4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
FEATURES:
Low Cost
High Voltage Operation:
Single Supply: +8V to +60V
Dual Supply: 4V to30V
High Output Current: 3 Amp Continuous
High Speed: 10V/S
Low Quiescent Current: 20 mA Typ.
Adjustable Current Limits
Thermal Shutdown
Monolithic Technology
Enable/Status Pin For Output Disable Control
MIL-PRF-38534 CERTIFIED
181
HIGH VOLTAGE/HIGH CURRENT
OPERATIONAL AMPLIFIER
ISO-9001 CERTIFIED BY DSCC
Servo Driver
Actuator Driver
Audio Amplifier
Power Supplies
1
2
3
4
+VIN
-VIN
ILIM
E/S
8
7
6
5
-Vcc
+Vcc
Output
N/C
M.S.KENNEDY CORP.
MSK181Z
MSK181
DESCRIPTION:
The MSK 181 is a high power monolithic operational amplifier ideal for use with a wide variety of loads. With operation from
either single or dual supplies, the MSK 181 offers excellent design flexibility. Power dissipation is kept to a minimum with a
quiescent current rating of only 20mA, while 3 Amps of continuous available output current makes the MSK 181 a very good low
cost choice for motor drive circuits and audio amplification. The MSK 181 is internally protected against current overloads and
overtemperature conditions. Current limit can also be user-selected through the use of a resistor/potentiometer or voltage out/
current out DAC. The MSK 181 is packaged in a hermetically sealed 8 pin power dip and the MSK 181Z is offered with bolt down
tabs for applications that require heat sinking.
EQUIVALENT SCHEMATIC
PIN-OUT INFORMATION
TYPICAL APPLICATIONS
PRELIMINARY Rev. C 8/01
1
Max.
30
20
20
-
10
-
500
50
-
-
-
-
-
-
-
-
-29
-
-
-
-
-
60V
5A
29.5V
+27V/-29V
Internal Protection
(See Application Note)
Total Supply Voltage
Output Current (within S.O.A.)
Input Voltage (Differential)
Input Voltage (Common Mode)
Junction Temperature
-65C to +150C
300C
-55C to +125C
-40C to +85C
1.8C/W
1
2
3
4
5
ABSOLUTE MAXIMUM RATINGS
T
ST
T
LD
T
C
R
TH
V
CC
I
OUT
V
IND
V
IN
T
J
Unless otherwise specified V
CC
= 30VDC and E/S pin is open.
Devices shall be capable of meeting the parameter, but need not to be tested. Typical parameters are for reference only.
Industrial grade and 'E' suffix devices shall be tested to subgroups 1 and 4 unless otherwise specified.
Military grade devices ('H' suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroup 1,4 T
A
=T
C
=+25C
Subgroup 2
T
A
=T
C
=+125C
Subgroup 3
T
A
=T
C
=-55C
Storage Temperature Range
Lead Temperature Range
(10 seconds)
Case Operating Temperature
(MSK181H/E)
(MSK181)
Thermal Resistance
Junction to Case
V
IN
=0V
V
IN
=0V
V
IN
=0V
V
IN
=OV
f=DC
f=DC
(-V
CC
)-
0.1
V
IN
(+V
CC)
-
3V
f=1KH
Z
I
OUT
=0.6A
I
OUT
=3.0A
DC=Continuous
V
ES
High- Output Enabled E/S Open or High
V
ES
Low- Output Disabled E/S Forced Low
A
V
=1 V
OUT=
50Vp-p R
L
=8
V
OUT
=25V R
L
=1K
A
V
=10 50V Step
Group A
Subgroup
-
1
2,3
-
1
-
1
1
-
-
1
-
4
4
4
4
4
-
-
-
4
-
STATIC
Supply Voltage Range
INPUT
Input Offset Voltage
Input Offset Voltage Drift
Input Bias Current
Input Offset Current
Input Impedance
Input Capacitance
Common Mode Rejection Ratio
Input Voltage Noise Density
OUTPUT
Output Current
Output Disable Time
Output Enable Time
TRANSFER CHARACTERISTICS
Open Loop Voltage Gain
Typ.
-
17
17
6
2
30
100
5
10
6
95
90
28
26
-
-
-
1
3
10
98
15
Min.
4
-
-
-
-
-
-
1
-
-
80
-
27
25.5
3
-27.5
-
-
-
-
90
-
Min.
4
-
-
-
-
-
-
-
-
-
75
-
26
24
3
-27.5
-
-
-
-
88
-
Max.
30
23
-
-
15
-
750
75
-
-
-
-
-
-
-
-
-29
-
-
-
-
-
Typ.
-
17
-
6
2
30
100
5
10
6
95
90
28
26
-
-
-
1
3
8
98
18
Units
V
mA
mA
mA
mV
V/C
n
A
n
A
pF
dB
nV/
H
Z
V
V
A
V
V
S
S
V/S
dB
S
MSK181H/E
MSK181
Parameter
Test Conditions
ELECTRICAL SPECIFICATIONS
1
NOTES:
Quiescent Current
2
PRELIMINARY Rev. C 8/01
Quiescent Current
V
IN
=0V
Shutdown Mode V
IN
=0V
7
7
Shutdown Input Mode
Output Voltage Swing
Slew Rate
Settling Time 0.1%
2
2
2
2
2
2
2
APPLICATION NOTES
POWER SUPPLIES:
The MSK 181 maximum total supply voltage is specified as
60V. However, dual and unbalanced power supply operation is
permissible as long as total supply voltage does not exceed
60V.
POWER SUPPLY BYPASSING:
Power supply terminals must be effectively decoupled with a
high and low frequency bypass circuit to avoid power supply
induced oscillation. An effective decoupling scheme consists
of a 0.1F ceramic capacitor in parallel with a 10F tantalum
capacitor for each power supply pin to ground. In addition, it is
recommended that a 0.01F capacitor be placed between Vcc
as close to the MSK 181 as possible.
COMPENSATION:
For normal operation output compensation is not typically
required. However, if the MSK 181 is intended to be driven into
current limit the user may find that an R/C network is required.
A snubber network from the output to ground will provide sta-
bility. If driving large capacitive or inductive loads, a snubber
network will also enhance stability. Typically 3
to 10
in se-
ries with 0.01F is acceptable.
CURRENT LIMIT:
The MSK 181 offers accurate, user-selectable current limit.
Unlike typical designs that use a power resistor in series with
the output to sense load, the MSK 181 senses the load indi-
rectly and therefore does not require a resistor to handle the full
output current. Current limit is selected by controlling the input
to the I
LIM
pin.
The easiest method is to use a resistor or potentiometer con-
nected between-Vcc and the I
LIM
pin. Use the following equa-
tion to select proper resistor value:
71,250
I
LIM
A low level control signal (0-330A) can also be used to con-
trol the current level digitally. If the pin is left open, the current
is programmed to OA, while connecting I
LIM
directly to -Vcc
sets the output current to it's maximum, typically 5A.
The MSK 181 is equipped with thermal protection circuitry
that protects the amplifier from damage caused by excessive
junction temperature. The output is disabled when the junction
temperature reaches approximately 160C. After the junction
temperature cools to approximately 140C, the output is again
enabled. The thermal protection may cycle on and off depend-
ing on the output load and signal conditions; this may have an
undesirable effect on the load.
It should be noted that even though this internal protection
circuitry does protect against overload conditions, it does not
take the place of proper heat sinking. For reliable operation,
junction temperature should be limited to 150C, maximum.
TYPICAL CONNECTION DIAGRAM
PRELIMINARY Rev. C 8/01
3
SAFE OPERATING AREA:
The safe operating area curve is a graphical representation of
the power handling capability of the amplifier under various
conditions. Power dissipation of the device is equal to the prod-
uct of the voltage across the output transistor times the output
current. As can be seen in the curve, safe operating current
decreases with an increase in temperature as well as an in-
crease in the voltage across the output transistor. Therefore,
for maximum amplifier performance it is important to keep case
temperature as low as possible and to keep Vcc as close to
the output rail as achievable.
THERMAL PROTECTION:
This pin actually has a dual function. First, when the pin is
forced low, the output stage is disabled. Second, it can be
monitored to determine if the device is in thermal shutdown.
These functions can be used on the same device with either
single or dual supplies. For normal operation, the E/S pin must
be left open or pulled at least 2.4 volts above the negative rail.
In noisy applications, a small value capacitor between the E/S
pin and -Vcc may be required.
ENABLE/STATUS PIN:
To disable the output, the user must pull the E/S pin low, no
greater than 0.8V above -Vcc. To once again enable the de-
vice, the E/S pin must be brought at least 2.4 volts above -Vcc
or disconnected. It should be noted that when the E/S pin is
high, the internal thermal shutdown is still active.
If the E/S pin is used to monitor thermal shutdown, during
normal operation the voltage on the E/S pin is typically 3.5V
above -Vcc. Once shutdown has occurred this voltage will drop
to approximately 350mV above -Vcc.
-13.75K
Rcc=
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