APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
FEATURES
HIGH VOLTAGE -- 450V (
225V)
LOW QUIESCENT CURRENT -- 2mA
HIGH OUTPUT CURRENT -- 100mA
PROGRAMMABLE CURRENT LIMIT
LOW BIAS CURRENT -- FET Input
APPLICATIONS
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 440V
DESCRIPTION
The PA88 is a high voltage, low quiescent current MOSFET
operational amplifier designed for output currents up to 100mA.
Output voltages can swing up to
215V with a dual supply and
up to +440 volts with a single supply. 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. All internal biasing is
referenced to a bootstrapped zener-MOSFET current source.
As a result, the PA88 features an unprecedented supply range
and excellent supply rejection. The MOSFET output stage is
biased on for linear operation. External compensation pro-
vides user flexibility.
This hybrid circuit utilizes beryllia (BeO) substrates, thick
film resistors, ceramic capacitors and semiconductor chips to
maximize reliability, minimize size and give top performance.
Ultrasonically bonded aluminum wires provide reliable inter-
connections at all operating temperatures. The 8-pin TO-3
package is hermetically sealed and electrically isolated. The
use of compressible thermal isolation washers and/or im-
proper mounting torque will void the product warranty. Please
see "General Operating Considerations".
EQUIVALENT SCHEMATIC
TYPICAL APPLICATION
Piezo positioning may be applied to the focusing of seg-
mented mirror systems. The composite mirror may be com-
posed of hundreds of elements, each requiring focusing under
computer control. In such complex systems the PA88's advan-
tage of low quiescent power consumption reduces the costs of
power supplies and cooling, while providing the interface
between the computer and the high voltage drive to the piezo
positioners.
EXTERNAL CONNECTIONS
LOW POWER, PIEZOELECTRIC POSITIONING
F
R
PA88
IN
R
PIEZO DRIVE
S
V
S
+V
OUT
V
C
C
COMPUTER
FOCUS
COMMAND
VOLTAGE
1
2
3
4
5
6
7
8
TOP VIEW
CL
+Vs
+IN
Vs
COMP
OUT
R
CL
IN
C
C
PHASE COMPENSATION
GAIN
C
C
1
10
20
100
68pf
33pf
15pf
3.3pf
COMP
R
C
100
100
100
--
R
C
R
CL
=
.7
I
LIM
C
C
RATED FOR FULL
SUPPLY VOLTAGE
PATENTED
2
1
3
6
4
5
8
7
+ IN
COMP
CL
OUT
+V
S
V
S
Q1
Q2
Q4
Q8
Q9
Q6
Q7
Q12
Q10A
Q10B
Q11
Q17
Q13
Q16
Q18
D2
D19
D1
IN
H T T P : / / W W W . A P E X M I C R O T E C H . C O M ( 8 0 0 ) 5 4 6 - A P E X ( 8 0 0 ) 5 4 6 - 2 7 3 9
M I C R O T E C H N O L O G Y
HIGH VOLTAGE POWER OPERATIONAL AMPLIFIERS
PA88 PA88A
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
to V
S
450V
OUTPUT CURRENT, source, sink
See SOA
POWER DISSIPATION, continuous @ T
C
= 25
C
15W
INPUT VOLTAGE, differential
25V
INPUT VOLTAGE, common mode
V
S
TEMPERATURE, pin solder - 10s max
300
C
TEMPERATURE, junction
2
150
C
TEMPERATURE, storage
65 to +150
C
OPERATING TEMPERATURE RANGE, case
55 to +125
C
PA88 PA88A
SPECIFICATIONS
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
1
5
*
*
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
2.5
100
3
20
pA
INPUT IMPEDANCE, DC
10
11
*
INPUT CAPACITANCE
4
*
pF
COMMON MODE VOLTAGE RANGE
4
V
S
12
*
V
COMMON MODE REJECTION, DC
V
CM
=
90V
90
110
*
*
dB
NOISE
100kHz BW, R
S
= 1K
, C
C
= 15pf
2
*
Vrms
GAIN
OPEN LOOP, @ 15Hz
R
L
= 2K
, C
C
= OPEN
96
111
*
*
dB
GAIN BANDWIDTH PRODUCT at 1MHz R
L
= 2K
, C
C
= 15pf, R
C
= 100
2.1
*
MHz
POWER BANDWIDTH
R
L
= 2K
, C
C
= 15pf, R
C
= 100
6
*
kHz
PHASE MARGIN
Full temperature range
60
*
OUTPUT
VOLTAGE SWING
4
I
O
=
100mA
V
S
12
V
S
9.8
*
*
V
VOLTAGE SWING
4
Full temp. range, I
O
=
75mA
V
S
8.5
V
S
7.5
*
*
V
VOLTAGE SWING
4
Full temp. range, I
O
=
20mA
V
S
8.0
V
S
5.2
*
*
V
CURRENT, continuous
T
C
= 85
C
100
*
mA
SLEW RATE, A
V
= 20
C
C
= 15pf, R
C
= 100
8
*
V/
s
SLEW RATE, A
V
= 100
C
C
= OPEN
30
*
V/
s
CAPACITIVE LOAD, A
V
= +1
Full temperature range
470
*
pf
SETTLING TIME to .1%
C
C
= 15pf, R
C
= 100
, 2V step
10
*
s
RESISTANCE, no load
R
CL
= 0
100
*
POWER SUPPLY
VOLTAGE
6
See note 6
15
200
225
*
*
*
V
CURRENT, quiescent,
1.7
2
*
*
mA
THERMAL
RESISTANCE, AC, junction to case
5
Full temperature range, F > 60Hz
5.0
*
C/W
RESISTANCE, DC, junction to case
Full temperature range, F < 60Hz
8.3
*
C/W
RESISTANCE, junction to air
Full temperature range
30
*
C/W
TEMPERATURE RANGE, case
Meets full range specifications
25
+85
*
*
C
PA88A
PA88
NOTES:
*
The specification of PA88A is identical to the specification for PA88 in applicable column to the left.
1.
Unless otherwise noted: T
C
= 25
C, compensation = C
C
= 68pF, R
C
= 100
. DC input specifications are
value given. Power
supply voltage is typical rating.
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 10
C of temperature increase.
4.
+V
S
and V
S
denote the positive and negative power supply rail respectively.
5.
Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz.
6.
Derate max supply rating .625 V/
C below 25
C case. No derating needed above 25
C case.
The PA88 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 TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
TYPICAL PERFORMANCE
GRAPHS
PA88 PA88A
0
25
50
75
100
125
150
TEMPERATURE, T (C)
0
2.5
7.5
10
POWER DERATING
INTERNAL POWER DISSIPATION, P(W)
1
100
1K
1M
FREQUENCY, F (Hz)
210
180
60
0
PHASE RESPONSE
PHASE, ()
10
100
10K
1M
FREQUENCY, F (Hz)
INPUT NOISE VOLTAGE, V (nV/ Hz)
1
10M
FREQUENCY, F (Hz)
20
0
60
120
SMALL SIGNAL RESPONSE
OPEN LOOP GAIN, A (dB)
20
40
80
100
0
100
OUTPUT CURRENT, I (mA)
2
4
8
12
OUTPUT VOLTAGE SWING
6
10
1K
2K
100K
FREQUENCY, F (Hz)
25
125
500
OUTPUT VOLTAGE, V (V )
O
75
250
1
10
1M
FREQUENCY, F (Hz)
20
80
COMMON MODE REJECTION
COMMON MODE REJECTION, CMR (dB)
40
60
100
1
1M
FREQUENCY, F (Hz)
20
40
140
POWER SUPPLY REJECTION
POWER SUPPLY REJECTION, PSR (dB)
60
100
3
10
20
100
CURRENT LIMIT RESISTOR, R
CL
( )
10
30
200
CURRENT LIMIT
CURRENT LIMIT, I (mA)
LIM
50
70
0
50
COMPENSATION CAPACITOR, C
C
(pF)
1
SLEW RATE
SLEW RATE, (V/ S)
2
50
70
10
30
3
FREQUENCY, F (Hz)
.001
HARMONIC DISTORTION
DISTORTION, (%)
1
10
30K
30
300
3K
0
100
300
TOTAL SUPPLY VOLTAGE, V (V)
1.0
2.0
QUIESCENT CURRENT
QUIESCENT CURRENT, I (mA)
Q
1.75
S
1K
10K
5
50
20
INPUT NOISE
1K
2
7
10
20
3
5
15
N
O
20
VOLTAGE DROP FROM SUPPLY, V V (V)
SO
10
10K .1M
120
5
15
POWER RESPONSE
PP
5K
10
100
1K
10K .1M
80
200
1.25
1.5
.0001
100 1K 10K .1M 1M
150
90
450
2.25
2.5
60
50
20
20
60
.01
.1
120
120
12.5
T = 125C
C
T = 25C
C
T = -55C
C
10
40
30
10K 20K
50K
R
L
= 2K
P
O
= 2.5W
A
V
= 30
100
.1M
C = 15pF
C
C = 33pF
C
C = 68pF
C
C = 3.3pF
C
10M
C = 33pF
C
C = 3.3pF
C
C = 68pF
C
C = 3.3pF
C
C = 68pF
C
C = 33pF
C
120
100
150
C = 3.3pf
C
C = 15pf
C
C = 33pf
C
C = 68pf
C
3K
100
40
3
5
10
30
T = 25C
C
T = 55C
C
T = 125C
C
T = 85C
C
80
T = T
C
T = T
A
OPERATING
CONSIDERATIONS
PA88 PA88A
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.
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
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.
INPUT PROTECTION
Although the PA88 can withstand differential input voltages
up to
25V, additional external protection is recommended,
and required at total supply voltages above 300 volts. In most
SUPPLY TO OUTPUT DIFFERENTIAL, V
S
V
O
(V)
25
50
75
100
250
500
OUTPUT CURRENT FROM +V
S
OR V
S
, (mA)
5
10
15
25
50
100
150
250
DC, T
C
= 125C
DC, T
C
= 85C
200mS
PULSE CURVES @ 10% DUTY CYCLE MAX
DC, T
C
= 25C
100mS
125
applications 1N4148 or 1N914 signal diodes are sufficient (D1,
D2 in Figure 2a). In more demanding applications where low
leakage or low capacitance are of concern 2N4416 or 2N5457-
2N5459 JFETs connected as diodes will be required (Q1, Q2
in Figure 2b). In either case the input differential voltage will be
clamped to
.7V. This is sufficient overdrive to produce maxi-
mum power bandwidth.
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors 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 reversal 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.
STABILITY
The PA88 has sufficient phase margin to be stable with most
capacitive loads at a gain of 4 or more, using the recommended
phase compensation.
The PA88 is externally compensated and performance can
be tailored to the application. Use the graphs of small signal
response and power response as a guide. The compensation
capacitor C
C
must be
rated at 500V working
voltage. An NPO capaci-
tor is recommended. The
compensation network
C
C
R
C
must be mounted
closely to the amplifier
pins 7 and 8 to avoid
spurious oscillation.
FIGURE 2. OVERVOLTAGE PROTECTION
PA88
+V
S
IN
+IN
Z1
Z2
D2
D1
3
6
5
4
+V
S
IN
+IN
Z1
Z2
3
6
5
4
PA88
Q1
Q2
a.
b.
V
S
V
S
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.
PA88U REV. I MARCH 1999
1999 Apex Microtechnology Corp.
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