®
Product
Innovation From
PA90
PA90
PA90
DESCRIPTION
The PA90 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 oper-
ating area (SOA) has no second breakdown limitations
and can be observed for all type loads by choosing
an appropriate current limiting resistor. The MOSFET
output stage is biased AB for linear operation. Exter-
nal compensation provides flexibility in choosing band-
width and slew rate for the application. Apex Precision
Power’s Power SIP package uses a minimum of board
space allowing for high density circuit boards. The 12-
pin PowerSIP package is electrically isolated.
High Voltage Power Operational Amplifiers
FEATURES
♦ HIGH VOLTAGE — 400V (±200V)
♦ 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 390V
12
11
+V
S
EQUIVALENT SCHEMATIC
R1 R2
C1
R3
Q1
Q6
Q5
Q14A
1
–IN
R5
R8
2
+IN
Q15
R11
Q2
5
CC2
Q3
R4
Q4
ILIM
9
4
CC1
Q14B
R6
R9
Q8
Q11
R7
10
6
OUT
Q12
3
I
Q
Q16
Q13
R10
Q17
–V
S
7
8
R12
EXTERNAL CONNECTIONS
1
2
3
Rc
–IN
+IN
4
5
Cc
R
CL
6
7
8
9
10
11
12
*
I
Q
TO LOAD
AND FEEDBACK
–Vs
+Vs
*
Formed leads available
See package EE
12-pin SIP
PACKAGE
STYLE DP
(See text.)
* Bypassing required.
PA90U
www.cirrus.com
Copyright © Cirrus Logic, Inc. 2010
(All Rights Reserved)
MAR 2010
1
APEX − PA90UREVK
PA90
®
Product Innovation From
1. CHARACTERISTICS AND SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
Parameter
SUPPLY VOLTAGE, +V
S
to -V
S
OUTPUT CURRENT, source, sink, peak, within SOA
POWER DISSIPATION, continuous @ T
C
= 25°C
INPUT VOLTAGE, differential
INPUT VOLTAGE, common mode
TEMPERATURE, pin solder, 10s max.
TEMPERATURE, junction (Note 2)
TEMPERATURE RANGE, storage
OPERATING TEMPERATURE RANGE, case
−40
−25
-20
-V
S
Symbol
Min
Max
400
350
30
20
V
S
260
150
85
85
Units
V
mA
W
V
V
°C
°C
°C
°C
CAUTION
The PA90 is constructed from MOSFET transistors. ESD handling procedures must be observed.
The exposed substrate contains beryllia (BeO). Do not crush, machine, or subject to temperatures
in excess of 850°C to avoid generating toxic fumes.
SPECIFICATIONS
Parameter
AMPLIFIER INPUT
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
INPUT IMPEDANCE, DC
INPUT CAPACITANCE
COMMON MODE VOLTAGE RANGE
(Note 3)
COMMON MODE REJECTION, DC
NOISE
GAIN
OPEN LOOP @ 15Hz
GAIN BANDWIDTH PRODUCT @ 1MHz
POWER BANDWIDTH
PHASE MARGIN
OUTPUT
VOLTAGE SWING (Note 3)
CURRENT, continuous
SLEW RATE, A
V
= 100
CAPACITIVE LOAD, A
V
= +1
2
C
C
= OPEN
Full temperature range
I
O
= 200mA
±V
S
Ŧ 12
200
240
470
300
±V
S
Ŧ 10
V
mA
V/µS
pF
PA90U
R
L
= 2KΩ, C
C
= OPEN
R
L
= 2KΩ, C
C
= OPEN
R
L
= 2KΩ, C
C
= OPEN
Full temperature range
94
111
100
470
60
dB
MHz
kHz
°
V
CM
= ±90V
100KHz bandwidth, R
S
= 1KΩ,
C
C
= OPEN
±V
S
Ŧ 15
80
98
1
Full temperature range
0.5
15
10
75
200
4
50
10
11
4
500
2000
2
50
25
mV
µV/°C
µV/V
µV/kHz
pA
pA/V
pA
Ω
pF
V
dB
µV RMS
Test Conditions
1
Min
Typ
Max
Units
®
Product Innovation From
PA90
Test Conditions
1
Min
Typ
1
50
±40
±150
10
±200
14
2.5
4.2
30
-25
+85
Parameter
SETTLING TIME to 0.1%
RESISTANCE, no load
POWER SUPPLY
VOLTAGE (Note 5)
CURRENT, quiescent
THERMAL
Max
Units
µS
Ω
V
mA
°C/W
°C/W
°C/W
°C
C
C
= OPEN, 2V step
RESISTANCE, AC, junction to case (Note 4) Full temp range, F > 60Hz
RESISTANCE, DC, junction to case
RESISTANCE, junction to air
TEMPERATURE RANGE, case
Full temp range, F < 60Hz
Full temp range
Meets full range specifications
NOTES: 1. (All Min/Max characteristics and specifications are guaranteed over the Specified Operating Condi-
tions. Typical performance characteristics and specifications are derived from measurements taken
at typical supply voltages and T
C
= 25°C).
2. Long term operation at the maximum junction temperature will result in reduced product life. Derate
power dissipation to achieve high MTTF.
3. +V
S
and –V
S
denote the positive and negative power supply rail respectively.
4. Rating applies if the output current alternates between both output transistors at a rate faster than
60Hz.
5. Derate max supply rating .625 V/°C below 25°C case. No derating needed above 25°C case.
TYPICAL APPLICATION
R
F
+V
S
LOW POWER, PIEZOELECTRIC POSITIONING
Piezo positioning may be applied to the focusing of segment-
ed mirror systems. The composite mirror may be composed
of hundreds of elements, each requiring focusing under com-
puter control. In such complex systems the PA90 reduces
the costs of power supplies and cooling with its advantages
of low cost and low quiescent power consumption while in-
creasing circuit density with the SIP package.
R
IN
1
11,12
PIEZO DRIVE
PA90
6
V
OUT
2
COMPUTER
FOCUS
COMMAND
VOLTAGE
7,8
9,10
R
CL
TYPICAL PERFORMANCE GRAPHS
INTERNAL POWER DISSIPATION, P(W)
–V
S
90
NORMALIZED QUIESCENT CURRENT, I
Q
(X)
40
32
24
16
8
0
POWER DERATING
PHASE RESPONSE
NORMALIZED QUIES. CURRENT
1.3
135
PHASE, Ф (°)
1.2
180
C
C
= 68 pF
C
C
= 10 pF
C
C
= 4.7 pF
C
C
= OPEN
1M
10M
FREQUENCY F (Hz)
1.1
225
0
25
50
75 100 125 150
CASE TEMPERATURE, T
C
(°C)
270
100k
1.0
25
50
100
75
125
CASE TEMPERATURE, T
C
(°C)
SMALL SIGNAL RESPONSE
50
LOOP GAIN, A (dB)
P FROM SUPPLY, V
S
– V
O
(V)
6
5.5
5
4.5
OUTPUT VOLTAGE SWING
400
T VOLTAGE, V
O
(V
P-P
)
POWER RESPONSE
300
40
30
C
C
=
PA90U
20
10
200
3
C
C
=
OPE
C
C
=
4.7p
C
C
=
68
N
10p
F
F
INTERNAL POWER DISSIPATION, P(W)
90
NORMALIZED QUIESCENT CURRENT, I
Q
(X)
40
32
24
16
8
0
POWER DERATING
PHASE RESPONSE
NORMALIZED QUIES. CURRENT
1.3
135
PHASE, Ф (°)
1.2
180
C
C
= 68 pF
C
C
= 10 pF
C
C
= 4.7 pF
®
C
C
= OPEN
1.1
225
PA90
0
25
50
75 100 125 150
CASE TEMPERATURE, T
C
(°C)
Product Innovation From
270
100k
1M
10M
FREQUENCY F (Hz)
1.0
25
50
100
75
125
CASE TEMPERATURE, T
C
(°C)
SMALL SIGNAL RESPONSE
50
OPEN LOOP GAIN, A (dB)
VOLTAGE DROP FROM SUPPLY, V
S
– V
O
(V)
6
5.5
5
4.5
4
3.5
OUTPUT VOLTAGE SWING
400
OUTPUT VOLTAGE, V
O
(V
P-P
)
POWER RESPONSE
300
40
30
20
10
C
C
=
200
C
C
=
OPE
C
C
=
4.7p
C
C
=
N
10p
F
100
80
70
60
50
F
68p
C
C
= 68 pF
0 C
C
= 10 pF
C
C
= 4.7 pF
–10 C
C
= OPEN
100K
1M
10M
FREQUENCY, F (Hz)
F
0
0.1
.05
0.15
OUTPUT CURRENT, I
O
(A)
0.2
10K
1M
100K
FREQUENCY, F (Hz)
SLEW RATE, (V/μS)
DISTORTION, (%)
300
200
100
70
50
40
30
20
10
0.1
10
100
1
EXT. COMPENSATION CAPACITOR, C
C
(pF)
R
L
= 1KΩ
V
S
= 200V
A
V
= 63
.1
P
O
= 17.6W
.01
P
O
= 1W
P
O
= 5W
INPUT NOISE VOLTAGE, V (nV√Hz)
1K
700
500
SLEW RATE
1
HARMONIC DISTORTION
20
15
10
7
5
INPUT NOISE VOLTAGE
3
2
10
.001
10
100
1K
10K
FREQUENCY, F (Hz)
100K
100
1K
10K
FREQUENCY, F (Hz)
100K
CURRENT LIMIT
.2
CURRENT LIMIT, I
LIM
(A)
.15
PHASE COMPENSATION
0
4
16 20
8
12
24
RESISTOR VALUE, R
CL
(Ω)
.1
.05
GAIN
≥1
≥5
≥10
≥30
C
C
*
68pF
10pF
4.7pF
NONE
R
C
100Ω
100Ω
0Ω
0Ω
0
*C
C
To be rated for the full supply voltage +V
S
to –V
S
.
Use NPO ceramic (COG) type.
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.cirrus.com for design tools
that help automate tasks such as calculations for stability, internal power dissipation, current limit; heat sink selec-
tion; Apex Precision Power’s complete Application Notes library; Technical Seminar Workbook; and Evaluation Kits.
CURRENT LIMIT
For proper operation, the current limit resistor (R
CL
) must be connected as shown in the external connection dia-
gram. For optimum reliability the resistor value should be set as high as possible. The value is calculated as fol-
lows; with the maximum practical value of 32 ohms.
.65
R
CL
=
I
LIM
4
PA90U
®
Product Innovation From
PA90
SAFE OPERATING AREA (SOA)
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 en-
ergy flyback, external fast-recovery diodes should be used.
SAFE OPERATING CURVES
SOA
500
300
200
OUTPUT CURRENT FROM +V
S
OR -V
S
(mA)
The safe operating area curves define the maximum ad-
ditional internal power dissipation the amplifier can toler-
ate when it produces the necessary output to drive an
external load.
20
0m
S
DC
10
0m
S
INPUT PROTECTION
Although the PA90 can withstand differential voltages up
to ±20V, additional external protection is recommended.
Low leakage, low capacitance JFETs connected as di-
odes are recommended (e.g. 2N4416, Q1-Q4 in Fig-
ure 2). The differential input voltage will be clamped to
±1.4V. This is sufficient overdrive to produce maximum
power bandwidth.
100
,T
DC
DC
C
=
,T
25
C
=
°C
85
50
30
20
,T
°C
C
=
12
5°
C
POWER SUPPLY PROTECTION
Unidirectional zener diode transient suppressors are
PULSE CURVES @ 10% DUTY CYCLE MAX.
recommended as protection on the supply pins. See
10
Figure 2. The zeners clamp transients to voltages within
25
75 100 125
250
500
50
the power supply rating and also clamp power supply
SUPPLY TO OUTPUT DIFFERENTIAL, V
S
- V
O
(V)
reversals to ground. Whether the zeners are used or not,
+V
S
the system power supply should be evaluated for transient performance
including power-on overshoot and power-off polarity reversals as well as
Z1
line regulation.
Conditions which can cause open circuits or polarity reversals on either
–IN
1
11, 12
power supply rail should be avoided or protected against. Reversals or
Q1
Q3
6
opens on the negative supply rail is known to induce input stage failure.
PA90
Unidirectional transzorbs prevent this, and it is desirable that they be
Q2
Q4
+IN
both electrically and physically as close to the amplifier as possible.
7, 8
2
STABILITY
The PA90 is externally compensated and performance can be tailored
OVERVOLTAGE
–V
S
to the application. Use the graphs of small signal response and power
PROTECTION
response as a guide. The compensation capacitor C
C
must be rated at 500V working voltage. An NPO capacitor
is recommended. The compensation network C
C
R
C
must be mounted closely to the amplifier pins 4 and 5 to avoid
spurious oscillation.
FIGURE 2.
Z2
QUIESCENT CURRENT REDUCTION
When pin 3 (I
Q
) 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.
PA90U
5
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