APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
FEATURES
WIDE SUPPLY RANGE --
10 to
45V
HIGH OUTPUT CURRENT --
10A Peak
LOW COST -- Class "C" output stage
LOW QUIESCENT CURRENT -- 3mA
APPLICATIONS
PROGRAMMABLE POWER SUPPLY
MOTOR/SYNCRO DRIVER
VALVE AND ACTUATOR CONTROL
DC OR AC POWER REGULATOR
FIXED FREQUENCY POWER OSCILLATOR
DESCRIPTION
The PA61 and PA61A are high output current operational
amplifiers designed to drive resistive, inductive and capacitive
loads. Their complementary emitter follower output stage is
the simple class C type and optimized for low frequency
applications where crossover distortion is not critical. These
amplifiers are not recommended for audio, transducer or
deflection coil drive circuits above 1kHz or when distortion is
critical. The safe operating area (SOA) is fully specified and
can be observed for all operating conditions by selection of
user programmable current limiting resistors. Both amplifiers
are internally compensated for all gain settings. For continu-
ous operation under load, mounting on a heatsink of proper
rating is recommended.
This hybrid circuit utilizes thick film conductors, ceramic
capacitors, and 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 electri-
cally isolated and hermetically sealed. The use of compres-
sible thermal washers and/or improper mounting torque voids
the product warranty. Please see "General Operating Consid-
erations".
EQUIVALENT SCHEMATIC
TOP VIEW
1
2
3
4
5
6
7
8
C
L
V
S
+IN
IN
+V
S
OUT
N.C.
C
L+
R
CL+
R
CL
OUTPUT
+42V
42V
R
F1
PA61
R
CL+
R
CL
R
F2
R
W
RTN
SENSE LO
R
W
10V
SENSE HI
LOAD
DAC
R
IN1
R
IN2
OUT
FIGURE 1. PROGRAMMABLE POWER SUPPLY
WITH REMOTE SENSING
2
8
1
3
6
4
5
A1
Q3
Q4
C1
Q1A
Q1B
Q6B
Q6A
TYPICAL APPLICATION
Due to its high current drive capability, PA61 applications
often utilize remote sensing to compensate IR drops in the
wiring. The importance of remote sensing increases as accu-
racy requirements, output currents, and distance between
amplifier and load go up. The circuit above shows wire
resistance from the PA61 to the load and back to the local
ground via the power return line. Without remote sensing, a
7.5A load current across only 0.05 ohm in each line would
produce a 0.75V error at the load.
With the addition of the second ratio matched R
F
/R
IN
pair and
two low current sense wires, IR drops in the power return line
become common mode voltages for which the op amp has a
very high rejection ratio. Voltage drops in the output and power
return wires are inside the feedback loop. Therefore, as long
as the Power Op Amp has the voltage drive capability to
overcome the IR losses, accuracy remains the same. Applica-
tion Note 7 presents a general discussion of PPS circuits.
EXTERNAL CONNECTIONS
H T T P : / / W W W . A P E X M I C R O T E C H . C O M ( 8 0 0 ) 5 4 6 - A P E X ( 8 0 0 ) 5 4 6 - 2 7 3 9
M I C R O T E C H N O L O G Y
POWER OPERATIONAL AMPLIFIERS
PA61 PA61A
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
PARAMETER
TEST CONDITIONS
2
MIN
TYP
MAX
MIN
TYP
MAX
UNITS
INPUT
OFFSET VOLTAGE, initial
T
C
= 25
C
2
6
1
3
mV
OFFSET VOLTAGE, vs. temperature
Specified temperature range
10
65
*
40
V/
C
OFFSET VOLTAGE, vs. supply
T
C
= 25
C
30
200
*
*
V/V
OFFSET VOLTAGE, vs. power
T
C
= 25
C
20
*
V/W
BIAS CURRENT, initial
T
C
= 25
C
12
30
10
20
nA
BIAS CURRENT, vs. temperature
Specified temperature range
50
500
*
*
pA/
C
BIAS CURRENT, vs. supply
T
C
= 25
C
10
*
pA/V
OFFSET CURRENT, initial
T
C
= 25
C
12
30
5
10
nA
OFFSET CURRENT, vs. temperature
Specified temperature range
50
*
pA/
C
INPUT IMPEDANCE, DC
T
C
= 25
C
200
*
M
INPUT CAPACITANCE
T
C
= 25
C
3
*
pF
COMMON MODE VOLTAGE RANGE
3
Specified temperature range
V
S
5
V
S
3
*
*
V
COMMON MODE REJECTION, DC
3
Specified temperature range
74
100
*
*
dB
GAIN
OPEN LOOP GAIN at 10Hz
Full temp. range, full load
96
108
*
*
dB
GAIN BANDWIDTH PRODUCT at 1MHz T
C
= 25
C, full load
1
*
MHz
POWER BANDWIDTH
T
C
= 25
C, I
O
= 8A, V
O
= 40V
PP
10
16
*
*
kHz
PHASE MARGIN
Full temperature range
45
*
OUTPUT
VOLTAGE SWING
3
T
C
= 25
C, I
O
= 10A
V
S
7
V
S
5
V
S
6
*
V
VOLTAGE SWING
3
Full temp. range, I
O
= 4A
V
S
6
V
S
4
*
*
V
VOLTAGE SWING
3
Full temp. range, I
O
= 68mA
V
S
5
*
V
CURRENT
T
C
= 25
C
10
*
A
SETTLING TIME to .1%
T
C
= 25
C, 2V step
2
*
s
SLEW RATE
T
C
= 25
C, R
L
= 6
1.0
2.8
*
*
V/
s
CAPACITIVE LOAD, unit gain
Full temperature range
1.5
*
nF
CAPACITIVE LOAD, gain>4
Full temperature range
SOA
*
POWER SUPPLY
VOLTAGE
Full temperature range
10
32
45
*
*
*
V
CURRENT, quiescent
T
C
= 25
C
3
10
*
*
mA
THERMAL
RESISTANCE, AC, junction to case
4
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 specification
25
25
+85
*
*
*
C
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
SPECIFICATIONS
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, +V
S
to V
S
90V
OUTPUT CURRENT, within SOA
10A
POWER DISSIPATION, internal
97W
INPUT VOLTAGE, differential
V
S
3V
INPUT VOLTAGE, common mode
V
S
TEMPERATURE, pin solder-10s
300
C
TEMPERATURE, junction
1
200
C
TEMPERATURE RANGE, storage
65 to +150
C
OPERATING TEMPERATURE RANGE, case
55 to +125
C
PA61A
PA61
PA61 PA61A
NOTES:
*
The specification of PA61A is identical to the specification for PA61 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.
+V
S
and V
S
denote the positive and negative supply rail respectively. Total V
S
is measured from +V
S
to V
S
.
4.
Rating applies if the output current alternates between both output transistors at a rate faster than 60Hz.
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
APEX MICROTECHNOLOGY CORPORATION TELEPHONE (520) 690-8600 FAX (520) 888-3329 ORDERS (520) 690-8601 EMAIL prodlit@apexmicrotech.com
TYPICAL PERFORMANCE
GRAPHS
PA61 PA61A
0
25
50
75
100
125
150
TEMPERATURE, T (C)
0
20
60
100
POWER DERATING
INTERNAL POWER DISSIPATION, P (W)
50
0
100
.7
1.9
2.2
BIAS CURRENT
1.3
.4
10
100
10K
.1M
FREQUENCY, F (Hz)
INPUT NOISE VOLTAGE, V (nV/ Hz)
1
100
10M
FREQUENCY, F (Hz)
20
0
60
120
SMALL SIGNAL RESPONSE
OPEN LOOP GAIN, A
OL
(dB)
20
40
80
100
1
100
.1M
10M
210
150
60
0
PHASE RESPONSE
90
30
FREQUENCY, F (Hz)
OUTPUT VOLTAGE, V (V )
O
FREQUENCY, F (Hz)
HARMONIC DISTORTION
DISTORTION, (%)
40
TOTAL SUPPLY VOLTAGE, V
S
(V)
.4
.6
1.6
QUIESCENT CURRENT
NORMALIZED QUIESCENT CURRENT
, I
Q
(X)
.8
1.4
1
10K
FREQUENCY, F (Hz)
0
COMMON MODE REJECTION
COMMON MODE REJECTION, CMR(dB)
40
80
120
.1M
10
100
25
50
100
CASE TEMPERATURE, T (C)
0
6
CURRENT LIMIT
CURRENT LIMIT, I (A)
LIM
5
C
INPUT NOISE
1K
10
20
30
N
1K
25
25
50
75
1.6
40
POWER RESPONSE
PP
50
60
70
80
90
1.2
0
25
75
2
3
10
1K
10K .1M 1M
80
10
10K
1M
FREQUENCY, F (Hz)
PHASE, (
)
NORMALIZED BIAS CURRENT, I
B
(X)
1
4
1K
1M
20
60
100
1.0
125
1.0
125
7
CASE TEMPERATURE, T (C)
C
180
120
40
50
70
100
2.5
C
30
20
0
OUTPUT CURRENT, I
O
(A)
OUTPUT VOLTAGE SWING
VOLTAGE DROP FROM SUPPLY (V)
3.0
2
4
6
8
10
3.5
4.0
4.5
5.0
5.5
2.5
0
TIME, t (s)
PULSE RESPONSE
OUTPUT VOLTAGE, V (V)
8
2
4
6
8
10
12
6
4
2
0
2
4
6
8
O
14
R
CL
= .12
R
CL
= 0.3
T
C
= 25
to 85
C
T
C
=
25
C
T = T
C
21
30
41
58
15
80
11
10K
.1M
20K
30K
50K 70K
8
R
L
= 8
R
L
= 3
V
S
= 40V
R
L
= 5
A
V
= +1
1
3
10
.3
.1
30
300
1K
10K
100
30K
.03
.01
3K
V
S
= 36
R
L
= 4
A
V
= 10
P
O
= 5W
P
O
= .1W
P
O
= 50W
T
C
=
55
C
T
C
= 25C
T
C
= 125C
APEX MICROTECHNOLOGY CORPORATION 5980 NORTH SHANNON ROAD TUCSON, ARIZONA 85741 USA APPLICATIONS HOTLINE: 1 (800) 546-2739
OPERATING
CONSIDERATIONS
PA61 PA61A
GENERAL
Please read Application Note 1 "General Operating Consid-
erations" which covers stability, supplies, heat sinking, mount-
ing, current limit, SOA interpretation, and specification inter-
pretation. Visit www.apexmicrotech.com for design tools that
help automate tasks such as calculations for stability, internal
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 3 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 all limits for this Power
Op Amp. 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. Under transient conditions, capacitive and dynamic* induc-
tive loads up to the following maximum are safe:
CAPACITIVE LOAD
INDUCTIVE LOAD
V
S
I
LIM
= 5A I
LIM
= 10A
I
LIM
= 5A
I
LIM
= 10A
45V 200 F 150 F
8mH
2.8mH
40V 400 F 200 F
11mH
4.3mH
35V 800 F 400 F
20mH
5.0mH
30V 1600 F 800 F
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 I
LIM
= 10A or 15V below the supply rail with
I
LIM
= 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 T
C
=85
C.
SHORT TO V
S
SHORT TO
V
S
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 analy-
sis using the operating conditions for a specific application.
3. The output stage is protected against transient flyback.
However, for protection against sustained, high energy
flyback, external fast-recovery diodes should be used.
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.
PA61U REV. H JANUARY 2001
2001 Apex Microtechnology Corp.
Tc=125
C
Tc=85C
Steady State
t=5
ms
t=1
m
s
t=0.5ms
10
20
30
SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE V
S
V
O
(V)
SAFE OPERATING AREA (SOA)
INPUT CURRENT FROM +V
S
OR
V
S
(A)
40
50
60
70
90
80
.1
.2
.3
.4
.6
.8
1.0
2.0
3.0
4.0
6.0
8.0
10
1.5
Tc=25
C
25
15
PDF 
ZIP