peak swings across a piezo element. A high gain of 鈥?0 for A1
insures stability with the capacitive load, while 鈥渘oise-gain鈥?/div>
compensation Rn and Cn on A2 insure the stability of A2 by
operating in a noise gain of 50.
50R
50R
50R
+600V
R
V
IN
A1
PA89
PIEZO
TRANSDUCER
鈥?00V
鈥?00V
A2
PA89
+600V
R
DESCRIPTION
The PA89 is an ultra high voltage, MOSFET operational
amplifier designed for output currents up to 75 mA. Output
voltages can swing over 1000V p-p. The safe operating area
(SOA) has no second breakdown limitations and can be
observed with all types of loads by choosing an appropriate
current limiting resistor. High accuracy is achieved with a
cascode input circuit configuration and 120dB open loop gain.
All internal biasing is referenced to a bootstrapped zener-
MOSFET current source, giving the PA89 a wide supply range
and excellent supply rejection. The MOSFET output stage is
biased for class A/B linear operation. External compensation
provides user flexibility. The PA89 is 100% gross leak tested
to military standards for long term reliability.
This hybrid integrated circuit utilizes a beryllia (BeO) sub-
strate, thick film resistors, ceramic capacitors and semicon-
ductor chips to maximize reliability, minimize size and give top
performance. Ultrasonically bonded aluminum wires provide
reliable interconnections at all operating temperatures. The
MO-127 High Voltage, Power Dip鈩?package is hermetically
sealed and electrically isolated.
Cn
SINGLE AXIS MICRO-POSITIONING
EXTERNAL CONNECTIONS*
鈥揑N
+IN
N/C
1
2
3
4
5
12
11
TOP
VIEW
10
9
8
7
RESERVED
RESERVED
C
C
COMP
R
C
+V
S
C
L
R
CL
=
.7
I
LIM
COMP
SIMPLIFIED SCHEMATIC
D1
Q5
Q1
Q2
D57
COMP
9 10
鈥揑N
1
Q22
Q25A
Q23
Q25B
+IN
2
Q19
Q20
Q26
C
L
7
8
+V
S
N/C
鈥揤
S
OUT
6
Q29
Q36
6
OUT
R
CL
PHASE COMPENSATION
Gain
1
10
15
100
C
C
470pF
68pF
33pF
15pF
R
C
470鈩?/div>
220鈩?/div>
220鈩?/div>
220鈩?/div>
D30
D35
Q45
D34
D31
Q44
D5
Q42
鈥揤
S
5
Note: C
C
must be rated for full supply voltage 鈥揤s to +Vs.
See details under 鈥淓XTERNAL COMPONENTS鈥?
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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