The PA80 series of high voltage operation amplifiers provides an extremely wide range of supply capability with two
overlapping products. High accuracy is achieved with a cascode
input circuit configuration. All internal biasing is referenced to
a zener diode. As a result, these models offer outstanding
common mode and power supply rejection. The output stage
operates in the class A/B mode for best linearity. Internal
phase compensation assures stability at all gain settings
without external components. Fixed internal current limits
protect these amplifiers against a short circuit to common at
most supply voltages. For sustained high energy flyback,
external fast recovery diodes should be used. However, a
heatsink may be necessary to maintain the proper case
temperature under normal operating conditions.
This hybrid circuit utilizes thick film resistors, ceramic capacitors and silicon semiconductors 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 (see Package
Outlines) is hermetically sealed and isolated from the internal
circuits. The use of compressible thermal washers voids the
warranty.
The PA81 and 70K ohm resistor form a current to voltage
converter, accepting ±1mA from a 12 bit current output digital
to analog converter. The power op amp contribution to the
error budget is insignificant. At a case temperature of 70°C,
the combination of voltage offset and bias errors amounts to
less than 31ppm of full scale range. Incorporation of the
optional offset trim can further reduce these errors to under
9ppm.
EQUIVALENT SCHEMATIC
EXTERNAL CONNECTIONS
+V
3
TOP VIEW
6
–V
S
2
1
8
7
N.C.
S
BAL
BAL
4
–IN
5
+IN
NOTE: Input offset trimpot optional.
Recommended value of 100K .
SUPPLY VOLTAGE, +VS to –V
OUTPUT CURRENT, within SOAInternally Limited
S
200V 300V
POWER DISSIPATION, internal11.5W 11.5W
INPUT VOLTAGE, differential±150V±300V
INPUT VOLTAGE, common mode±V
TEMPERATURE, pin solder - 10 sec300°C 300°C
S
±V
S
TEMPERATURE, junction150°C 150°C
TEMPERATURE RANGE, storage–65 to +125°C –65 to +125°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C –55 to +125°C
SPECIFICATIONS
PARAMETERTEST CONDITIONS
PA81J
2
MINTYPMAXMINTYPMAXUNITS
PA82J
INPUT
OFFSET VOLTAGE, initialTC = 25°C±1.5±3**mV
OFFSET VOLTAGE, vs. temperatureFull temperature range1025**µV/°C
OFFSET VOLTAGE, vs. supplyTC = 25°C20*µV/V
OFFSET VOLTAGE, vs. timeTC = 25°C75*µV/√kh
BIAS CURRENT, initialTC = 25°C550**pA
BIAS CURRENT, vs. supplyTC = 25°C.2*pA/V
OFFSET CURRENT, initialTC = 25°C2.550**pA
INPUT IMPEDANCE, DCTC = 25°C10
11
*Ω
INPUT CAPACITANCETC = 25°C10*pF
COMMON MODE VOLTAGE RANGE2Full temperature range±VS–10*V
COMMON MODE REJECTION, DCVCM = ±20V110*dB
GAIN
OPEN LOOP GAIN at 10HzFull load94116100118dB
UNITY GAIN BANDWIDTHTC = 25°C5*MHz
POWER BANDWIDTHTC = 25°C, full load6030kHz
PHASE MARGINFull temperature range45*°
OUTPUT
VOLTAGE SWING
CURRENT, peakTC = 25°C3015mA
2
TC = 25°C, I
PK
±VS–5* V
CURRENT, limitTC = 25°C5025mA
SETTLING TIME to .1%TC = 25°C, 10V step12*µs
SLEW RATE
4
TC = 25°C20*V/µs
CAPACITIVE LOADAV = 110*nF
POWER SUPPLY
VOLTAGEFull temperature range±32±75±75±70±150±150V
CURRENT, quiescentTC = 25°C6.58.56.58.5mA
THERMAL
RESISTANCE, AC, junction to case
RESISTANCE, DC, junction to case
3
F > 60Hz6*°C/W
3
F < 60Hz910**°C/W
RESISTANCE, junction to airFull temperature range30*°C/W
TEMPERATURE RANGE, shutdown150*°C
TEMPERATURE RANGE, caseMeets full range specification070**°C
NOTES: *The specification of PA82J is identical to the specification for PA81J in applicable column to the left.
1.The power supply voltage for all specifications is the TYP rating unless noted as a test condition.
2.+VS and –VS denote the positive and negative supply rail respectively. Total VS is measured from +VS to –VS.
3.Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz.
4.On the PA81J and PA82J, 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.
CAUTION
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
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.
Please read Application Note 1 , which covers stability,
supplies, heatsinking, mounting, current limit, SOA interpretation, and specification interpretation. Additional information
can be found in the application notes. For information on the
package outline, heatsinks, and mounting hardware, consult
the “Accessory and Package Mechanical Data” section of the
handbook.
SAFE OPERATING AREA (SOA)
For the PA80J and PA81J, the combination of voltage
capability and internal current limits mandate that the devices
are safe for all combinations of supply voltage and load. On the
PA82J, any load combination is safe up to a total supply of 250
volts. When total supply voltage equals 300 volts, the device
will be safe if the output current is limited to 10 milliamps or less.
This means that the PA82J used on supplies up to 125 volts will
sustain a short to common or either supply without danger.
When using supplies above ±125 volts, a short to one of the
supplies will be potentially destructive. When using single
supply above 250 volts, a short to common will be potentially
destructive.
Safe supply voltages do not imply disregard for heatsinking.
The thermal calculations and the use of a heatsink are required
in many applications to maintain the case temperature within
the specified operating range of 0 to 70°C. Exceeding this case
temperature range can result in an inoperative circuit due to
excessive input errors or activation of the thermal shutdown.
+V
S
OPERATING
CONSIDERATIONS
SINGLE SUPPLY OPERATION
These amplifiers are suitable for operation from a single
supply voltage. The operating requirements do however, impose the limitation that the input voltages do not approach
closer than 10 volts to either supply rail. This is due to the
operating voltage requirements of the current sources, the
half-dynamic loads and the cascode stage. Refer to the
simplified schematics.Thus, single supply operation requires
the input signals to be biased at least 10 volts from either
supply rail. Figure 3 illustrates one bias technique to achieve
this.
50K
2.5/10V
D/A
FIGURE 3.
TRUE SINGLE
SUPPLY OPERATION
2.5K
+210V
50K
2.5K
50K
+210V
PA82J
50K
Figure 4 illustrates a very common deviation from true single
supply operation. The availibility of two supplies still allows
ground (common) referenced signals, but also maximizes the
high voltage capability of the unipolar output. This technique
can utilize an existing low voltage system power supply and
does not place large current demands on that supply. The 12
volt supply in this case must supply only the quiescent current
of the PA81J, which is 8.5mA maximum. If the load is reactive
or EMF producing, the low voltage supply must also be able to
absorb the reverse currents generated by the load.
+210V
+50/+200V
FIGURE 2.
PROTECTION,
INDUCTIVE LOAD
–V
S
INDUCTIVE LOADS
Two external diodes as shown in Figure 2, are required to
protect these amplifiers against flyback (kickback) pulses
exceeding the supply voltage 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.
0/5V
FIGURE 4.
NON-SYMMETRIC
SUPPLIES
D/A
2K
50K
+12V
PA81J
0/–125V
–130V
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.
APEX MICROTECHNOLOGY CORPORATION• 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739