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1
EXTERNAL CONNECTION
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”.
TOP VIEW
1
2
3
4
5
678
–V
S
+IN
–IN
BAL
COMP
OUT
BAL +V
S
NOTES:
1. Phase Compensation required
for safe operation.
2. Input offset trimpot optional.
Recommended value 100K .
Ω
R
C
C
C
PHASE COMPENSATION
GAIN
1
10
100
1000
C
C
10nF
500pF
50pF
none
R
C
200
2K
20K
none
Ω
Ω
Ω
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
*Not included in PA84S.
+150V
–150V
100K
PA84
±10V
50K
INK JET
CONTROL
10K
DAC
......
......
......
4.7K
390pF
HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX (800) 546-2739
MICROTECHNOLOGY
POWER OPERATIONAL AMPLIFIERS
PA84 • PA84A • PA84S
2
7
4
3
5
6
1
Q1 Q2
D1
D2
Q15
Q12B
Q9
C4
Q8
Q13
Q4
Q3
C1
Q16 Q17
Q5
C5
Q12A
Q14
C6
Q10
Q6
Q7
Q11
8
*
*
*
*
*
*
8-pin TO-3
PACKAGE STYLE CE
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
2
NOTES: * The specification of PA84A is identical to the specification for PA84/PA84S in applicable column to the left.
1. Signal slew rates at pins 5 and 6 must be limited to less than 1V/ns to avoid damage. When faster waveforms are unavoidable,
resistors in series with those pins, limiting current to 150mA will protect the amplifier from damage.
2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF.
3. The power supply voltage for all tests is ±150V, unless otherwise noted as a test condition.
4. Doubles for every 10°C of temperature increase.
5. +VS and –VS denote the positive and negative power supply rail respectively.
6. Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz.
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS SUPPLY VOLTAGE, +VS to –VS300V
OUTPUT CURRENT, within SOA Internally Limited
POWER DISSIPATION, internal at TC = 25°C217.5W
INPUT VOLTAGE, differential PA84/PA84A1±300V
INPUT VOLTAGE, differential PA84S ±50V
INPUT VOLTAGE, common mode1±VS
TEMPERATURE, pins for 10s max (solder) 300°C
TEMPERATURE, junction2200°C
TEMPERATURE RANGE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C
PA84 • PA84A • PA84S
The internal substrate contains beryllia (BeO). Do not break the seal. If accidentally broken, do not crush, machine, or
subject to temperatures in excess of 850°C to avoid generating toxic fumes.
CAUTION
PARAMETER TEST CONDITIONS3MIN TYP MAX MIN TYP MAX UNITS
INPUT
OFFSET VOLTAGE, initial TC = 25°C±1.5 ±3±.5 ±1mV
OFFSET VOLTAGE, vs. temperature TC = –25° to +85°C±10 ±25 ±5±10 µV/°C
OFFSET VOLTAGE, vs. supply TC = 25°C±.5 ±.2 µV/V
OFFSET VOLTAGE, vs. time TC = 25°C±75 * µV/√kh
BIAS CURRENT, initial4TC = 25°C550310pA
BIAS CURRENT, vs. supply TC = 25°C.01 * pA/V
OFFSET CURRENT, initial4TC = 25°C±2.5 ±50 ±1.5 ±10 pA
OFFSET CURRENT, vs. supply TC = 25°C±.01 * pA/V
INPUT IMPEDANCE, DC TC = 25°C10
11 *Ω
INPUT CAPACITANCE TC = –25° to +85°C6*pF
COMMON MODE VOLTAGE RANGE5TC = –25° to +85°C±VS–10 ±VS–8.5 * * V
COMMON MODE REJECTION, DC TC = –25° to +85°C130 * dB
GAIN
OPEN LOOP GAIN at 10Hz TC = 25°C, RL = ∞120 * dB
OPEN LOOP GAIN at 10Hz. TC = 25°C, RL = 3.5KΩ100 118 * * dB
GAIN BANDWIDTH PRODUCT@ 1MHz TC = 25°C, RL = 3.5KΩ, RC = 20KΩ75 * MHz
POWER BANDWIDTH, high gain TC = 25°C, RL = 3.5KΩ, RC = 20KΩ250 180 * kHz
POWER BANDWIDTH, low gain TC = 25°C, RL = 3.5KΩ, RC = 20KΩ120 * kHz
OUTPUT
VOLTAGE SWING5TC = 25°C, IO = ±40mA ±VS–7 ±VS–3 * * V
VOLTAGE SWING5TC = –25° to +85°C, IO = ±15mA ±VS–5 ±VS–2 * * V
CURRENT, peak TC = 25°C40*mA
CURRENT, short circuit TC = 25°C50*mA
SLEW RATE, high gain TC = 25°C, RL = 3.5KΩ, RC = 20KΩ200 150 * V/µs
SLEW RATE, low gain TC = 25°C, RL = 3.5KΩ, RC = 2KΩ125 * V/µs
SETTLING TIME .01% at gain = 100 TC = 25°C, RL = 3.5KΩ PA84S 2µs
SETTLING TIME .1% at gain = 100 RC = 20KΩ, VIN = 2V step
ONLY 1µs
SETTLING TIME .01% at gain = 100 TC = 25°C, RL = 3.5KΩ PA84/84A 20 20 µs
SETTLING TIME .1% at gain = 100 RC = 20KΩ, VIN = 2V step 12 12 µs
POWER SUPPLY
VOLTAGE TC = –55°C to +125°C±15 ±150 * * V
CURRENT, quiescent TC = 25°C5.5 7.5 * * mA
THERMAL
RESISTANCE, AC, junction to case6TC = –55°C to +125°C, F > 60Hz 3.8 * °C/W
RESISTANCE, DC, junction to case TC = –55°C to +125°C, F < 60Hz 6 6.5 * * °C/W
RESISTANCE, case to air TC = –55°C to +125°C30*°C/W
TEMPERATURE RANGE, case Meets full range specifications –25 +85 * * °C
SPECIFICATIONS PA84A
PA84/PA84S
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
3
TYPICAL PERFORMANCE
GRAPHS PA84 • PA84A • PA84S
0255075100 125
TEMPERATURE, T
C
(°C)
5
20
30
POWER DERATING
INTERNAL POWER DISSIPATION, P(W)
–55 100
30
70
80
CURRENT LIMIT
50
FREQUENCY, F (Hz)
INPUT NOISE VOLTAGE, V
N
(nV/ Hz)
1FREQUENCY, F (Hz)
–20
0
60
SMALL SIGNAL RESPONSE
OPEN LOOP GAIN, A
OL
(dB)
20
40
80
100
10
1.5
2.5
4.0
5.0
OUTPUT VOLTAGE SWING
3.5
4.5
FREQUENCY, F (Hz)
OUTPUT VOLTAGE, V (V )
O
SLEW RATE VS. COMP
SLEW RATE (V/µS)
200
TOTAL SUPPLY VOLTAGE, V
S
(V)
.4
.6
1.6
SLEW RATE VS. SUPPLY
NORMALIZED SLEW RATE (X)
.8
1.4
COMMON MODE VOLTAGE
COMMON MODE VOLTAGE, V
CM
(V
PP
)
1FREQUENCY, F (Hz)
COMMON MODE REJECTION
COMMON MODE REJECTION, CMR (dB)
40
80
120
10 100 1FREQUENCY, F (Hz)
POWER SUPPLY REJECTION
POWER SUPPLY REJECTION, PSR (dB)
0 150 250
2
OPEN LOOP GAIN
CURRENT LIMIT, I
LIM
(mA)
0
INPUT NOISE
√
–25 25 50 75
60
25
POWER RESPONSE
PP
3050 100 150
1.2
50 100 200
–8
–6
1K .1M
VOLTAGE DROP SUPPLY, V
S
–V
O
(V)
RELATIVE OPEN LOOP GAIN, A(dB)
–4
20
60
100
10 100
20
40
60
80
100
1.0
40
4
2.0
3.0
0125
20 30 40 50
250 300
15
10
0
10K 1M 10M
FREQUENCY, F (Hz)
0
300
120
10010 60 70
OUTPUT CURRENT, I
O
(mA)
140
1K 10K 1M 1K 10K 1M
120
140
200
70
30
20
50
150
100
1K 5K 20K2K
200 500 10K
.1M .1M
30
50
100
200
300
15
1M
10K .1M
20K 50K .2M .5M
2
3
5
10
20
15
7
10 1K 10K .1M
100
CASE TEMPERATURE, T
C
(°C) TOTAL SUPPLY VOLTAGE, V
S
(V)
–2
15
100
1M
.1M
50K .2M .5M
30
60
200
300
.3M .7M
150 20
150
150
EXT. COMPENSATION RESISTANCE, R
C
( )
Ω
T
C
= 85°C
T
C
= 25°C
T
C
= –25°C
R
L
= 3.5KΩ
R
C
/C
C
= 20K /50pF
Ω
R
C
/C
C
= 2K /500pFΩ
R
C
/C
C
= 200 /10nFΩ
ΩR
L
= 3.5K
T
C
= 85°C
T
C
= 25°C
T
C
= –25°C
R
L
= 3.5K R
L
= 3.5K
R
C
/C
C
= 200 /10nF
Ω
V
S
= ±150V
V
S
= ±150V
Ω
R
C
/
C
C
=
2
0
K
/
5
0
p
F
Ω
R
C
/
C
C
=
2
K
/
5
0
0
p
F
ΩΩ
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
4
OPERATING
CONSIDERATIONS
PA84 • PA84A • PA84S
GENERAL
Please read Application Note 1 "General Operating Consid-
erations" which covers stability, supplies, heat sinking, mount-
ing, current limit, SOA interpretation, and specification inter-
pretation. Visit www.apexmicrotech.com for design tools that
help automate tasks such as calculations for stability, internal
power dissipation, current limit and heat sink selection. The
"Application Notes" and "Technical Seminar" sections contain
a wealth of information on specific types of applications.
Package outlines, heat sinks, mounting hardware and other
accessories are located in the "Packages and Accessories"
section. Evaluation Kits are available for most Apex product
models, consult the "Evaluation Kit" section for details. For the
most current version of all Apex product data sheets, visit
www.apexmicrotech.com.
SAFE OPERATING AREA (SOA)
The bipolar output stage of this high voltage operational
amplifier has two output limitations:
1. The internal current limit which limits maximum available
output current.
2. The second breakdown effect, which occurs whenever the
simultaneous collector current and collector-emitter voltage
exceeds specified limits.
The SOA curves combine the effect of these limits. For a
given application, the direction and magnitude of the output
current should be calculated or measured and checked against
the SOA curves. This is simple for resistive loads but more
complex for reactive and EMF generating loads. However, the
following guidelines may save extensive analytical efforts:
1. The following capacitive and inductive loads are safe:
±VSC(MAX) L(MAX)
150V 1.2µF.7H
125V 6.0µF 25H
100V 12µF 90H
75V ALL ALL
2. Short circuits to ground are safe with dual supplies up to
±150V or single supplies up to 150V.
3. Short circuits to the supply rails are safe with total supply
voltages up to 150V (i.e. ±75V).
STABILITY
Due to its large bandwidth the PA84 is more likely to oscillate
than lower bandwidth Power Operational Amplifiers such as
the PA83 or PA08. To prevent oscillations, a reasonable phase
margin must be maintained by:
1. Selection of the proper phase compensation capacitor and
resistor. Use the values given in the table under external
connections and interpolate if necessary. The phase mar-
gin can be increased by using a large capacitor and a
smaller resistor than the slew rate optimized values listed in
the table. The compensation capacitor may be connected to
common (in lieu of +VS) if the positive supply is properly
bypassed to common. Because the voltage at pin 8 is only
a few volts below the positive supply, this ground connec-
tion requires the use of a high voltage capacitor.
2. Keeping the external sumpoint stray capacitance to ground
at a minimum and the sumpoint load resistance (input and
feedback resistors in parallel) below 500Ω. Larger sumpoint
load resistance can be used with increased phase compen-
sation (see 1 above).
3. Connecting the amplifier case to a local AC common thus
preventing it from acting as an antenna.
+V
S
–V
S
FIGURE 1. PROTECTIVE,
INDUCTIVE LOAD
20
30
40
50
25
35
300
200 250
150 170
SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE (V)
OUTPUT CURRENT FROM +V
S
OR –V
S
(mA)
t = 5ms
t = 1ms
SAFE OPERATING AREA CURVES
STEADY STATE
OUTPUT PROTECTION
Two external diodes as shown in Figure 1, are required to
protect these amplifiers against flyback (kickback) pulses
exceeding the supply voltages of the amplifier when driving
inductive loads. For component selection, these external
diodes must be very quick, such as ultra fast recovery diodes
with no more than 200 nanoseconds of reverse recovery time.
Be sure the diode voltage rating is greater than the total of both
supplies. The diode will turn on to divert the flyback energy into
the supply rails thus protecting the output transistors from
destruction due to reverse bias.
A note of caution about the supply. The energy of the flyback
pulse must be absorbed by the power supply. As a result, a
transient will be superimposed on the supply voltage, the
magnitude of the transient being a function of its transient
impedance and current sinking capability. If the supply voltage
plus transient exceeds the maximum supply rating or if the AC
impedance of the supply is unknown, it is best to clamp the
output and the supply with a zener diode to absorb the
transient.
This data sheet has been carefully checked and is believed to be reliable, however, no responsibility is assumed for possible inaccuracies or omissions. All specifications are subject to change without notice.
PA84U REV. M AUGUST 2002 © 2002 Apex Microtechnology Corp.
