鈥?/div>
HIGH VOLTAGE INSTRUMENTATION
PROGRAMMABLE POWER SUPPLIES UP TO
鹵430V
MASS SPECTROMETERS
SEMICONDUCTOR MEASUREMENT EQUIPMENT
PATENT PENDING
DESCRIPTION
The PA94 is a high voltage, MOSFET operational amplifier
designed as a low cost solution for driving continuous output
currents up to 100mA and pulse currents up to 200mA into
capacitive loads. The safe operating area (SOA) has no
second breakdown limitations and can be observed for all load
types 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 SIP04
package uses a minimum of board space allowing for high
density circuit boards.
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 PA94 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.
R
F
+V
S
EQUIVALENT SCHEMATIC
12
+V
S
R1 R2
C1
R3
R
IN
1
12
PIEZO DRIVE
PA94
7
V
OUT
Q1
Q6
Q5
Q2
6
CC2
Q3
R4
Q4
ILIM
8
Q8
Q11
R7
2
COMPUTER
FOCUS
COMMAND
VOLTAGE
8
10
R
CL
4
CC1
鈥揤
S
EXTERNAL CONNECTIONS
7
OUT
PACKAGE SIP04
1
鈥揑N
R5
R8
R9
R6
Q12
Q13
鈥揑N
1
+IN
2
CC1
4
CC2 OUT I
lim
6
7
8
鈥揤s
10
+Vs
12
2
+IN
Q15
Q16
Q14
R10
C
c
R
LIM
*
*
*
.01碌F or greater ceramic power supply bypassing required.
R11
鈥揤
S
10
R12
PHASE COMPENSATION
GAIN
鈮?00
鈮?0
鈮?0
C
C
2.2pF
4.7pF
22pF
.7
R
LIM
=
I
LIM
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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