65
±58
12
100
100
100
400
750
3.5
30
20
20
±1.0
±2.5
200
250
±15
±18
±80
-
-
-
-
-
-
-
-
1.5
-
-
-
-
-
-
-
-
-
±12
±50
±50
4
80
2000
90
-
-
-
1.0
15
12
12
±1.0
±2.0
50
100
±5
±15
±65
±58
12
100
5000
100
100
400
750
4.0
32
22
22
±2.0
-
500
-
-
±18
±80
-
-
-
-
-
-
-
-
1.6
mA
mA
mA
mA
mV
mV
nA
nA
µV/°C
V
V
V
mA
MHz
MHz
V/µS
dB
nS
nS
µS
Test Conditions
1
Group A
Subgroup
MSK 612B
Min.
Typ.
Max.
Min.
MSK 612
Typ.
Max.
Units
Input Bias Current
Input Offset Voltage Drift
2
Power Supply Range
2
DYNAMIC CHARACTERISTICS
Output Voltage Swing
Peak Output Current
2
Full Power Output
2
Unity Gain Bandwidth
2
Slew Rate
Voltage Gain
2
Settling Time to 1%
2
Settling Time to 0.1%
2
Settling Time to 0.05%
±200 ±250
±200 ±250
2000 5000
NOTES:
1
2
3
4
5
Unless otherwise specified, ±V
CC
=±15V
DC
, ±V
HV
=±65V
DC
, C
L
=8pF (probe capacitance) and A
V
=10V/V.
This parameter is guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only.
Industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise specified.
Military grade devices ('B' suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroup 1,4
T
A
=T
C
=+25°C
Subgroup 2,5
T
A
=T
C
=+125°C
Subgroup 3,6
T
A
=T
C
=-55°C
2
Rev. A 8/00
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±V
HV
±V
IN
±V
CC
θ
JC
Supply Voltage
Input Voltage Range
Supply Voltage (Input Stage)
Thermal Resistance
(Output Devices)
±80V
DC
±V
CC
±18V
DC
30°C/W
T
ST
T
LD
Storage Temperature Range -65°C to +150°C
Lead Temperature Range
300°C
(10 Seconds)
Case Operating Temperature
MSK600
-40°C to +85°C
MSK600B
-55°C to +125°C
Junction Temperature
150°C
APPLICATION NOTES
FEED FORWARD TOPOLOGY
The MSK 612 employs a circuit topology known as "feed
forward". This inverting configuration allows the user to real-
ize the excellent D.C. input characteristics of a differential am-
plifier without losing system bandwidth. The incoming signal
is split at the input into its A.C. and D.C. component. The D.C.
component is allowed to run through the differential amplifier
where any common mode noise is rejected. The A.C. compo-
nent is "fed forward" to the output section through a very high
speed linear amplifier where it is mixed back together with the
D.C. component. The result is an amplifier with most of the
benefits of a differential amplifier without the loss in system
bandwidth.
VOLTAGE
GAIN
-10V/V
-20V/V
-50V/V
-R
IN
1KΩ
Ω
249Ω
Ω
100Ω
Ω
R
F
10KΩ
Ω
5KΩ
Ω
5KΩ
Ω
C
F
0.5-5pF
N/A
N/A
Table 1
INTERNAL COMPENSATION
Since the MSK 612 is a high voltage amplifier, it is com-
monly used in circuits employing large gains. Therefore, the
internal compensation was chosen for gains of -5V/V or greater.
In circuits running at gains of less than -5V/V, the user can
further compensate the device by adding compensation net-
works at the input or feedback node. Pin 1 (comp) should be
bypassed with a 1.0uF ceramic capacitor to +V
HV
for all appli-
cations.
CURRENT LIMIT
Figure 2 is a possible active short circuit protection scheme
for the MSK 612. The following formula may be used for set-
ting current limit:
Current Limit
≈
0.6V / Rsc
R
BASE
must be selected based on the value of ±V
HV
as fol-
lows:
R
BASE
= ((+V
HV
- (-V
HV
)) - 1.2V) / 4mA
This formula guarantees that Q2 and Q4 will always have suf-
ficient base current to be in operation. This circuit can be made
tolerant of high frequency output current spikes with the addi-
tion of C
SC
. The corresponding time constant would be:
T = (R
SC
) (C
SC
)
A common value for C
SC
is approximately 1000pF. If current
limit is unnecessary, short pin 7 to pin 8 and pin 11 to pin 12 as
shown in Figure 1.
HIGH VOLTAGE SUPPLIES
The positive and negative high voltage supplies on the MSK
612 can be adjusted to reduce power dissipation. The output
of the MSK 612 will typically swing to within 8V of either high
voltage power supply rail. Therefore, if the system in question
only needs the output of the amplifier to swing ±40V peak,
the power supply rails could be set to ±50V safely. For best
performance, the minimum value of ±V
HV
should be ±50V
DC
.
Unbalanced power supply rails are also allowed as long as one
or the other is not decreased to below 30V or above 80V. The
high voltage and low voltage power supplies should be decoupled
as shown in Figure 1.
TRANSITION TIMES
Transition time optimization of the MSK 612 follows the same
basic rules as most any other amplifier. Best transition times
will be realized with minumum load capacitance, minimum ex-
ternal feedback resistance and lowest circuit gain. Transition
times will degrade if the output is driven too close to either
supply rail. Feedback and input resistor values will affect tran-
sition time as well. See Figure 1 and Table 1 for recommended
component values.
Figure 1
3
Figure 2
Rev. A 8/00