4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
FEATURES:
MIL-PRF-38534 QUALIFIED
ISO-9001 CERTIFIED BY DSCC
EQUIVALENT SCHEMATIC
M.S.KENNEDY CORP.
The MSK 164 is an ultra high voltage monolithic MOSFET operational amplifier ideally suited for electrostatic
transducer and electrostatic deflection applications. With a total supply voltage rating of 350 volts and 60mA of
available output current, the MSK 164 is also an excellent low cost choice for high voltage piezo drive circuits. The
MOSFET output frees the MSK 164 from secondary breakdown limitations and power dissipation is kept to a mini-
mum with a quiescent current rating of only 2mA. The MSK 164 has user adjustable compensation pins and is
packaged in a 14 pin power dip with bolt down tabs.
DESCRIPTION:
Monolithic MOS Technology
External Compensation Capability
High Voltage Operation : 350V
Low Quiescent Current : 2mA Max.
High Output Current : 60mA Min.
No Secondary Breakdown
High Speed : 40V/S Typ.
Low Cost
14
13
12
11
10
9
8
PIN-OUT INFORMATION
1
2
3
4
5
6
7
TYPICAL APPLICATIONS
Piezo Electric Positioning
Electrostatic Deflection
Computer to Vacuum Tube Interface
Ultra High Voltage Op-Amp Applications
NC
NC
-Vcc
+Vcc
Output Drive
Comp 1
Comp 2
Non-Inverting Input
Inverting Input
N/C
N/C
N/C
N/C
Current Sense
ULTRA HIGH VOLTAGE
OPERATIONAL AMPLIFIER
164
MSK164
Rev. B 6/02
1
350V
60mA
120mA
16V
Vcc
150C
Storage Temperature
Lead Temperature
Case Operating Temperature
(MSK164B/E)
(MSK164)
Thermal Resistance (DC)
Junction to Case
-65C to +150C
300C
-55C to +125C
-40C to +85C
12C/W
Total Supply Voltage
Output Current (within S.O.A.)
Output Current Peak
Input Voltage (Differential)
Input Voltage (Common Mode)
Junction Temperature
1
2
3
4
5
6
7
8
9
ABSOLUTE MAXIMUM RATINGS
T
ST
T
LD
T
C
R
TH
V
CC
I
OUT
I
OUTP
V
IND
V
IN
T
J
Unless otherwise noted C
C
=18pF, R
C
=2.2K
, V
CC
= 150VDC.
Derate maximum supply voltage 0.5V/C below T
C
=+25C. No derating is needed above T
C
=25C.
A
V
=-10V/V measured in false summing junction circuit.
Devices shall be capable of meeting the parameter, but need not be tested. Typical parameters are for reference only.
Industrial grade and "E" suffix devices shall be tested to subgroups 1 and 4 unless otherwise requested.
Military grade devices ('B' suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroup 5 and 6 testing available upon request.
Subgroup 1,4 T
C
=+25C
Subgroup 2,5 T
C
=+125C
Subgroup 3,6 T
A
=-55C
Electrical specifications are derated for power supply voltages less than 50VDC.
V
IN
=0V
V
IN
=0V
V
IN
=0V
V
IN
=0V
V
CM
=0V
(DC)
V
CM
=90VDC
1Hz
f
10Hz
I
OUT
=40mA Peak
V
OUT
=MAX
C
C
=10pF V
OUT
=280V
PP
No Load R
CL
=0
C
C
=10pF 10V Step
A
V
=+1V/V
C
C
=Open
F=15Hz R
L
=5K
Group A
Subgroup
-
1
2
3
1
2,3
1
1
2,3
-
-
-
-
4
4
-
-
-
-
4
4
STATIC
Supply Voltage Range
Quiescent Current
INPUT
Offset Voltage
Offset Voltage Drift
Offset Voltage vs Vcc
Input Bias Current
Input Impedance
Input Capacitance
Common Mode Rejection
Noise
OUTPUT
Output Voltage Swing
Output Current
Power Bandwidth
Resistance
Settling Time to 0.1%
Capacitive Load
TRANSFER CHARACTERISTICS
Slew Rate
Open Loop Voltage Gain
Typ.
150
1.4
2.0
1.0
15
40
20
5
-
10
5
94
50
141
120
26
150
12
-
40
106
Min.
50
-
-
-
-
-
-
-
-
-
-
84
-
138
60
-
-
-
10
20
94
Min.
50
-
-
-
-
-
-
-
-
-
-
84
-
138
60
-
-
-
10
20
94
Max.
175
2.0
-
-
30
-
32
100
-
-
-
-
-
-
-
-
-
-
-
-
-
Typ.
150
1.4
-
-
15
40
20
5
-
10
5
94
50
141
120
26
150
12
-
40
106
Units
V
mA
mA
mA
mV
V/C
V/V
pA
nA
pF
dB
V
RMS
V
mA
KHz
S
nF
V/S
dB
MSK164B/E
MSK164
2
Parameter
Max.
175
2.0
3.0
2.1
30
65
32
50
50
-
-
-
-
-
-
-
-
-
-
-
-
4
Test Conditions
ELECTRICAL SPECIFICATIONS
4
4
1
4
4
3 4
NOTES:
4
4
4
2
9
4
4
11
11
Rev. B 6/02
2
APPLICATION NOTES
R
CL
=3/I
LIM
V
R
=I
O
R
CL
*
Current limit resistor value can be calculated as follows:
It is recommended that the user set up the value of current limit
as close as possible to the maximum expected output current
to protect the amplifier. The minumum value of current limit
resistance is 33 ohms. The maximum practical value is 500
ohms. Current limit will vary with case temperature. Refer to
the typical performance graphs as a guide. Since load current
passes through the current limit resistor, a loss in output volt-
age swing will occur. The following formula approximates out-
put voltage swing reduction:
When the device is in current limit, there will be spurious oscil-
lations present on the negative half cycle. The frequency of
the oscillation is application dependent and can not be pre-
dicted. Oscillation will cease when the device comes out of
current limit.
CURRENT LIMIT
INPUT PROTECTION
Input protection circuitry within the MSK 164 will clip differ-
ential input voltages greater than 16 volts. The inputs are also
protected against common mode voltages up to the supply rails
as well as static discharge. There are 300 ohm current limiting
resistors in series with each input. These resistors may be-
come damaged in the event the input overload is capable of
driving currents above 1mA. If severe overload conditions are
expected, external input current limiting resistors are recom-
mended.
OUTPUT SNUBBER NETWORK
A 100 ohm resistor and a 330pF capacitor connected in se-
ries from the output of the amplifier to ground is recommended
for applications where load capacitance is less than 330pF.
For larger values of load capacitance, the output snubber net-
work may be omitted. If loop stability becomes a problem due
to excessively high load capacitance, a 100 ohm resistor may
be added between the output of the amplifier (the junction of
R
CL
and pin 8) and the load. A small tradeoff with bandwidth
must be made in this configuration. The graph below illus-
trates the effect of capacitive load on open loop gain. Note
that the snubber capacitor must have a voltage rating greater
than or equal to the total rail to rail power supply voltage.
SAFE OPERATING AREA (SOA)
The MOSFET output stage of this power operational ampli-
fier has two distinct limitations:
1. The current handling capability of the die metallization.
2. The junction temperature of the output MOSFET's.
NOTE: The output stage is protected against transient flyback.
However, for protection against sustained, high energy flyback,
external fast-recovery reverse biased diodes should be connected
from the output to ground.
The MSK 164 has sufficient phase margin when compen-
sated for unity gain to be stable with capacitive loads of at
least 10nF. However, it is recommended that the parallel sum
of the input and feedback resistor be 1000 ohms or less for
closed loop gains of ten or less to minimize phase shift caused
by the R-C network formed by the input resistor, feedback re-
sistor and input capacitance. The user can tailor the perfor-
mance of the MSK 164 to their application using the external
compensation pins. The graphs of small signal gain and phase
as well as the graphs of slew rate and power response demon-
strate the effect of various forms of compensation. The com-
pensation capacitor must be rated at 350 volts working voltage
if maximum power supply voltages are used. The compensa-
tion resistor and capacitor lead lengths must be kept as short
as possible to minimize spurious oscillations. A high quality
NPO capacitor is recommended for the compensation capaci-
tor.
STABILITY
External compensation is only necessary at gains of 30V/V
or less. For larger gains, the compensation resistor and capaci-
tor may be omitted. An effective method of checking amplifier
stability is to apply the worst case capacitive load to the output
of the amplifier and drive a small signal square wave across it.
If overshoot is less than 25%, the system will generally be
stable.
EXTERNAL COMPENSATION
Rev. B 6/02
3
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