鈥?/div>
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 390V
TYPICAL APPLICATION
R
F
+V
S
DESCRIPTION
The PA92 is a high voltage, low quiescent current MOSFET
operational amplifier designed as a low cost solution for driving
continuous output currents up to 4A and pulse currents up to
7A. 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 bandwidth 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
PA92
6
V
OUT
2
COMPUTER
FOCUS
COMMAND
VOLTAGE
9,10
7,8
R
CL
鈥揤
S
LOW POWER, PIEZOELECTRIC POSITIONING
EQUIVALENT SCHEMATIC
12
11
+V
S
R1 R2
C1
R3
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 PA92 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.
R4
Q4
Q1
Q6
Q5
Q2
5
CC2
Q3
PHASE COMPENSATION
ILIM
9
GAIN
鈮?
鈮?
鈮?
鈮?2
Cc*
150pF
100pF
47pF
10pF
Rc
100鈩?/div>
100鈩?/div>
0鈩?/div>
0鈩?/div>
4
CC1
Q8
Q11
R7
10
6
OUT
1
鈥揑N
R5
R8
R9
R6
Q12
3
I
Q
Q16
Q15
R11
R12
Q13
*Cc Never to be < 10pF. Cc To be rated for the full supply
voltage +V to 鈥揤s. Use ceramic NPO (COG) type.
EXTERNAL CONNECTIONS
Q14
R10
1
2
3
4
5
6
7
8
9
Package: SIP03
10
11
12
2
+IN
Rc
鈥揑N
+IN
Cc
R
CL
鈥揤
S
7
8
*
*
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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