PA91
High Voltage Power Operational Amplifiers
RoHS
COMPLIANT
FEATURES
•
•
•
•
•
High Voltage — 450V (±225V)
Low Quiescent Current — 10mA
High Output Current — 200mA
Programmable Current Limit
High Slew Rate— 300V/µs
APPLICATIONS
•
•
•
•
Piezoelectric Positioning
High Voltage Instrumentation
Electrostatic Transducers
Programmable Power Supplies up to 440V
DESCRIPTION
The PA91 is a high voltage, low quiescent current MOSFET operational amplifier designed as a low cost
solution for driving continuous output currents up to 200mA and pulse currents up to 350mA. The safe operating area (SOA) has no second breakdown limitations and can be observed for all load types by choosing an
appropriate current limiting resistor. The MOSFET output stage is biased AB for linear operation. External
compensation provides flexibility in choosing bandwidth and slew rate for the application. Apex Microtechnology’s Power SIP uses a minimum of board space allowing for high density circuit boards. The 12-pin Power
SIP is electrically isolated.
Figure 1: Equivalent Schematic
12
11
+VS
R1 R2
Q1
C1
R3
Q3
Q2
R4
Q4
5
Q6
4
Q5
Q14A
Q8
CC1
Q14B
1
–IN
ICL
9
CC2
R7
6
OUT
R6
R5
R8
R9
Q12
Q13
3
IQ
2
+IN
Q15
R11
10
Q11
R10
Q17
Q16
R12
–VS
7
8
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© Apex Microtechnology Inc.
All rights reserved
Dec 2019
PA91U Rev O
PA91
TYPICAL CONNECTION
Figure 2: Typical Connection
RF
+V S
*
100 k
100nF
RC
CC
RF
+V S
+
PA91
-V S
RCL
CC
CL
RL
-V S
* Use 10μF per Amp
of Output Current.
*
2
V OUT
RC
1k
100nF
PA91U Rev O
PA91
PINOUT AND DESCRIPTION TABLE
Figure 3: External Connections
Pin Number
Name
Description
1
2
-IN
+IN
3
IQ
4
RC
5
CC
6
OUT
7, 8
-VS
9, 10
CL
11, 12
+VS
The inverting input.
The non-inverting input.
Quiescent current reduction pin. Connect to pin 5 to disable the AB bias.
See applicable section.
Compensation resistor connection. Select value based on Phase Compensation.
See applicable section.
Compensation capacitor connection. Select value based on Phase Compensation.
See applicable section.
The output. Connect this pin to load and to the feedback resistors.
The negative supply rail. Pins 7 and 8 are not internally connected and must be
shorted.
Connect to the current limit resistor. Output current flows into/out of these pins
through RCL. The output pin and the load are connected to the other side of
RCL. Pins 9 and 10 are internally connected.
The positive supply rail. Pins 11 and 12 are internally connected.
PA91U Rev O
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PA91
SPECIFICATIONS
All Min/Max characteristics and specifications are guaranteed over the Specified Operating Conditions.
Typical performance characteristics and specifications are derived from measurements taken at typical supply voltages and TC = 25°C
ABSOLUTE MAXIMUM RATINGS
Parameter
Symbol
Supply Voltage, total
Output Current, source, sink, peak, within SOA
Power Dissipation, continuous @ Tc = 25°C
Input Voltage, differential
Input Voltage, common mode
Min
Max
Units
+VS to -VS
450
V
IOUT
350
mA
PD
30
W
VIN (Diff)
-20
20
V
VCM
-VS
VS
V
260
°C
150
°C
-55
+125
°C
-40
+85
°C
Temperature, pin solder, 10s max.
Temperature, junction
Temperature Range, storage
TJ
Operating Temperature Range, case
TC
1
1. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation to achieve high MTTF.
CAUTION
The PA91 is constructed from MOSFET transistors. ESD handling procedures must be observed.
The substrate contains beryllia (BeO). Do not crush, machine, or subject to temperatures in
excess of 850°C to avoid generating toxic fumes.
INPUT
Parameter
Offset Voltage, initial
Offset Voltage vs. Temperature
Offset Voltage vs. Supply
Offset Voltage vs. Time
Bias Current, initial
Bias Current vs. Supply
Offset Current, initial
Test Conditions
Min
Full temp range
Input Impedance, DC
Input Capacitance
Common Mode Voltage Range 1
Typ
Max
Units
0.5
15
10
75
200
4
50
2
50
25
mV
µV/°C
µV/V
µV/kh
pA
pA/V
pA
VCM = ±90V
Noise
100 kHz bandwidth,
RS = 1 kΩ, CC = OPEN
80
500
1011
Ω
4
pF
V
±VS Ŧ 15
Common Mode Rejection, DC
2000
98
dB
1
µV RMS
1. +VS and –VS denote the positive and negative power supply rail respectively.
4
PA91U Rev O
PA91
GAIN
Parameter
Min
Typ
94
111
dB
Gain Bandwidth Product @ 1 MHz RL = 2 kΩ, CC = OPEN
100
MHz
Power Bandwidth
RL = 2 kΩ, CC = OPEN
470
kHz
Phase Margin
Full temp range
60
°
Open Loop @ 15 Hz
Test Conditions
RL = 2 kΩ, CC = OPEN
Max
Units
OUTPUT
Parameter
Test Conditions
Min
Typ
±VS Ŧ 12
±VS Ŧ 10
Voltage Swing 1
IOUT = 200mA
Current, continuous
Slew Rate, A V = 100
CC = OPEN
240
Capacitive Load, AV = +1
Full temp range
470
Settling Time to 0.1%
CC = OPEN, 2V step
Max
V
200
Resistance, no load
Units
mA
300
V/µs
pF
1
µs
50
Ω
1. +VS and –VS denote the positive and negative power supply rail respectively.
POWER SUPPLY
Parameter
Test Conditions
Min
Typ
Max
Units
±40
±150
±225
V
10
14
mA
Max
Units
Full temp range, F > 60 Hz
2.5
°C/W
Full temp range, F < 60 Hz
Full temp range
Meets full range specs
4.2
°C/W
°C/W
°C
Voltage 1
Current, quiescent
1. Derate max supply rating 0.625 V/°C below 25°C case. No derating needed above 25°C case.
THERMAL
Parameter
Resistance, AC, junction to case 1
Resistance, DC, junction to case
Resistance, junction to air
Temperature Range, case
Test Conditions
Min
Typ
30
-25
+85
1. Rating applies if the output current alternates between both output transistors at a rate faster than 60 Hz.
PA91U Rev O
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PA91
TYPICAL PERFORMANCE GRAPHS
Figure 4: Power Derating
Figure 5: Normalized Quiescent Current
1.3
Normalized Quiescent Current, IQ (X)
/ŶƚĞƌŶĂůWŽǁĞƌŝƐƐŝƉĂƟŽŶ͕W;t)
40
32
Output Stage
24
16
8
0
0
25
50
75
100
125
1.2
1.1
1.0
25
150
Case Temperature, TC (°C)
50
75
100
125
Case Temperature, TC (°C)
Figure 6: Small Signal Response
Figure 7: Phase Response
90
50
135
30
Phase, ˇ;Σ)
Open Loop Gain, A (dB)
40
20
10
0
CC = 68pF
CC = 10pF
CC = 4.7pF
CC = OPEN
-10
100k
225
1M
Frequency, F (Hz)
6
180
10M
270
100k
CC = 68pF
CC = 10pF
CC = 4.7pF
CC = OPEN
1M
10M
Frequency, F (Hz)
PA91U Rev O
PA91
Figure 9: Power Response
500
6
5.5
100
90
80
70
60
50
10k
Output Current, IOUT (A)
100k
1M
Frequency, F (Hz)
Figure 10: Slew Rate
Figure 11: Harmonic Distortion
1000
700
500
1
300
0.1
ŝƐƚŽƌƟŽŶ;й)
Slew Rate (V/μs)
N
OPE
0.2
CC=
0.15
F
0.1
4.7p
0.05
CC=
0
F
3.5
10p
4
F
4.5
200
CC=
5
300
68p
Output Voltage, VOUT (VP-P)
400
CC=
Voltage Drop From Supply, VS-VOUT (V)
Figure 8: Output Voltage Swing
200
100
70
40
30
RLсϭŬɏ
VS = 200V
AV = 63
PO = 17.6W
PO = 1W
0.01
PO = 5W
20
10
0.1
0.001
1
10
džƚ͘ŽŵƉĞŶƐĂƟŽŶĂƉĂĐŝƚŽƌ͕C (pF)
PA91U Rev O
100
10
100
1k
10k
100k
Frequency, F (Hz)
7
PA91
Figure 12: Input Noise Voltage
Figure 13: Current Limit
0.2
15
Current Limit, ICL (A)
Input Noise Voltage, V (Ŷsͬя,nj)
20
10
7
5
0.1
0.05
3
2
10
0
100
1k
Frequency, F (Hz)
8
0.15
10k
100k
0
4
8
12
16
20
24
Resistor Value, RCL (ɏ)
PA91U Rev O
PA91
SAFE OPERATING AREA (SOA)
The safe operating area curves define the maximum additional internal power dissipation the amplifier
can tolerate when it produces the necessary output to drive an external load.
The MOSFET output stage of this power operational amplifier 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.
Figure 14: SOA
KƵƚƉƵƚƵƌƌĞŶƚ&ƌŽŵнVS ŽƌͲVS ;ŵA)
500
ϮϬ
300
Ϭŵ
ϭϬ
Ϭŵ
Ɛ
200
Ɛ
͕d
100
͕d
C
͕d
50
C
=2
C
5°
=8
C
5°
C
=1
25
30
°C
20
10
25
50
75 100 125
250
500
^ƵƉƉůLJƚŽKƵƚƉƵƚŝīĞƌĞŶƟĂů͕VS-VOUT (V)
PA91U Rev O
9
PA91
GENERAL
Please read Application Note 1 “General Operating Considerations” which covers stability, supplies, heat
sinking, mounting, current limit, SOA interpretation, and specification interpretation. Visit www.apexanalog.com for Apex Microtechnology’s complete Application Notes library, Technical Seminar Workbook, and
Evaluation Kits.
TYPICAL APPLICATION
LOW POWER, PIEZOELECTRIC POSITIONING
Piezo positioning may be applied to the focusing of segmented mirror systems. The composite mirror
may be composed of hundreds of elements, each requiring focusing under computer control. In such complex systems the PA91 reduces the costs of power supplies and cooling with its advantages of low cost and
low quiescent power consumption while increasing circuit density with the SIP package.
Figure 15: Typical Application
PHASE COMPENSATION
Gain
CC*
RC
≥1
≥5
≥10
≥30
68pF
10pF
4.7pF
NONE
100 Ω
100 Ω
0Ω
0Ω
*CC To be rated for the full supply voltage +VS to –VS. Use NPO ceramic (COG) type.
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PA91U Rev O
PA91
CURRENT LIMIT
For proper operation, the current limit resistor (RCL) must be connected as shown in the typical connection diagram. 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 32 ohms.
0.65V
R CL = ---------------I CL A
INPUT PROTECTION
Although the PA91 can withstand differential voltages up to ±20V, additional external protection is recommended. Low leakage, low capacitance JFETs connected as diodes are recommended (e.g. 2N4416, Q1-Q4
in Figure 16). The differential input voltage will be clamped to ±1.4V. This is sufficient overdrive to produce
maximum power bandwidth.
Figure 16: Overvoltage Protection
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are recommended as protection on the supply pins. See
Figure 16. 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 are 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.
PA91U Rev O
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PA91
STABILITY
The PA91 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 CC must be rated at
500V working voltage. An NPO capacitor is recommended. The compensation network CCRC must be
mounted closely to the amplifier pins 4 and 5 to avoid spurious oscillation.
QUIESCENT CURRENT REDUCTION
When pin 3 (IQ) is shorted to pin 5 (CC2) the AB biasing of the output stage is disabled. This raises distortion since the output stage is then class C biased, but reduces the quiescent current by 1mA for a power dissipation savings of 0.4W. Pin 3 may be left open if not used.
12
PA91U Rev O
PA91
PACKAGE OPTIONS
Part Number
Apex Package Style
Description
PA91
PA91EE
DP
EE
12-Pin SIP
12-Pin SIP w/ formed leads
PACKAGE STYLE DP
PA91U Rev O
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PA91
PACKAGE STYLE EE
NEED TECHNICAL HELP? CONTACT APEX SUPPORT!
For all Apex Microtechnology product questions and inquiries, call toll free 800-546-2739 in North America. For
inquiries via email, please contact apex.support@apexanalog.com. International customers can also request
support by contacting their local Apex Microtechnology Sales Representative. To find the one nearest to you,
go to www.apexanalog.com
IMPORTANT NOTICE
Apex Microtechnology, Inc. has made every effort to insure the accuracy of the content contained in this document. However, the information is
subject to change without notice and is provided "AS IS" without warranty of any kind (expressed or implied). Apex Microtechnology reserves the right
to make changes without further notice to any specifications or products mentioned herein to improve reliability. This document is the property of
Apex Microtechnology and by furnishing this information, Apex Microtechnology grants no license, expressed or implied under any patents, mask
work rights, copyrights, trademarks, trade secrets or other intellectual property rights. Apex Microtechnology owns the copyrights associated with the
information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Apex
Microtechnology integrated circuits or other products of Apex Microtechnology. This consent does not extend to other copying such as copying for
general distribution, advertising or promotional purposes, or for creating any work for resale.
APEX MICROTECHNOLOGY PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED TO BE SUITABLE FOR USE IN PRODUCTS USED FOR LIFE
SUPPORT, AUTOMOTIVE SAFETY, SECURITY DEVICES, OR OTHER CRITICAL APPLICATIONS. PRODUCTS IN SUCH APPLICATIONS ARE UNDERSTOOD TO BE
FULLY AT THE CUSTOMER OR THE CUSTOMER’S RISK.
Apex Microtechnology, Apex and Apex Precision Power are trademarks of Apex Microtechnology, Inc. All other corporate names noted herein may be
trademarks of their respective holders.
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PA91U Rev O
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