Datasheet PA19A, PA19 Datasheet (Apex)

VIDEO POWER OPERATIONAL AMPLIFIERS

MICROTECHNOLOGY

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

FEA TURES

• VERY FAST SLEW RATE — 900 V/µs

• POWER MOS TECHNOLOGY — 4A peak rating

• LOW INTERNAL LOSSES — 2V at 2A

• PROTECTED OUTPUT STAGE — Thermal Shutoff

• WIDE SUPPLY RANGE — ±15V TO ±40V

APPLICATIONS

• VIDEO DISTRIBUTION AND AMPLIFICATION

• HIGH SPEED DEFLECTION CIRCUITS

• POWER TRANSDUCERS UP TO 5 MHz

• MODULATION OF RF POWER STAGES

• POWER LED OR LASER DIODE EXCITATION

DESCRIPTION

The PA19 is a high voltage, high current operational ampli­fier optimized to drive a variety of loads from DC through the
video frequency range. Excellent input accuracy is achieved
with a dual monolithic FET input transistor which is cascoded
by two high voltage transistors to provide outstanding com­mon mode characteristics. All internal current and voltage
levels are referenced to a zener diode biased on by a current
source. As a result, the PA19 exhibits superior DC and AC
stability over a wide supply and temperature range.

High speed and freedom from second breakdown is as­sured by a complementary power MOS output stage. For
optimum linearity, especially at low levels, the power MOS
transistors are biased in a class A/B mode. Thermal shutoff
provides full protection against overheating and limits the
heatsink requirements to dissipate the internal power losses
under normal operating conditions. A built-in current limit of

0.5A can be increased with the addition of two external
resistors. Transient inductive load kickback protection is pro­vided by two internal clamping diodes. External phase com­pensation allows the user maximum flexibility in obtaining the
optimum slew rate and gain bandwidth product at all gain
settings. A heatsink of proper rating is recommended.

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 thermal washers and/or improper mount­ing torque will void the product warranty. Please see “General
Operating Considerations”.

PA19 • PA19A

TYPICAL APPLICATION

This fast power driver utilizes the 900V/µs slew rate of the
PA19 and provides a unique interface with a current output
DAC. By using the DAC’s internal 1KΩ feedback resistor,
temperature drift errors are minimized, since the temperature
drift coefficients of the internal current source and the internal
feedback resistor of the DAC are closely matched. Gain of

to IIN is –6.5/mA. The DAC’s internal 1K resistor together

V

OUT

with the external 500Ω and 110Ω form a “tee network” in the
feedback path around the PA19. This effective resistance
equals 6.5KΩ . Therefore the entire circuit can be modeled as

6.5KΩ feedback resistor from output to inverting input and a
5mA current source into the inverting input of the PA19. Now
we see the familiar current to voltage conversion for a DAC
where V

EQUIVALENT SCHEMATIC

3

Q3

8

Q12

5

Q17A

4

6

OUT

Q5

Q23

= –IIN x R

Q4

Q10

Q13

Q17B

FEEDBACK

Q16

Q8

.

Q11

D2

Q20

D1

Q24

Q25

Q1

Q9

Q15

Q2

Q21

Q22

2

Q7

1

Q19

7

TYPICAL

+40V

Ω110

APPLICATION

R

PA19

–40V

CL+

5.6pF

R

CL–

±5mA

1K

DAC

PA19 AS FAST POWER DRIVER

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Ω500

±32.5V

Up to 4A

EXTERNAL CONNECTIONS

R

CL+

+V

+IN

–IN

–V

2

3

4

TOP

VIEW

5

6

OUT

1

C

C

8

7

R

CL–

PHASE COMPENSATION

GAIN

100

1000

10

C

C

330pF

1

22pF

2.2pF
none

P A19 • P A19A

ABSOLUTE MAXIMUM RATINGS

SPECIFICATIONS

ABSOLUTE MAXIMUM RATINGS

SUPPLY VOLTAGE, +VS to –V
OUTPUT CURRENT, within SOA 5A

S

80V

POWER DISSIPATION, internal 78W
INPUT VOLTAGE, differential 40V
INPUT VOLTAGE, common mode ±V
TEMPERATURE, pin solder — 10 sec 300°C
TEMPERATURE, junction

1

S

150°C
TEMPERATURE, storage –65 to 155°C
OPERATING TEMPERATURE RANGE, case –55 to 125°C

SPECIFICATIONS

PARAMETER TEST CONDITIONS

PA19

2

MIN TYP MAX MIN TYP MAX UNITS

PA19A

INPUT

OFFSET VOLTAGE, initial TC = 25°C ±.5 ±3 ±.25 ±.5 mV
OFFSET VOLTAGE, vs. temperature TC = 25°C to +85°C1030510µV/°C
OFFSET VOLTAGE, vs. supply TC = 25°C10*µV/V
OFFSET VOLTAGE, vs. power TC = 25°C to +85°C20*µV/W
BIAS CURRENT, initial TC = 25°C 10 200 5 50 pA
BIAS CURRENT, vs. supply TC = 25°C .01 * pA/V
OFFSET CURRENT, initial TC = 25°C 5 100 3 25 pA
INPUT IMPEDANCE, DC TC = 25°C10

11

*MΩ
INPUT CAPACITANCE TC = 25°C6*pF
COMMON MODE VOLTAGE RANGE3TC = 25°C to +85°C ±VS–15 ±VS–12 * * V
COMMON MODE REJECTION, DC TC = 25°C to +85°C, VCM = ±20V 70 104 * * dB

GAIN

OPEN LOOP GAIN at 10Hz TC = 25°C, RL = 1KΩ 111 * dB
OPEN LOOP GAIN at 10Hz TC = 25°C, RL = 15Ω 74 78 * * dB
GAIN BANDWIDTH PRODUCT at 1MHz TC = 25°C, CC = 2.2pF 100 * MHz
POWER BANDWIDTH, AV = 100 TC = 25°C, CC = 2.2pF 3.5 * MHz
POWER BANDWIDTH, AV = 1 TC = 25°C, CC = 330pF 250 * kHz

OUTPUT

VOLTAGE SWING
VOLTAGE SWING
VOLTAGE SWING

3
3
3

TC = 25°C, IO = 4A ±VS–5 ±VS–4 * * V
TC = 25°C to +85°C, IO = 2A ±VS–3 ±VS–2 * * V

TC = 25°C to +85°C, IO = 78mA ±VS–1 ±VS–.5 * * V
SETTLING TIME to .1% TC = 25°C, 2V step .3 * µs
SETTLING TIME to .01% TC = 25°C, 2V step 1.2 * µs
SLEW RATE, AV = 100 TC = 25°C, CC = 2.2pF 600 900 800 * V/µs
SLEW RATE, AV = 10 TC = 25°C, CC = 22pF 650 * V/µs

POWER SUPPLY

VOLTAGE TC = 25°C to +85°C ±15 ±35 ±40 * * * V
CURRENT, quiescent TC = 25°C 100 120 * * mA

THERMAL

RESISTANCE, AC, junction to case

4

TC = 25°C to +85°C, F > 60Hz 1.2 1.3 * * °C/W
RESISTANCE, DC, junction to case TC = 25°C to +85°C, F < 60Hz 1.6 1.8 * * °C/W
RESISTANCE, junction to air TC = 25°C to +85°C30*°C/W
TEMPERATURE RANGE, case Meets full range specifications –25 +85 * * °C

NOTES: * The specification of PA19A is identical to the specification for PA19 in applicable column to the left.

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

2. The power supply voltage for all specifications is the TYP rating unless noted as a test condition.

3. +VS and –VS denote the positive and negative supply rail respectively. Total VS is measured from +VS to –VS.

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

CAUTION

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

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.

TYPICAL PERFORMANCE
GRAPHS

P A19 • P A19A

80
70
60
50
40
30
20
10

INTERNAL POWER DISSIPATION, P(W)

100

80

(dB)

OL

60

40

OPEN LOOP GAIN, A

–20

1000

800
600

400

POWER DERATING

0

0 25 50 75 100 125

CASE TEMPERATURE, TC (°C)

SMALL SIGNAL RESPONSE

2.2pF

22pF

330pF

20

0

1K 100K

100 100M

10K 1M 10M 5

FREQUENCY, F (Hz)

SLEW RATE VS. COMP.

RL = 15Ω

150

3.5

3.0

(A)

2.5

LIM

2.0

1.5

1.0

CURRENT LIMIT, I

.5

0

4V

3V

2V

1V

VOLTAGE DROP FROM SUPPLY (V)

30
20

(V)

O

10

CURRENT LIMIT

R

CL

= 0.27 Ω

= 1.2

CL

ΩR

R

=

CL

∞

–50 100

–25 25 50 75

0

CASE TEMPERATURE, T

C

OUTPUT VOLTAGE SWING

+V

–V

0

1234

OUTPUT CURRENT, I

(A)

O

PULSE RESPONSE

VIN = ±2V

A

tr = 10ns

RL = 15Ω

(°C)

= 10

V

QUIESCENT CURRENT

(X)

Q

1.6

1.4

1.2

1.0

.8

.6

125

30 60 80

TOTAL SUPPLY VOLTAGE, VS (V)

NORMALIZED QUIESCENT CURRENT, I

POWER RESPONSE

80
58

PP

RL = 15Ω

41

O

30

21

15
11

OUTPUT VOLTAGE, V (V )

| +VS | + | –VS | = 80V

8

100K

200K

30

√

20

(nV/ Hz)

N

15

40 50 70

2M

C

C

= 22pF

4M

C

C

= 330pF

600K

1M

FREQUENCY, F (Hz)

INPUT NOISE

C

C

= 2.2pF

8M

20M

200

100

SLEW RATE, (V/µs)

80

40

24

COMPENSATION CAPACITOR, CC (pF)

COMMON MODE REJECTION

120

100

80

60

40

20

1K 10M

COMMOM MODE REJECTION, CMR (dB)

10

20

6

10K 100K

FREQUENCY, F (Hz)

100

40 200

60

1M

100M

400

0

–10

–20

OUTPUT VOLTAGE, V

–30

–50 0 50 100 150

POWER SUPPLY REJECTION

100

80

60

40

20

0

1K

POWER SUPPLY REJECTION, PSR (dB)

10K 100K 1M 100M

FREQUENCY, F (Hz)

200

TIME, t (ns)

250 300

10M

10

7
5

3

INPUT NOISE VOLTAGE, V

10 100 10K 1M

COMMON MODE VOLTAGE

)

70

P–P

(V

65

CM

60

55

50

45

40

10

COMMON MODE VOLTAGE, V

100 1K 10K 100K 1M

1K

FREQUENCY, F (Hz)

FREQUENCY, F (Hz)

100K

10M

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P A19 • P A19A

(Hz)

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

Q2 (and Q25) limit output current by turning on and removing gate
drive when voltage on pin 2 (pin 7) exceeds .65V differential from the
positive (negative) supply rail. With internal resistors equal to 1.2Ω,
current limits are approximately 0.5A with no external current limit
resistors. With the addition of external resistors current limit will be:

.65V

I

= +.54A

LIM

R

To determine values of external current limit resistors:

CL

RCL =

.65V

I

CL

– .54A

PHASE COMPENSATION

At low gain settings, an external compensation capacitor is required
to insure stability. In addition to the resistive feedback network, roll off
or integrating capacitors must also be considered when determining
gain settings. The capacitance values listed in the external connection
diagram, along with good high frequency layout practice, will insure
stability. Interpolate values for intermediate gain settings.

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.

5.0

(A)

S

4.0

3.5

OR –V

S

3.0

2.5

2.0

1.5

15

OUTPUT CURRENT FROM ±V

INTERNAL VOLTAGE DROP SUPPLY TO OUTPUT VS–VO(V)

20

STEADY STATE

30

25

35

The SOA curves combine the effect of these limits and allow for
internal thermal delays. 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. The following
guidelines may save extensive analytical efforts:

1. Capacitive and inductive loads up to the following maximums are

safe:

±V

S

CAPACITIVE LOAD INDUCTIVE LOAD

40V .1µF 11mH
30V 500µF 24mH
20V 2500µF 75mH
15V ∞ 100mH

t = 300ms

40

TC = 25°C

t = 100ms

50

706080

2. Safe short circuit combinations of voltage and current are limited to
a power level of 100W.

3. The output stage is protected against transient flyback. However,
for protection against sustained, high energy flyback, external fast­recovery diodes should be used.

SUPPLY CURRENT

The PA19 features a class A/B driver stage to charge and discharge
gate capacitance of Q7 and Q19. As these currents approach 0.5A, the
savings of quiescent current over that of a class A driver stage is
considerable. However, supply current drawn by the PA19, even with
no load, varies with slew rate of the output signal as shown below.

400

(mA)

S

300

SUPPLY CURRENT

V

= 60V

OUT

RL = 500

P–P

SINE

Ω

200

100

0

SUPPLY CURRENT, I

30K 100K300K 1M 3M 10M

FREQUENCY, F

OUTPUT LEADS

Keep the output leads as short as possible. In the video frequency
range, even a few inches of wire have significant inductances, raising
the interconnection impedance and limiting the output current slew
rate. Furthermore, the skin effect increases the resistance of heavy
wires at high frequencies. Multistrand Litz Wire is recommended to
carry large video currents with low losses.

THERMAL SHUTDOWN

The thermal protection circuit shuts off the amplifier when the
substrate temperature exceeds approximately 150°C. This allows the
heatsink selection to be based on normal operating conditions while
protecting the amplifier against excessive junction temperature during
temporary fault conditions.

Thermal protection is a fairly slow-acting circuit and therefore does
not protect the amplifier against transient SOA violations (areas
outside of the steady state boundary). It is designed to protect against
short-term fault conditions that result in high power dissipation within
the amplifier. If the conditions that cause thermal shutdown are not
removed, the amplifier will oscillate in and out of shutdown. This will
result in high peak power stresses, destroy signal integrity, and reduce

the reliability of the device.

STABILITY

Due to its large bandwidth, the PA19 is more likely to oscillate than
lower bandwidth power operational amplifiers. To prevent oscillations
a reasonable phrase margin must be maintained by:

1. Selection of the proper phase compensation capacitor. Use the

values given in the table under external connections and interpo­late if necessary. The phase margin can be increased by using a
larger capacitor at the expense of slew rate. Total physical length
(pins of the PA19, capacitor leads plus printed circuit traces) should
be limited to a maximum of 3.5 inches.

2. Keep 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 resistances
can be used with increased phase compensation and/or by bypass­ing the feedback resistor.

3. Connect the case to any AC ground potential.

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]

PA19U REV. H FEBRUARY 1998 © 1998 Apex Microtechnology Corp.