APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
1
EXTERNAL CONNECTIONS
TYPICAL APPLICATION
Ultra-high voltage capability combined with the bridge ampli-
fier 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.
PATENTED
PHASE COMPENSATION
Gain
C
C
R
C
1
470pF
470
10
68pF
220
15
33pF
220
100
15pF
220
Note: C
C
must be rated for full supply voltage Vs to +Vs.
See details under "EXTERNAL COMPONENTS".
FEATURES
1140V P-P SIGNAL OUTPUT
WIDE SUPPLY RANGE -- 75V to 600V
PROGRAMMABLE CURRENT LIMIT
75 mA CONTINUOUS OUTPUT CURRENT
HERMETIC SEALED PACKAGE
INPUT PROTECTION
APPLICATIONS
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC DEFLECTION
SEMICONDUCTOR TESTING
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 semiconduc-
tor 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 DipTM package is hermetically
sealed and electrically isolated. The use of compressible
thermal washers will void the product warranty.
SIMPLIFIED SCHEMATIC
HIGH VOLTAGE MO-127
PACKAGE STYLE DC
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
2
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
PA89 PA89A
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
to V
S
1200V
OUTPUT CURRENT, within SOA
100mA
POWER DISSIPATION, internal at T
C
= 25C
40W
INPUT VOLTAGE, differential
25V
INPUT VOLTAGE, common mode
V
S
25V
TEMPERATURE, pin solder - 10s max
300C
TEMPERATURE, junction
2
150C
TEMPERATURE, storage
65 to 125C
OPERATING TEMPERATURE RANGE, case
55 to 125C
PA89
PA89A
PARAMETER
TEST CONDITIONS
1
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
INPUT
OFFSET VOLTAGE, initial
.5
2
.25
.5
mV
OFFSET VOLTAGE, vs. temperature
Full temperature range
10
30
5
10
V/C
OFFSET VOLTAGE, vs. supply
7
*
V/V
OFFSET VOLTAGE, vs. time
75
*
V/kh
BIAS CURRENT, initial
3
5
50
3
10
pA
BIAS CURRENT,vs. supply
.01
*
pA/V
OFFSET CURRENT, initial
3
5
50
3
20
pA
INPUT IMPEDANCE, DC
10
5
*
M
INPUT CAPACITANCE
4
*
pF
COMMON MODE VOLTAGE RANGE
4
Full temperature range
V
S
50
*
V
COMMON MODE REJECTION, DC
Full temperature range, V
CM
= 90V
96
110
*
*
dB
INPUT NOISE
10kHz BW, R
S
= 10K, C
C
= 15pF
4
V RMS
GAIN
OPEN LOOP GAIN at 10Hz
R
L
= 10k, C
C
= 15pF
108
120
*
*
dB
GAIN BANDWIDTH PRODUCT
R
L
= 10k, C
C
= 15pF, A
V
= 100
10
*
MHz
POWER BANDWIDTH
R
L
= 10k, C
C
= 15pF, V
O
= 500V p-p
5
*
kHz
PHASE MARGIN
Full temperature range, A
V
= 10
60
*
OUTPUT
VOLTAGE SWING
4
I
O
= 75mA
V
S
45 V
S
30
*
*
V
VOLTAGE SWING
4
Full temperature range, I
O
= 20mA
V
S
20 V
S
12
*
*
V
CURRENT, continuous
Full temperature range
75
*
mA
SLEW RATE
C
C
= 15pF, A
V
= 100
12
16
*
*
V/s
CAPACITIVE LOAD, Av = 10
Full temperature range
1
*
nF
CAPACITIVE LOAD, Av>10
Full temperature range
SOA
*
SETTLING TIME to .1%
R
L
= 10K, 10V step, Av = 10
2
*
s
POWER SUPPLY
VOLTAGE, V
S
4
Full temperature range
75
500
600
*
*
*
V
CURRENT, quiescent
4.8
6.0
*
*
mA
THERMAL
RESISTANCE, AC, junction to case
5
Full temperature range, F > 60Hz
2.1
2.3
*
*
C/W
RESISTANCE, DC, junction to case
Full temperature range, F < 60Hz
3.3
3.5
*
*
C/W
RESISTANCE, junction to air
Full temperature range
15
*
C/W
TEMPERATURE RANGE, case
Meets full range specifications
25
+85
*
*
C
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 850C to avoid generating toxic fumes.
CAUTION
NOTES: * The specification of PA89A is identical to the specification for PA89 in applicable column to the left.
1. Unless otherwise noted: T
C
= 25C, C
C
= 68pF, R
C
= 220, and V
S
= 500V. Input parameters for bias currents and offset volt-
age are values given.
2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to
achieve high MTTF.
3. Doubles for every 10C of temperature increase.
4. +V
S
and V
S
denote the positive and negative supply rail respectively.
5. Rating applies only if the output current alternates between both output transistors at a rate faster than 60Hz.
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
4
OPERATING
CONSIDERATIONS
PA89 PA89A
GENERAL
Please read Application Note 1 "General Operating Con-
siderations" which covers stability, supplies, heat sinking,
mounting, current limit, SOA interpretation, and specification
interpretation. Visit www.apexmicrotech.com for design tools
that help automate tasks such as calculations for stability,
internal power dissipation, current limit; heat sink selection;
Apex's complete Application Notes library; Technical Seminar
Workbook; and Evaluation Kits.
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.
SAFE OPERATING CURVES
The safe operating area curves define the maximum ad-
ditional 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 quiescent power dissipation is significant compared to
the total.
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.
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 coef-
ficient 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.
.7
R
CL
=
I
LIM
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.
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.
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 reversals
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.
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
PA89U REV H MAY 2005 2005 Apex Microtechnology Corp.
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