Apex PA95 Datasheet

HIGH VOLTAGE POWER OPERATIONAL AMPLIFIER

F

R

PA95

IN

R

PIEZO DRIVE

S

–V

S

+V

OUT

V

COMPUTER

FOCUS

COMMAND

VOLTAGE

CL

R

1

2

10

8

7

12

MICROTECHNOLOGY

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

FEATURES

• HIGH VOLTAGE — 900V (±450V)

• LOW QUIESCENT CURRENT — 1.6mA

• HIGH OUTPUT CURRENT — 100mA

• PROGRAMMABLE CURRENT LIMIT

APPLICATIONS

• HIGH VOLTAGE INSTRUMENTATION

• PROGRAMMABLE POWER SUPPLIES UP TO ±430V

• MASS SPECTROMETERS

• SEMICONDUCTOR MEASUREMENT EQUIPMENT

DESCRIPTION

The PA95 is a high voltage, MOSFET operational amplifier
designed as a low cost solution for driving continuous output
currents up to 100mA and pulse currents up to 200mA into
capacitive loads. The safe operating area (SOA) has no
second breakdown limitations and can be observed for all load
types by choosing an appropriate current limiting resistor. The
MOSFET output stage is biased AB for linear operation.
External compensation provides flexibility in choosing band­width and slew rate for the application. APEX’s Power SIP04
package uses a minimum of board space allowing for high
density circuit boards.

PA95

PATENT PENDING

TYPICAL APPLICATION

Piezo positioning may be applied to the focusing of seg­mented mirror systems. The composite mirror may be com­posed of hundreds of elements, each requiring focusing under
computer control. In such complex systems the PA95 reduces
the costs of power supplies and cooling with its advantages of
low cost and low quiescent power consumption while increas­ing circuit density with the SIP package.

EQUIVALENT SCHEMATIC

12

+V

S

1

–IN

2

+IN

–V

S

10

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Q1 Q2

Q5

R5

R8

Q15

R11

R1 R2 C1

Q6

CC1

R9

R3

Q3

6

CC2

4

R6

Q8

Q12

Q16

R12

Q11

Q13

R4

R10

R7

Q4
ILIM

OUT

Q14

8

EXTERNAL CONNECTIONS PACKAGE SIP04

7

–IN +IN CC1 CC2 OUT I

12 4 678 10

C

c

*

.01µF or greater ceramic power supply bypassing required.

PHASE COMPENSATION

GAIN

≥10 4.7pF

C

C

.7

R

=

LIM

I

LIM

lim

R

LIM

–Vs +Vs

**

12

PA95

ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

SUPPLY VOLTAGE, +VS to –V
OUTPUT CURRENT, source, sink 200mA, within SOA
POWER DISSIPATION, continuous @ TC = 25°C 30W
INPUT VOLTAGE, differential ±20V
INPUT VOLTAGE, common mode
TEMPERATURE, pin solder - 10s max 220°C
TEMPERATURE, junction
TEMPERATURE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C

S

3

2

900V

±V

S

150°C

SPECIFICATIONS

PARAMETER TEST CONDITIONS
INPUT

OFFSET VOLTAGE, initial .5 5 mV
OFFSET VOLTAGE, vs. temperature Full temperature range 15 50 µV/°C
OFFSET VOLTAGE, vs. supply 10 25 µV/V
OFFSET VOLTAGE, vs. time 75 µV/√kh
BIAS CURRENT, initial 200 2000 pA
BIAS CURRENT, vs. supply 4 pA/V
OFFSET CURRENT, initial 50 500 pA
INPUT IMPEDANCE, DC 10
INPUT CAPACITANCE 4pF
COMMON MODE VOLTAGE RANGE3Vs=±250V SEE NOTE 3 ±VS 30 V
COMMON MODE REJECTION, DC VCM = ±90V 80 98 dB
NOISE 10KHz BW, RS = 1KΩ 2 µVrms

GAIN

OPEN LOOP, @ 15Hz RL = 5KΩ 94 118 dB
GAIN BANDWIDTH PRODUCT at 1MHz RL = 5KΩ 10 MHz
POWER BANDWIDTH RL = 5KΩ 20 kHz
PHASE MARGIN,Av=10 Full temperature range 60 °

OUTPUT

VOLTAGE SWING IO = 100mA ±VS 24 ±VS 20 V
CURRENT, continuous 100 mA
SLEW RATE, AV = 100 CC =4.7pF 30 V/µs
SETTLING TIME to .1% 2V step 1 µs
RESISTANCE no load 100 Ω

POWER SUPPLY

VOLTAGE
CURRENT, quiescent 1.6 2.2 mA

THERMAL

RESISTANCE, AC, junction to case
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 –25 +85 °C

5

See note 5 ±50 ±300 ±450 V

4

Full temperature range, F > 60Hz 2.5 °C/W

1

MIN TYP MAX UNITS

11

Ω

±

±

±

NOTES: 1. Unless otherwise noted: TC = 25°C, DC input specifications are ± value given. Power supply voltage is typical rating. Cc= 4.7pF.

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

2. Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF.

3. Although supply voltages can range up to ± 450V the input pins cannot swing over this range. The input pins must be at least
30V from either supply rail but not more than 500V from either supply rail. See text for a more complete description of the
common mode voltage range.

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

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

CAUTION

The PA95 is constructed from MOSFET transistors. ESD handling procedures must be observed.

TYPICAL PERFORMANCE
GRAPHS

PA95

30

POWER DERATING

25

T = T

20

C

15

10

T = T

5
0

INTERNAL POWER DISSIPATION, P(W)

120

A

0 25 50 75 100 125 150

TEMPERATURE, T (°C)

SMALL SIGNAL RESPONSE

100

80

C = 4.7pF

C

60

40

20

OPEN LOOP GAIN, A (dB)

0

100 1K 10K 100K 1M 10M10

FREQUENCY, F (Hz)

-90

PHASE RESPONSE

-135

-180

-225

-270

PHASE, φ(°)

-315

-360
1M 2M 3M 4M 5M

24

SO

20

16

12

8

4

0

VOLTAGE DROP FROM SUPPLY, V – V (V)

C = 4.7pF

FREQUENCY, F (Hz)

OUTPUT VOLTAGE SWING

°C

C

T = 125

T = 25

T = –55°C

C

20

40

OUTPUT CURRENT, I (mA)

60

C

T = 85

C

80

O

1.08

1.04

1.00

.96

.92

QUIESCENT CURRENT, I(X)

.88

0 200 600 800 1000

TOTAL SUPPLY VOLTAGE, V (V)

400

S

POWER RESPONSE

1K

QUIESCENT CURRENT

°C

°C

100

500

O P-P

C = 4.7pF

200

100

OUTPUT VOLTAGE, V (V )

50

10K

FREQUENCY, F (Hz)

100K 300K

C

200

CURRENT LIMIT

120
100

LIM

70
50

30
20

CURRENT LIMIT, I (mA)

10

550

3 10 20 100

CURRENT LIMIT RESISTOR, R

SAFE OPERATING AREA

250

, (mA)

S

150
100

OR –V

S

50

DC, T

25

DC, T

C

= 125°C

DC, T

C

= 85

100mS

200mS

C

= 25

°C

20

(nV/√Hz)

15

N

10

°C

7
5

INPUT NOISE

15
10

PULSE CURVES @ 10% DUTY CYCLE MAX

5

100

150

( )

Ω

CL

50

SUPPLY TO OUTPUT DIFFERENTIAL, VS –VO (V)

OUTPUT CURRENT FROM +V

200

500 1K

3

2

INPUT NOISE VOLTAGE, V

10 100 10K 1M

1K

FREQUENCY, F (Hz)

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PA95

OPERATING

CONSIDERATIONS

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 (R
connected as shown in the external connection diagram. The
minimum value is 3.5 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 150
ohms.

R

LIM

.7

=

I

LIM

) must be

LIM

COMMON MODE INPUT RANGE

Operational amplifiers are usually designed to have a com­mon mode input voltage range that approximates the power
supply voltage range. However, to keep the cost as low as
possible and still meet the requirements of most applications
the common mode input voltage range of the PA95 is re­stricted. The input pins must always be a least 30V from either
supply voltage but never more than 500V. This means that the
PA95 cannot be used in applications where the supply volt­ages are extremely unbalanced. For example, supply voltages
of +800V and –100V would not be allowed in an application
where the non-inverting pin is grounded because in normal
operation both input pins would be at 0V and the difference
voltage between the positive supply and the input pins would
be 800V. In this kind of application, however,
+500V and -100V does meet the input common mode voltage
range requirements since the maximum difference voltage
between the inputs pins and the supply voltage is 500V (the
maximum allowed). The output has no such restrictions on its
voltage swing. The output can swing within 24V of either supply
voltage regardless of value so long as the total supply voltage

supply voltages

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 reversal 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 PA95 is stable at gains of 10 or more with a NPO (COG)
compensation capacitor of 4.7pF. The compensation capaci­tor, Cc, in the external connections diagram must be rated at
1000V working voltage and mounted closely to pins 4 and 6 to
prevent spurious oscillation. A compensation capacitor less
than 4.7pF is not recommended.

EXTERNAL COMPONENTS

The compensation capacitor Cc must be rated for the total
supply voltage. An NPO (COG)capacitor rated a 1kV is recom­mended.

Of equal importance are the voltage rating and voltage
coefficient of the gain setting feedback resistor. Typical volt­age ratings of low wattage resistors are 150 to 250V. Up to
500 V can appear across the feedback resistor. High voltage
rated resistors can be obtained. However a 1 megohm feed­back resistor composed of five 200k resistors in series will
produce the proper voltage rating.

CAUTIONS

The operating voltages of the PA95 are potentially lethal.
During circuit design develop a functioning circuit at the lowest
possible voltages. Clip test leads should be used for "hands
off" measurements while troubleshooting.

A.

+V

S

Z1

does not exceed 900V.

12

INPUT PROTECTION

–IN

Although the PA95 can withstand differential input voltages
up to ±20V, additional external protection is recommended. In
most applications 1N4148 or 1N914 signal diodes are suffi-

+IN

cient (D1, D2 in Figure 1a). In more demanding applications
where low leakage or low capacitance are of concern 2N4416
or 2N5457-2N5459 JFETs connected as diodes will be re­quired (Q1, Q2 in Figure 1b). In either case the input differential
voltage will be clamped to ±.7V. This is sufficient overdrive to
produce maximum power bandwidth. Note that this protection
does not automatically protect the amplifier from excessive
common mode input voltages.

POWER SUPPLY PROTECTION

Unidirectional zener diode transient suppressors are recom­mended as protection on the supply pins. The zeners clamp

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.

PA95U REV. B DECEMBER 1999 © 1999 Apex Microtechnology Corp.

FIGURE 1. OVERVOLTAGE PROTECTION

1

D2D1

PA95

2

10

+V

Z2

–V

S

B.

–IN

Q1 Q2

+IN

S

Z1

12

1

PA95

2

10

Z2

–V

S