
APEX MICROTECHNOLOGY CORPORATION
TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
FEATURES
HIGH VOLTAGE — 400V (
±
200V)
LOW QUIESCENT CURRENT — 10mA
HIGH OUTPUT CURRENT — 200mA
PROGRAMMABLE CURRENT LIMIT
HIGH SLEW RATE — 300V/
μ
s
APPLICATIONS
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 390V
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 operating 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.
External compensation provides flexibility in choosing band-
width and slew rate for the application. APEX’s Power SIP
package uses a minimum of board space allowing for high
density circuit boards.
EQUIVALENT SCHEMATIC
Q1
Q2
R1 R2
C1
R3
Q3
CC1
12
11
+V
S
1
4
5
9
6
10
2
7
8
CC2
3
I
Q
Q6
Q5
R5
R8
R9
Q15
R11
R12
Q16
Q12
Q8
R4
R7
Q4
ILIM
OUT
Q14
R10
Q13
Q11
–
IN
+IN
–
V
S
R6
LOW POWER, PIEZOELECTRIC POSITIONING
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 PA90 reduces
the costs of power supplies and cooling with its advantages of
low cost and low quiescent power consumption while increas-
ing circuit density with the SIP package.
HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX (800) 546-2739
M I C R O T E C H N O L O G Y
HIGH VOLTAGE POWER OPERATIONAL AMPLIFIER
PA90
F
R
PA90
IN
R
1
2
6
7,8
9,10
11,12
PIEZO DRIVE
S
–
V
S
+V
OUT
V
COMPUTER
FOCUS
COMMAND
VOLTAGE
CL
R
PHASE COMPENSATION
EXTERNAL CONNECTIONS
Package: SIP03
GAIN
≥
1
≥
5
≥
10
≥
30
Cc*
68pF
Rc
100
100
0
0
10pF
4.7pF
NONE
*Cc To be rated for the full supply voltage
+V to
–
Vs. Use NPO ceramic (COG) type.
1
2
3
4
5
6
7
8
9
10
–
IN
+IN
R
CL
+Vs
–
Vs
TO LOAD
AND FEEDBACK
11
12
Rc
Cc
*
*
(See text.)
* Bypassing required.
I
Q