HIGH VOLTAGE POWER OPERATIONAL AMPLIFIERS
PA89 • PA89A
M I C R O T E C H N O L O G Y
HTTP://WWW.APEXMICROTECH.COM
(800) 546-APEX
(800) 546-2739
FEATURES
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•
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1140V P-P SIGNAL OUTPUT
WIDE SUPPLY RANGE —
±75V
to
±600V
PROGRAMMABLE CURRENT LIMIT
75 mA CONTINUOUS OUTPUT CURRENT
HERMETIC SEALED PACKAGE
INPUT PROTECTION
PATENTED
APPLICATIONS
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•
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PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC DEFLECTION
SEMICONDUCTOR TESTING
TYPICAL APPLICATION
Ultra-high voltage capability combined with the bridge am-
plifier configuration makes it possible to develop +/–1000 volt
peak swings across a piezo element. A high gain of –50 for A1
insures stability with the capacitive load, while “noise-gain”
compensation Rn and Cn on A2 insure the stability of A2 by
operating in a noise gain of 50.
50R
50R
50R
+600V
R
V
IN
A1
PA89
PIEZO
TRANSDUCER
–600V
–600V
A2
PA89
+600V
R
DESCRIPTION
The PA89 is an ultra high voltage, MOSFET operational
amplifier designed for output currents up to 75 mA. Output
voltages can swing over 1000V p-p. The safe operating area
(SOA) has no second breakdown limitations and can be
observed with all types of loads by choosing an appropriate
current limiting resistor. High accuracy is achieved with a
cascode input circuit configuration and 120dB open loop gain.
All internal biasing is referenced to a bootstrapped zener-
MOSFET current source, giving the PA89 a wide supply range
and excellent supply rejection. The MOSFET output stage is
biased for class A/B linear operation. External compensation
provides user flexibility. The PA89 is 100% gross leak tested
to military standards for long term reliability.
This hybrid integrated circuit utilizes a beryllia (BeO) sub-
strate, thick film resistors, ceramic capacitors and semicon-
ductor chips to maximize reliability, minimize size and give top
performance. Ultrasonically bonded aluminum wires provide
reliable interconnections at all operating temperatures. The
MO-127 High Voltage, Power Dip™ package is hermetically
sealed and electrically isolated.
Cn
SINGLE AXIS MICRO-POSITIONING
EXTERNAL CONNECTIONS*
–IN
+IN
N/C
1
2
3
4
5
12
11
TOP
VIEW
10
9
8
7
RESERVED
RESERVED
C
C
COMP
R
C
+V
S
C
L
R
CL
=
.7
I
LIM
COMP
SIMPLIFIED SCHEMATIC
D1
Q5
Q1
Q2
D57
COMP
9 10
–IN
1
Q22
Q25A
Q23
Q25B
+IN
2
Q19
Q20
Q26
C
L
7
8
+V
S
N/C
–V
S
OUT
6
Q29
Q36
6
OUT
R
CL
PHASE COMPENSATION
Gain
1
10
15
100
C
C
470pF
68pF
33pF
15pF
R
C
470Ω
220Ω
220Ω
220Ω
D30
D35
Q45
D34
D31
Q44
D5
Q42
–V
S
5
Note: C
C
must be rated for full supply voltage –Vs to +Vs.
See details under “EXTERNAL COMPONENTS”.
APEX MICROTECHNOLOGY CORPORATION
• TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
PA89 • PA89A
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
to –V
S
OUTPUT CURRENT, within SOA
POWER DISSIPATION, internal at T
C
= 25°C
INPUT VOLTAGE, differential
INPUT VOLTAGE, common mode
TEMPERATURE, pin solder - 10s max
TEMPERATURE, junction
2
TEMPERATURE, storage
OPERATING TEMPERATURE RANGE, case
PA89
TEST CONDITIONS
1
MIN
TYP
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
1200V
100mA
40W
±25V
±V
S
25V
300°C
150°C
–65 to 125°C
–55 to 125°C
±
PA89A
MAX
MIN
TYP
MAX
UNITS
SPECIFICATIONS
PARAMETER
INPUT
OFFSET VOLTAGE, initial
OFFSET VOLTAGE, vs. temperature
OFFSET VOLTAGE, vs. supply
OFFSET VOLTAGE, vs. time
BIAS CURRENT, initial
3
BIAS CURRENT,vs. supply
OFFSET CURRENT, initial
3
INPUT IMPEDANCE, DC
INPUT CAPACITANCE
COMMON MODE VOLTAGE RANGE
4
COMMON MODE REJECTION, DC
INPUT NOISE
GAIN
OPEN LOOP GAIN at 10Hz
GAIN BANDWIDTH PRODUCT
POWER BANDWIDTH
PHASE MARGIN
OUTPUT
VOLTAGE SWING
4
VOLTAGE SWING
4
CURRENT, continuous
SLEW RATE
CAPACITIVE LOAD, Av = 10
CAPACITIVE LOAD, Av>10
SETTLING TIME to .1%
POWER SUPPLY
VOLTAGE, V
S4
CURRENT, quiescent
THERMAL
RESISTANCE, AC, junction to case
5
RESISTANCE, DC, junction to case
RESISTANCE, junction to air
TEMPERATURE RANGE, case
NOTES:
*
1.
2.
3.
4.
5.
Full temperature range, F > 60Hz
Full temperature range, F < 60Hz
Full temperature range
Meets full range specifications
Full temperature range
±75
I
O
= 75mA
Full temperature range, I
O
= 20mA
Full temperature range
C
C
= 15pF, A
V
= 100
Full temperature range
Full temperature range
R
L
= 10KΩ, 10V step, Av = 10
R
L
= 10k, C
C
= 15pF
R
L
= 10k, C
C
= 15pF, A
V
= 100
R
L
= 10k, C
C
= 15pF, V
O
= 500V p-p
Full temperature range, A
V
= 10
108
Full temperature range
Full temperature range
Full temperature range, V
CM
=
±90V
10kHz BW, R
S
= 10K, C
C
= 15pF
±V
S
50
96
±
.5
10
7
75
5
.01
5
10
5
4
110
4
120
10
5
60
±
±
2
30
50
50
*
*
.25
5
*
*
3
*
3
*
*
*
.5
10
10
20
mV
µV/°C
µV/V
µV/kh
pA
pA/V
pA
MΩ
pF
V
dB
µV
RMS
dB
MHz
kHz
°
V
V
mA
V/µs
nF
µs
V
mA
°C/W
°C/W
°C/W
°C
*
*
*
*
*
*
*
*
*
*
*
±V
S
30
±V
S
15
±V
S
20
±V
S
12
75
12
16
±
±
1
SOA
2
±500
4.8
2.1
3.3
15
–25
±600
6.0
2.3
3.5
+85
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
*
The specification of PA89A is identical to the specification for PA89 in applicable column to the left.
Unless otherwise noted: T
C
= 25°C, C
C
= 68pF, R
C
= 220Ω, and V
S
=
±500V.
Input parameters for bias currents and offset
voltage are
±
values given.
Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF.
Doubles for every 10°C of temperature increase.
+V
S
and –V
S
denote the positive and negative supply rail respectively.
Rating applies only if the output current alternates between both output transistors at a rate faster than 60Hz.
The PA89 is constructed from MOSFET transistors. ESD handling procedures must be observed.
The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush, machine, or
subject to temperatures in excess of 850°C to avoid generating toxic fumes.
CAUTION
APEX MICROTECHNOLOGY CORPORATION
• 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
PA89 • PA89A
GENERAL
Please read the “General Operating Considerations” sec-
tion, which covers stability, supplies, heatsinking, mounting,
current limit, SOA interpretation, and specification interpreta-
tion. Additional information can be found in the application
notes. For information on the package outline, heatsinks, and
mounting hardware, consult the “Accessory and Package
Mechanical Data” section of the handbook.
OPERATING
CONSIDERATIONS
STABILITY
Although the PA89 can be operated at unity gain, maximum
slew rate and bandwidth performance was designed to be
obtained at gains of 10 or more. Use the small signal response
and phase response graphs as a guide. In applications where
gains of less than 10 are required, use noise gain compensa-
tion to increase the phase margin of the application circuit as
illustrated in the typical application drawing.
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 MOSFET geometry
and the wire bonds.
2. The junction temperature of the output MOSFETs.
NOTE: The output stage is protected against transient flyback.
However, for protection against sustained, high energy flyback,
external fast-recovery diodes should be used.
The compensation capacitance C
C
must be rated for the full
supply voltage range. For example, with supply voltages of
±500V
the possible voltage swing across C
C
is 1000V. In
addition, a voltage coefficient less than 100PPM is recom-
mended to maintain the capacitance variation to less than 5%
for this example. It is strongly recommended to use the highest
quality capacitor possible rated at least twice the total supply
voltage range.
Of equal importance are the voltage rating and voltage
coefficient of the gain setting resistances. Typical voltage
ratings of low wattage resistors are 150 to 250V. In the above
example 1000V could appear across the feedback resistor.
This would require several resistors in series to obtain the
proper voltage rating. Low voltage coefficient resistors will
insure good gain linearity. The wattage rating of the feedback
resistor is also of concern. A 1 megohm feedback resistor
could easily develop 1 watt of power dissipation.
Though high voltage rated resistors can be obtained,
a 1 megohm feedback resistor comprised of five 200Kohm, 1/
4 watt metal film resistors in series will produce the proper
voltage rating, voltage coefficient and wattage rating.
CURRENT LIMIT
For proper operation the current limit resistor (R
CL
) must be
connected as shown in the external connection diagram. The
minimum value is 3.5 ohm, however for optimum reliability the
resistor value should be set as high as possible. The value is
calculated as follows with the maximum practical value of 150
ohms.
R
CL
=
.7
I
LIM
SAFE OPERATING CURVES
The safe operating area curves define the maximum addi-
tional internal power dissipation the amplifier can tolerate when
it produces the necessary output to drive an external load. This
is not the same as the absolute maximum internal power
dissipation listed elsewhere in the specification since the quies-
cent power dissipation is significant compared to the total.
When setting the value for R
CL
allow for the load current as
well as the current in the feedback resistor. Also allow for the
temperature coefficient of the current limit which is approxi-
mately -0.3% /°C of case temperature rise.
EXTERNAL COMPONENTS
The very high operating voltages of the PA89 demand
consideration of two component specifications rarely of con-
cern in building op amp circuits: voltage rating and voltage
coefficient.
OUTPUT CURRENT FROM +V
S
OR –V
S
(mA)
CAUTIONS
The operating voltages of the PA89 are potentially lethal.
During circuit design, develop a functioning circuit at the lowest
possible voltages. Clip test leads should be used for “hands
off” measurements while troubleshooting.
100
10mS
50
30
125°C
25°C
100mS
POWER SUPPLY PROTECTION
Unidirectional zener diode transient absorbers are recom-
mended as protection on the supply pins. The zeners clamp
transients to voltages within the power supply rating and also
clamp power supply reversals to ground. Whether the zeners
are used or not, the system power supply should be evaluated
for transient performance including power-on overshoot and
power-off polarity reversals as well as line regulation.
Conditions which can cause open circuits or polarity rever-
sals on either power supply rail should be avoided or protected
against. Reversals or opens on the negative supply rail is
known to induce input stage failure. Unidirectional transzorbs
prevent this, and it is desirable that they be both electrically and
physically as close to the amplifier as possible.
15
10
85°C
5
T = T
CASE
3
100
200
300
500
800 1000 1200
SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE, V
S
– V
O
(V)
This data sheet has been carefully
CORPORATION
•
to be
NORTH SHANNON ROAD
assumed for possible inaccuracies or
USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
APEX MICROTECHNOLOGY
checked and is believed
5980
reliable, however, no responsibility
•
is
TUCSON, ARIZONA 85741 •
omissions. All specifications are subject to change without notice.
PA89U REV. F FEBRUARY 1998
© 1998 Apex Microtechnology Corp.
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