鈥?/div>
PIEZOELECTRIC POSITIONING
HIGH VOLTAGE INSTRUMENTATION
ELECTROSTATIC TRANSDUCERS
PROGRAMMABLE POWER SUPPLIES UP TO 390V
TYPICAL APPLICATION
R
F
+V
S
DESCRIPTION
The PA93 is a high voltage, low quiescent current MOSFET
operational amplifier designed as a low cost solution for driving
continuous output currents up to 8A and pulse currents up to
14A. The safe operating area (SOA) has no second break-
down 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 com-
pensation 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
PA93
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 PA93 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?
鈮?7
Cc*
220pF
100pF
47pF
10pF
Rc
100鈩?/div>
100鈩?/div>
0鈩?/div>
0鈩?/div>
4
CC1
1
鈥揑N
R5
R8
R9
R6
*Cc Never to be < 10pF. Cc To be rated for the full supply
voltage +V to 鈥揤s. Use ceramic NPO (COG) type.
2
+IN
Q15
R11
鈥揤
S
7
8
Q14
R10
EXTERNAL CONNECTIONS
1
2
3
4
5
6
7
8
9
Package: SIP03
10
11
12
R12
鈥揑N
+IN
Rc
Cc
R
CL
*
*
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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