ISO 9001 CERTIFIED BY DSCC
M.S.KENNEDY CORP.
1461
HIGH SPEED/VOLTAGE
OP AMP
4707 Dey Road Liverpool, N.Y. 13088
(315) 701-6751
MIL-PRF-38534 CERTIFIED
FEATURES:
Extremely Fast - 500v/µS
Wide Supply Range ±15V to ±45V
VMOS Output, No S.O.A. Restrictions
Large Gain-Bandwidth Product
FET Input
Electrically Isolated Case
800mA Typical Output Current
DESCRIPTION:
The MSK 1461 is a state of the art high speed FET input operational amplifier. The distinguishing characteristic
of the MSK 1461 is its unique VMOS output stage which completely eliminates the safe operating area restrictions
associated with secondary breakdown of bipolar transistor output stage op-amps. Freedom from secondary breakdown allows the 1461 to handle large output currents at any voltage level limited only by transistor junction temperature. 115 dB of open loop gain gives the 1461 high closed loop gain accuracy and the typical ±1.0mV of input offset
voltage will fit well in any error budget. A 500 V/µS slew rate and 1200 MHz gain bandwidth product make the 1461
an outstanding high-speed op-amp. A single external capacitor is used for compensation and output current limiting
is user programmable through the selection of two external resistors.
EQUIVALENT SCHEMATIC
PIN-OUT INFORMATION
TYPICAL APPLICATIONS
Video Yoke Drivers
Video Distribution Amplifiers
High Accuracy Audio Amplification
High Speed ATE Pin Drivers
1
2
3
4
5
6
7
1
Inverting Input
Non-Inverting Input
No Connection
No Connection
Negative Power Supply
Negative Current Limit
No Connection
8
9
10
11
12
13
14
Output
Positive Current Limit
Positive Power Supply
Compensation
Compensation
Offset Adjust
Offset Adjust
Rev. B 8/00
ABSOLUTE MAXIMUM RATINGS
±VCC
IOUT
VIN
RTH
Supply Voltage
Output Current
Differential Input Voltage
Thermal Resistance
Junction to Case
(Output Devices Only)
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TST Storage Temperature Range
TLD Lead Temperature Range
(10 Seconds)
TC Case Operating Temperature
(MSK 1461B)
(MSK 1461)
TJ Junction Temperature
±45V
800mA
±25V
12°C/W
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-65°C to +150°C
300°C
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-55°C to +125°C
-40°C to 85°C
+175°C
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ELECTRICAL SPECIFICATIONS
MSK 1461B
MSK 1461
Group A
Subgroup
Min.
Typ.
Max.
Min.
Typ.
Max.
-
±15
-
±45
±15
-
±45
V
1
-
±19
±25
-
±19
±28
mA
2,3
-
±21
±35
-
-
-
mA
Junction to Case
-
-
11
12
-
11
15
°C/W
VIN=0V AV=-10V/V
1
-
±1.0 ±5.0
-
±1.0 ±8.0
Bal. Pins=N/C
2,3
-
±6.0
±50
-
±10
-
RPOT=10KΩ to +VCC
-
-
±8.0
-
-
±8.0
-
VCM=0V
1
-
±10 ±300
-
±10 ±300
Either Input
2,3
-
±10 ±100
-
-
-
nA
-
-
±5.0
-
-
±5.0
-
pA
-
-
±5.0
-
-
-
-
-
3x10 12
-
-
-
±22
±24
-
F=10KHz VCM=±22V
4
90
100
RL=50Ω AV=-5V/V
4
±27
RL=1KΩ
4
±30
RL=33Ω AV=-5V/V TJ<175°C
4
±600 ±800
0.1% 10V step
4
-
400
800
-
VOUT=±10V RL=1KΩ AV=-5V/V
4
200
500
-
Open Loop Voltage Gain 3
RL=1KΩ F=100Hz
4
90
106
Gain Bandwidth Product 3
F=100KHz
4
800
1200
Test Conditions
Parameter
Units
STATIC
Supply Voltage Range 3
Quiescent Current
Thermal Resistance
VIN=0V
3
INPUT
Input Offset Voltage
Input Offset Voltage Drift
Input Offset Adjust 3
Input Bias Current
Input Offset Current 3
VCM=0V
Input Impedance 3
F=DC
Common Mode Range 3
Common Mode Rejection Ratio 3
mV
µV/°C
V
pA
-
nA
3x10 12
-
Ω
±22
±24
-
V
-
90
100
-
dB
±31
-
±27
±31
-
V
±33
-
±30
±33
-
V
-
±600 ±800
-
mA
400
800
nS
200
500
-
V/µS
-
90
106
-
dB
-
800
1200
-
MHz
OUTPUT
Output Voltage Swing
Output Current, Peak
Settling Time 2 3
TRANSFER CHARACTERISTICS
Slew Rate
NOTES:
1
2
3
4
5
6
7
RSC=0Ω and ±VCC=36VDC unless otherwise specified.
AV=-1, 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 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.
Subgroups 5 and 6 testing available upon request.
Subgroup 1,4 TC=+25°C
Subgroup 2,5 TJ=+125°C
Subgroup 3,6 TA=-55°C
2
Rev. B 8/00
APPLICATION NOTES
HEAT SINKING
To select the correct heat sink for your application,
refer to the thermal model and governing equation below.
Thermal Model:
CURRENT LIMIT
The output current of the MSK 1461 is internally limited to approximately ±750mA by two 0.8Ω internal current limit resistors. Additional current limit can be achieved
through the use of two external current limit resistors.
One resistor (+RSC) limits the positive output current and
the other (-RSC) limits the negative output current. The
value of the current limit resistors can be determined as
follows:
±RSC = [(0.65V/±ILIM) - 0.8Ω]
Since the 0.65V term is obtained from the base to
emitter voltage drop of a bipolar transistor, the equation
only holds true for +25°C operation. As case temperature increases, the 0.65V term will decrease making the
actual current limit set point decrease slightly.
Governing Equation:
The following schematic illustrates how to connect
each current limit resistor:
TJ=PD x (RθJC + RθCS + RθSA) + TA
Where
TJ = Junction Temperature
PD = Total Power Dissipation
RθJC = Junction to Case Thermal Resistance
RθCS = Case to Heat Sink Thermal Resistance
RθSA = Heat Sink to Ambient Thermal Resistance
TC = Case Temperature
TA = Ambient Temperature
TS = Sink Temperature
Example:
In our example the amplifier application requires the
output to drive a 20 volt peak sine wave across a 400Ω
load for 50mA of peak output current. For a worst case
analysis we will treat the 50mA peak output current as a
D.C. output current. The power supplies shall be set to
±40VDC.
INPUT OFFSET ADJUST CONNECTION
IN
POWER SUPPLY BYPASSING
Both the negative and the positive power supplies 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 0.1µF ceramic capacitor in parallel with a 4.7µF tantalum capacitor from each power supply pin to ground.
SAFE OPERATING AREA
Any designer who has worked with power operational
amplifiers is familiar with Safe Operating Area (S.O.A.)
curves. S.O.A. curves are a graphical representation of
the following three power limiting factors of any bipolar
transistor output op-amp.
1. Wire Bond Current Carrying Capability
2. Transistor Junction Temperature
3. Secondary Breakdown Limitations
Since the MSK 1461 utilizes a MOSFET output, there
are no secondary breakdown limitations and therefore no
need for S.O.A. curves. The only limitation on output
power is the junction temperature of the output drive transistors.
Whenever possible, junction temperature should be
kept below 150°C to ensure high reliability. See "Heat
The heat sink in this example must have a thermal
Sinking" for more information involving junction temperaresistance of no more than 2.85°C/W to maintain a juncture calculations.
tion temperature of no more than +125°C.
Rev. B 8/00
3
1.) Find Driver Power Dissipation
PD = [(quiescent current) x (+VS - (-VS))] +
[(+VS-VO) x IOUT]
= [(50mA) x (80V)] + [(20V) x (0.05A)]
= 4W + 1.0W
= 5Watts
2.) For conservative design, set TJ=+125°C.
3.) For this example, worst case TA=+50°C
4.) RθJC = 12°C/W from MSK 1461B Data Sheet
5.) RθCS = 0.15°C/W for most thermal greases
6.) Rearrange governing equation to solve for RθSA
RθSA = ((TJ - TA)/PD) - (RθJC) - (RθCS)
= ((125°C - 50°C) / 5W) - (12°C/W) - (.15°C/W)
≅ 2.85°C/W
TYPICAL PERFORMANCE CURVES
4
Rev. B 8/00
MECHANICAL SPECIFICATIONS
ESD Triangle Indicates Pin 1.
NOTE: ALL DIMENSIONS ARE ±0.010 UNLESS OTHERWISE LABELED.
ORDERING INFORMATION
Part
Number
Screening Level
MSK1461
Industrial
MSK1461B
Military-Mil-PRF-38534
M.S. Kennedy Corp.
4707 Dey Road, Liverpool, New York 13088
Phone (315) 701-6751
FAX (315) 701-6752
www.mskenndy.com
The information contained herein is believed to be accurate at the time of printing. MSK reserves the right to make
changes to its products or specifications without notice, however, and assumes no liability for the use of its products.
5
Rev. B 8/00