鈥?/div>
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 390V
TYPICAL APPLICATION
R
F
+V
S
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鈥檚 Power SIP
package uses a minimum of board space allowing for high
density circuit boards.
R
IN
1
11,12
PIEZO DRIVE
PA90
6
V
OUT
2
COMPUTER
FOCUS
COMMAND
VOLTAGE
9,10
7,8
R
CL
鈥揤
S
LOW POWER, PIEZOELECTRIC POSITIONING
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.
EQUIVALENT SCHEMATIC
12
11
+V
S
R1 R2
C1
R3
Q1
Q6
Q5
Q2
5
CC2
Q3
R4
Q4
ILIM
9
Q8
Q11
R7
10
6
OUT
Q12
3
I
Q
Q16
Q13
PHASE COMPENSATION
GAIN
鈮?
鈮?
鈮?0
鈮?0
Cc*
68pF
10pF
4.7pF
NONE
Rc
100鈩?/div>
100鈩?/div>
0鈩?/div>
0鈩?/div>
4
CC1
1
鈥揑N
R5
R8
R9
R6
*Cc To be rated for the full supply voltage
+V to 鈥揤s. Use NPO ceramic (COG) type.
EXTERNAL CONNECTIONS
Q14
R10
1
2
3
4
5
6
7
8
9
Package: SIP03
10
11
12
2
+IN
Q15
Rc
Cc
R
CL
R11
鈥揤
S
7
8
R12
鈥揑N
+IN
*
*
鈥揤s
+Vs
I
Q
(See text.)
TO LOAD
AND FEEDBACK
* Bypassing required.
APEX MICROTECHNOLOGY CORPORATION
鈥?TELEPHONE (520) 690-8600 鈥?FAX (520) 888-3329 鈥?ORDERS (520) 690-8601 鈥?EMAIL prodlit@apexmicrotech.com
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