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FEATURES
• WIDE SUPPLY RANGE — ±10 to ±40V
• HIGH OUTPUT CURRENT — ±10A Peak
• SECOND SOURCEABLE — OPA501, 8785
• CLASS “C” OUTPUT — Low Cost
• LOW QUIESCENT CURRENT — 2.6mA
APPLICATIONS
• DC SERVO AMPLIFIER
• MOTOR/SYNCHRO DRIVER
• VALVE AND ACTUATOR CONTROL
• DC OR AC POWER REGULATOR
DESCRIPTION
The PA51 and PA51A are high voltage, high output current
operational amplifiers designed to drive resistive, inductive
and capacitive loads. Their complementary common emitter
output stage is the simple class C type optimized for low fre-
quency applications where crossover distortion is not critical.
These amplifiers are not recommended for audio, transducer
or deflection coil drive circuits. The safe operating area (SOA)
is fully specified and can be observed for all operating con-
ditions by selection of user programmable current limiting
resistors. Both amplifiers are internally compensated for all
gain settings. For continuous operation under load, mounting
on a heatsink of proper rating is recommended. Do not use
isolation washers!
This hybrid integrated circuit utilizes thick film conductors,
ceramic capacitors and semiconductor chips to maximize reli-
ability, minimize size and give top performance. Ultrasonically
bonded aluminum wires provide reliable interconnections at
all operating temperatures. The 8-pin TO-3 package is electri-
cally isolated and hermetically sealed. The use of compress-
ible thermal washers and/or improper mounting torque will
void the product warranty. Please see “General Operating
Considerations”.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATION
The linear relationship of torque output to current input of
the modern torque motor makes this simple control circuit
ideal for many material processing and testing applications.
The sense resistor develops a feedback voltage proportional
to motor current and the small signal properties of the Power
Op Amp insure accuracy. With this closed loop operation,
temperature induced impedance variations of the motor wind-
ing are automatically compensated.
EXTERNAL CONNECTIONS
8-PIN TO-3
PACKAGE STYLE CE
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
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ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
PA51 PA51A
PARAMETER TEST CONDITIONS 2, 5 MIN TYP MAX MIN TYP MAX UNITS
INPUT
OFFSET VOLTAGE, initial TC = 25°C ±5 ±10 ±2 ±5 mV
OFFSET VOLTAGE, vs. temperature Full temperature range ±10 ±65 * ±40 µV/°C
OFFSET VOLTAGE, vs. supply TC = 25°C ±35 * µV/V
OFFSET VOLTAGE, vs. power TC = 25°C ±20 * µV/W
BIAS CURRENT, initial TC = 25°C ±15 ±40 * ±20 nA
BIAS CURRENT, vs. temperature Full temperature range ±.05 * nA/°C
BIAS CURRENT, vs. supply TC = 25°C ±.02 * nA/V
OFFSET CURRENT, initial TC = 25°C ±5 ±12 ±2 ±3 nA
OFFSET CURRENT, vs. temperature Full temperature range ±.01 * nA/°C
INPUT IMPEDANCE, common mode TC = 25°C 250 * MΩ
INPUT IMPEDANCE, differential TC = 25°C 10 * MΩ
INPUT CAPACITANCE TC = 25°C 3 * pF
COMMON MODE VOLTAGE RANGE3 Full temperature range ±VS–6 ±VS–3 * * V
COMMON MODE REJECTION, DC3 TC = 25°C, VCM = ±VS –6V 70 110 80 * dB
GAIN
OPEN LOOP GAIN at 10Hz Full temp. range, full load 94 115 * * dB
GAIN BANDWIDTH PRODUCT @ 1MHz TC = 25°C, full load 1 * MHz
POWER BANDWIDTH TC = 25°C, IO = 8A, VO = 40VPP 10 16 * * kHz
PHASE MARGIN Full temperature range 45 * °
OUTPUT
VOLTAGE SWING3 TC = 25°C, IO = 10A ±VS–8 ±VS–5 * * V
VOLTAGE SWING3 Full temp. range, IO = 4A ±VS–6 ±VS–4 * * V
VOLTAGE SWING3 Full temp. range, IO = 68mA ±VS–6 * V
CURRENT TC = 25°C ±10 * A
SETTLING TIME to .1% TC = 25°C, 2V step 2 * µs
SLEW RATE TC = 25°C, RL = 6Ω 1.0 2.6 * * V/µs
CAPACITIVE LOAD, unity gain Full temperature range 1.5 * nF
CAPACITIVE LOAD, gain > 4 Full temperature range SOA *
POWER SUPPLY
VOLTAGE Full temperature range ±10 ±28 ±36 * ±34 ±40 V
CURRENT, quiescent TC = 25°C 2.6 10 * * mA
THERMAL
RESISTANCE, AC, junction to case4 F > 60Hz 1.0 1.2 * * °C/W
RESISTANCE, DC, junction to case F < 60Hz 1.5 1.8 * * °C/W
RESISTANCE, junction to air 30 * °C/W
TEMPERATURE RANGE, case Meets full range specifications –25 +85 –55 +125 °C
PA51 • PA51A
SUPPLY VOLTAGE, +VS to –VS 80V
OUTPUT CURRENT, within SOA 10A
POWER DISSIPATION, internal 97W
INPUT VOLTAGE, differential ±VS –3V
INPUT VOLTAGE, common mode ±VS
TEMPERATURE, junction1 200°C
TEMPERATURE, pin solder -10s 300°C
TEMPERATURE RANGE, storage –65 to +150°C
OPERATING TEMPERATURE RANGE, case –55 to +125°C
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
NOTES: * The specification of PA51A is identical to the specification for PA51 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 specified under the TYP rating applies unless otherwise 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.
5. Full temperature range specifications are guaranteed but not 100% tested.
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
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TYPICAL PERFORMANCE
GRAPHS PA51 • PA51A
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
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OPERATING
CONSIDERATIONS
PA51 • PA51A
GENERAL
Please read Application Note 1 "General Operating Con-
siderations" which covers stability, supplies, heat sinking,
mounting, current limit, SOA interpretation, and specification
interpretation. Visit www.apexmicrotech.com for design tools
that help automate tasks such as calculations for stability, in-
ternal 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 output stage of most power amplifiers has three distinct
limitations:
1. The current handling capability of the transistor geometry
and the wire bonds.
2. The second breakdown effect which occurs whenever the
simultaneous collector current and collector-emitter voltage
exceeds specified limits.
3. The junction temperature of the output transistors.
The SOA curves combine the effect of of all limits for this
Power Op Amp. For a given application, the direction and
magnitude of the output current should be calculated or mea-
sured 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. Under transient conditions, capacitive and dynamic* induc-
tive loads up to the following maximums are safe:
CAPACITIVE LOAD INDUCTIVE LOAD
±VS ILIM = 5A ILIM = 10A ILIM = 5A ILIM = 10A
40V 400µF 200µF 11mH 4.3mH
35V 800µF 400µF 20mH 5.0mH
30V 1,600µF 800µF 35mH 6.2mH
25V 5.0mF 2.5mF 50mH 15mH
20V 10mF 5.0mF 400mH 20mH
15V 20mF 10mF ** 100mH
* If the inductive load is driven near steady state conditions,
allowing the output voltage to drop more than 8V below the
supply rail with ILIM = 10A or 15V below the supply rail with
ILIM = 5A while the amplifier is current limiting, the inductor
should be capacitively coupled or the current limit must be
lowered to meet SOA criteria.
** Second breakdown effect imposes no limitation but thermal
limitations must still be observed.
2. The amplifier can handle any EMF generating or reactive
load and short circuits to the supply rail or shorts to common
if the current limits are set as follows at TC = 85°C.
SHORT TO ±VS SHORT TO
±VS C, L, OR EMF LOAD COMMON
45V 0.1A 1.3A
40V 0.2A 1.5A
35V 0.3A 1.6A
30V 0.5A 2.0A
25V 1.2A 2.4A
20V 1.5A 3.0A
15V 2.0A 4.0A
These simplified limits may be exceeded with further analysis
using the operating conditions for a specific application.
3.The output stage is protected against transient flyback. How-
ever, for protection against sustained, high energy flyback,
external fast-recovery diodes should be used.
CURRENT LIMIT
Proper operation requires the use of two current limit resis-
tors, connected as shown in the external connection diagram.
The minimum value for RCL is .06 ohm, however for optimum
reliability it should be set as high as possible. Refer to the
“General Operating Considerations” section of the handbook
for current limit adjust details.
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.
PA51U REV M FEBRUARY 2003 © 2003 Apex Microtechnology Corp.
