PA84 Datasheet, PDF (1/4 Pages) Cirrus Logic – POWER OPERATIONAL AMPLIFIERS

MICROTECHNOLOGY
POWER OPERATIONAL AMPLIFIERS
PA84 • PA84A • PA84S
HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX [phone]
FEATURES
• HIGH SLEW RATE — 200V/µs
• FAST SETTLING TIME — .1% in 1µs (PA84S)
• FULLY PROTECTED INPUT — Up to ±150v
• LOW BIAS CURRENT, LOW NOISE — FET Input
• WIDE SUPPLY RANGE — ±15V to ±150V
APPLICATIONS
• HIGH VOLTAGE INSTRUMENTATION
• ELECTROSTATIC TRANSDUCERS & DEFLECTION
• PROGRAMMABLE POWER SUPPLIES UP TO 290V
• ANALOG SIMULATORS
DESCRIPTION
The PA84 is a high voltage operational amplifier designed for
output voltage swings up to ±145V with a dual supply or 290V
with a single supply. Two versions are available. The new
PA84S, fast settling amplifier can absorb differential input over-
voltages up to ±50V while the established PA84 and PA84A can
handle differential input overvoltages of up to ±300V. Both
versions are protected against common mode transients and
overvoltages up to the supply rails. High accuracy is achieved
with a cascode input circuit configuration. All internal biasing is
referenced to a zener diode fed by a FET constant current
source. As a result, the PA84 features an unprecedented supply
range and excellent supply rejection. The output stage is biased-
on for linear operation. External phase compensation allows for
user flexibility in obtaining the maximum slew rate. Fixed current
limits protect these amplifiers against shorts to common at
supply voltages up to 150V. For operation into inductive loads,
two external flyback pulse protection diodes are recommended.
However, a heatsink may be necessary to maintain the proper
case temperature under normal operating conditions.
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 8-
pin TO-3 package is hermetically sealed and electrically
isolated. The use of compressible thermal isolation washers
and/or improper mounting torque will void the product war-
ranty. Please see “General Operating Considerations”.
EXTERNAL CONNECTION
BAL
3
+V_S
2
1 OUT
4
C_C
BAL
TOP VIEW
5
–IN
6
+IN
R_C
8
7
COMP
–V_S
PHASE COMPENSATION
GAIN
1
10
100
1000
C_C
10nF
500pF
50pF
none
R_C
200 Ω
2K Ω
20K Ω
none
NOTES:
1. Phase Compensation required
for safe operation.
2. Input offset trimpot optional.
Recommended value 100K Ω .
100K 50K
+150V
4.7K
±10V
DAC
10K
390pF
PA84
INK JET
CONTROL
..................
–150V
TYPICAL APPLICATION
The PA84 is ideally suited to driving ink jet control units
(often a piezo electric device) which require precise pulse
shape control to deposit crisp clear date or lot code information
on product containers. The external compensation network
has been optimized to match the gain setting of the circuit and
the complex impedance of the ink jet control unit. The combi-
nation of speed and high voltage capabilities of the PA84 form
ink droplets of uniform volume at high production rates to
enhance the value of the printer.
EQUIVALENT SCHEMATIC
4
2
3
Q1
Q5
8
Q8
C5 _*
C4
5
Q12A
*
Q13 _*
Q14 _*
6
*
Q15
C6 _*
7
C1
D1
Q3
Q2
Q4
Q9
Q10
Q11
Q12B
Q6
Q7
1
Q17
Q16
D2
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