Apex PA85, PA85A Datasheet

HIGH VOLTAGE POWER OPERATIONAL AMPLIFIERS

MICROTECHNOLOGY

HTTP://WWW.APEXMICROTECH.COM (800) 546-APEX [phone]

FEA TURES

• HIGH VOLTAGE — 450V (±225V)

• HIGH SLEW RATE — 1000V/µS

• HIGH OUTPUT CURRENT — 200mA

APPLICATIONS

• HIGH VOLTAGE INSTRUMENTATION

• PIEZO TRANSDUCER EXCITATION

• PROGRAMMABLE POWER SUPPLIES UP TO 430V

• ELECTROSTATIC TRANSDUCERS & DEFLECTION

DESCRIPTION

The PA85 is a high voltage, high power bandwidth MOSFET
operational amplifier designed for output currents up to 200mA.
Output voltages can swing up to ±215V with a dual supply and
up to +440 volts with a single supply. 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. All internal biasing is
referenced to a bootstrapped zener-MOSFET current source.
As a result, the PA85 features an unprecedented supply range
and excellent supply rejection. The MOSFET output stage is
biased on for linear operation. External compensation pro­vides user flexibility.

This hybrid circuit utilizes thick film (cermet) resistors, ce­ramic capacitors and silicon semiconductor 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 isolation washers voids the warranty.

EQUIVALENT SCHEMATIC

D1

Q10B

Q4

45

D2

D23

COMP

87

Q11

Q8

Q16

Q9

Q12

Q17

Q1 Q2

Q6 Q7

–IN +IN

Q10A

Q13

PA85 • PA85A

TYPICAL APPLICATION

Dynamic focusing is the active correction of focusing volt­age as a beam traverses the face of a CRT. This is necessary
in high resolution flat face monitors since the distance be­tween cathode and screen varies as the beam moves from the
center of the screen to the edges. PA85 lends itself well to this
function since it can be connected as a summing amplifier with
inputs from the nominal focus potential and the dynamic
correction. The nominal might be derived from a potentiom­eter, or perhaps automatic focusing circuitry might be used to
generate this potential. The dynamic correction is generated
from the sweep voltages by calculating the distance of the
beam from the center of the display.

DC

FOCUS

X SWEEP

SAMPLE

2

CL

3

TOP VIEW

6

COMP

2

2

Q18

z = x + y

Y SWEEP

SAMPLE

3

EXTERNAL CONNECTIONS

+V

S

+Vs

C

L

2

+IN

4

1

OUT

–V

6

S

–IN

5

–Vs

PATENTED

R

IN1

R

IN2

R

CL

1

OUT

COMP

8

7

R

C

R

F

+225V

PA85

–225V

R

CL

PHASE COMPENSATION

Gain C

1 68pF 100Ω

20 10pF 330Ω

100 3.3pF 0Ω

CC RATED FOR FULL

SUPPLY VOLTAGE

C

C

TO
FOCUS
GRID

C

R

C

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P A85 • P A85A

ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

SUPPLY VOLTAGE, +VS to –V
OUTPUT CURRENT, continuous within SOA 200mA

S

450V

POWER DISSIPATION, continuous @ TC = 25°C230W
INPUT VOLTAGE, differential ±25V
INPUT VOLTAGE, common mode ±V
TEMPERATURE, pin solder - 10s max 300°C
TEMPERATURE, junction

2

S

150°C
TEMPERATURE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C

SPECIFICATIONS

PARAMETER TEST CONDITIONS

PA85

1

MIN TYP MAX MIN TYP MAX UNITS

PA85A

INPUT

OFFSET VOLTAGE, initial .5 2 .25 .5 mV
OFFSET VOLTAGE, vs. temperature Full temperature range 10 30 5 10 µV/°C
OFFSET VOLTAGE, vs. supply 3 10 * * µV/V
OFFSET VOLTAGE, vs. time 75 * µV/√kh
BIAS CURRENT, initial
BIAS CURRENT, vs. supply .01 * pA/V
OFFSET CURRENT, initial
INPUT IMPEDANCE, DC 10
INPUT CAPACITANCE 4 * pF
COMMON MODE VOLTAGE RANGE

3

3

4

±VS–12 * V

550 310pA

10 100 3 30 pA

11

* Ω

COMMON MODE REJECTION, DC VCM = ±90V 90 110 * * dB
NOISE 100kHz BW, RS = 1KΩ, CC = 10pf 1 * µVrms

GAIN

OPEN LOOP, @ 15Hz RL = 2KΩ, CC = OPEN 96 111 * * dB
GAIN BANDWIDTH PRODUCT at 1MHz RL = 2KΩ, CC = 3.3pf 100 * MHz
POWER BANDWIDTH CC = 10pf 300 * kHz

CC = 3.3pf 500 * kHz

PHASE MARGIN Full temperature range 60 * °

OUTPUT

VOLTAGE SWING
VOLTAGE SWING
VOLTAGE SWING

4
4
4

IO = ±200mA ±Vs–10 ±Vs–6.5 * * V
IO = ±75mA ±V–8.5 ±Vs–6.0 * * V

IO = ±20mA ±V–8.0 ±Vs–5.5 * * V
CURRENT, continuous TC = 85°C ±200 * mA
SLEW RATE, AV = 20 CC = 10pf 400 * V/µs
SLEW RATE, AV = 100 CC = OPEN 1000 700 * V/µs
CAPACITIVE LOAD, AV = +1 Full temperature range 470 * * pf
SETTLING TIME to .1% CC = 10pf, 2V step 1 * µs
RESISTANCE, no load RCL = 0 50 * Ω

POWER SUPPLY

VOLTAGE

6

Full temperature range ±15 ±150 ±225 * * * V
CURRENT, quiescent 21 25 * * mA

THERMAL

RESISTANCE, AC, junction to case

5

Full temperature range, F > 60Hz 2.5 * °C/W
RESISTANCE, DC, junction to case Full temperature range, F < 60Hz 4.2 * °C/W
RESISTANCE, junction to air Full temperature range 30 * °C/W
TEMPERATURE RANGE, case Meets full range specifications –25 +85 * * °C

NOTES: * The specification of PA85A is identical to the specification for PA85 in applicable column to the left.

1. Unless otherwise noted: TC = 25°C, compensation = CC = 68pF, RC = 100Ω. DC input specifications are ± value given. Power
supply voltage is typical rating.

2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF. Ratings apply only to output transistors. An additional 10W may be dissipated due to quiescent power.

3. Doubles for every 10°C of temperature increase.

4. +VS and –VS denote the positive and negative power supply rail respectively.

5. Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz.

6. Derate max supply rating .625 V/°C below 25°C case. No derating needed above 25°C case.

CAUTION

The PA85 is constructed from MOSFET transistors. ESD handling procedures must be observed.
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.

APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: [phone]

TYPICAL PERFORMANCE
GRAPHS

P A85 • P A85A

40

POWER DERATING

32

24

16

OUTPUT STAGE

8

0

0 25 50 75 100 125 150

INTERNAL POWER DISSIPATION, P(W)

CASE TEMPERATURE, T (°C)

SMALL SIGNAL RESPONSE

120

C

100

C = 3.3pF

80
60

C = 10pF

C

C

40

20

C = 68pF

0

OPEN LOOP GAIN, A (dB)

–20

100 1K 10K .1M 1M

10

C

FREQUENCY, F (Hz)

10M

20M

PHASE RESPONSE

0

–45

–90

Φ

–135

PHASE, (°)

–180

–225
–270

.2M

FREQUENCY F (Hz)

OUTPUT VOLTAGE SWING

10

SO

9

8

7

6

5
4

0

OUTPUT CURRENT, I (mA)

VOLTAGE DROP FROM SUPPLY, V – V (V)

C = 68pF

C

C = 10pF

C

C = 3.3pF

C

1M 10M 40M

C

T = 125°C

T = 25°C

C

T = –55°C

C

100

200

O

250

Q

1.20

QUIESCENT CURRENT

1.15

1.10

C

1.05

1.00

T = 125°C

T = 25°C

C

T = –55°C

C

.95
.90

0 100 300 400

TOTAL SUPPLY VOLTAGE, V (V)

NORMALIZED QUIESCENT CURRENT, I (X)

200

450

S

POWER RESPONSE

500

PP

250

O

125
100

C = 68pf

C

75
50

R = 2K Ω

OUTPUT VOLTAGE, V (V )

L

25

FREQUENCY, F (Hz)

C = 10pf

C

500K

C = 3.3pf

C

1M

5M

2M50K 100K 200K

1000

SLEW RATE

µ

500

200

SLEW RATE, (V/ S)

100

060

30 75

EXT. COMPENSATION CAPACITOR, C (pF)

COMMON MODE REJECTION

140

C = 10pF

C

120

100

80

60

40

20

1K 10K 10M

COMMON MODE REJECTION, CMR (dB)

100K 1M

FREQUENCY, F (Hz)

9015 45 10

C

HARMONIC DISTORTION

.05

AV = 30

.03

P = 15W

O

C = 10pf

C

R = 1KΩ

L

.01

.005
.003

DISTORTION, (%)

INPUT NOISE VOLTAGE

20

√

15

N

10

7
5

3

.001

FREQUENCY, F (Hz)

100K100 1K 10K

2

INPUT NOISE VOLTAGE, V (nV/ Hz)

10 100 10K 100K

FREQUENCY, F (Hz)

POWER SUPPLY REJECTION

140

120

100

80

60

40
20

10 100 1K 10K .1M

11M

POWER SUPPLY REJECTION, PSR (dB)

FREQUENCY, F (Hz)

500

300
200

LIM

100

50

CURRENT LIMIT, I (mA)

20

220

1 5 10 30

RESISTOR VALUE, R ( )

1K

CURRENT LIMIT

Ω

CL

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PA85 • PA85A

GENERAL

Please read the “General Operating Considerations” sec­tion, 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.

CURRENT LIMIT

For proper operation, the current limit resistor (RCL) must be
connected as shown in the external connection diagram. The
minimum value is 1.4 ohm, however for optimum reliability the
resistor value should be set as high as possible. The value is
calculated as follows; with the maximum practical value of 30
ohms.

R

CL

SAFE OPERATING AREA (SOA)

The MOSFET output stage of this power operational ampli­fier has two distinct limitations:

1. The current handling capability of the MOSFET geometry

and the wire bonds.

2. The junction temperature of the output MOSFETs.
NOTE: The output stage is protected against transient flyback.

However, for protection against sustained, high energy flyback,
external fast-recovery diodes should be used.

SAFE OPERATING CURVES

The safe operating area curves define the maximum addi­tional internal power dissipation the amplifier can tolerate
when it produces the necessary output to drive an external
load. This is not the same as the absolute maximum internal

500

.7

=

- .016

I

LIM

OPERATING

CONSIDERATIONS

power dissipation listed elsewhere in the specification since
the quiescent power dissipation is significant compared to the
total.

INPUT PROTECTION

Although the PA85 can withstand differential voltages up to
±25V, additional external protection is recommended. Since
the PA85 is a high speed amplifier, low leakage, low capaci­tance JFETs connected as diodes are recommended (e.g.
2N4416, Q1-Q4 in Figure 2). The differential input voltage will
be clamped to ±1.4V. This is sufficient overdrive to produce
maximum power bandwidth.

POWER SUPPLY PROTECTION

Unidirectional zener diode transient suppressors are recom­mended as protection on the supply pins. The zeners clamp
transients to voltages within the power supply rating and also
clamp power supply reversals to ground. Whether the zeners
are used or not, the system power supply should be evaluated
for transient performance including power-on overshoot and
power-off polarity reversals as well as line regulation.

Conditions which can cause open circuits or polarity rever­sals on either power supply rail should be avoided or protected
against. Reversals or opens on the negative supply rail is
known to induce input stage failure. Unidirectional transzorbs
prevent this, and it is desirable that they be both electrically and
physically as close to the amplifier as possible.

STABILITY

The PA85 is externally compensated and performance can
be tailored to the application. Use the graphs of small signal
response and power response as a guide. The compensation
capacitor C
capacitor is recommended. The compensation network C
must be mounted closely to the amplifier pins 7 and 8 to avoid
spurious oscillation.

must be rated at 500V working voltage. An NPO

C

CRC

DC, T

200mS

DC, T

C

= 125°C

125

100mS

DC, T

C

= 25°C

C

= 85°C

PA85U REV. L JANUARY 1998 © 1998 Apex Microtechnology Corp.

–IN

Q1

Q2

+IN

FIGURE 2
OVERVOLTAGE
PROTECTION

Q3

Q4

+V

S

Z1

3

5

PA85

6

4

Z2

–V

S

300

, (mA)

S

200

OR –V

S

100

50

30

20

OUTPUT CURRENT FROM +V

PULSE CURVES @ 10% DUTY CYCLE MAX

10

25 50 75 100 250 500

SUPPLY TO OUTPUT DIFFERENTIAL, VS –VO (V)

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: [phone]