ETC PA28

POWER DUAL OPERATIONAL AMPLIFIERS
PA28/29 • PA28A/29A
M I C R O T E C H N O L O G Y
HTTP://WWW.APEXMICROTECH.COM
(800) 546-APEX
(800) 546-2739
FEATURES
• LOW COST
• WIDE COMMON MODE RANGE —
Includes negative supply
• WIDE SUPPLY VOLTAGE RANGE
Single supply: 5V to 40V–to 44V,A Grade
Split supplies: ±2.5V to ±20V–to ± 22V,A Grade
• HIGH EFFICIENCY — |Vs–2.2V| at 2.5A typ
• HIGH OUTPUT CURRENT — 2.5A min,
3.5A min for A grade
• LOW DISTORTION
M
+
1/2 PA28
R5
10K
R6
10K
COMMAND
INPUT
0/10V
FIGURE 1: BIDIRECTIONAL SPEED CONTROL FROM
A SINGLE SUPPLY
The amplifiers are especially well-suited for this application.
The extended common mode range allows command inputs
as low as 0V. Its superior output swing abilities let it drive within
2V of supply at an output current of 2A. This means that a
command input that ranges from 0V to 10V will drive a 24V
motor from full scale CCW to full scale CW at up to ±2A. A
single power op amp with an output swing capability of Vs –6
would require ±30V supplies and would be required to swing
48V p-p at twice the speed to deliver an equivalent drive.
EXTERNAL CONNECTIONS
PA29
–
PA28
7
8
9
10
VBOOST/+VS
11
12
–IN B
6
OUT B
5
OUT, B
1
B
+
TOP VIEW
–VS 6
4
+
A
5
OUT, A
3
+
–
ISENSE/–VS
2
B
SUB
–VS
1
+VS
2
+IN, A
3
–IN, A
4
+
A
–
+IN B
Connect pins
3 and 10 to pin 7
and connect pins
4 and 9 to pin 6
unless special
functions are required.
+VS
R1 and R2 set up amplifier A in a non-inverting gain of 2.8.
Amp B is set up as a unity gain inverter driven from the output
of amp A. Note that amp B inverts signals about the reference
node, which is set at mid-supply (14V) by R5 and R6. When the
command input is 5V, the output of amp A is 14V. Since this is
equal to the reference node voltage, the output of amp B is also
14V, resulting in 0V across the motor. Inputs more positive
than 5V result in motor current flow from left to right (see Figure
1). Inputs less positive than 5V drive the motor in the opposite
direction.
A
OUT A
TYPICAL APPLICATION
10K
–
B
+
1/2 PA28
–
5K
+28V
10K
ISENSE/–VS
The amplifiers consist of a monolithic dual power op amp
in a 8-pin hermetic TO-3 package (PA28) and a 12-pin SIP
package (PA29). Putting two power op amps in one package
and on one die results in an extremely cost effective solution
for applications requiring multiple amplifiers per board or
bridge mode configurations.
The wide common mode input range includes the negative
rail, facilitating single supply applications. It is possible to
have a “ground based” input driving a single supply amplifier
with ground acting as the “second” or “bottom” supply of the
amplifier.
This hybrid integrated circuit utilizes semiconductor chips
to maximize reliability, minimize size and give top performance. Ultrasonically bonded aluminum wires provide reliable interconnections at all operating temperatures. The 8pin TO-3 package is hermetically sealed and electrically
isolated. The use of compressible isolation washers voids the
warranty. The tab of the SIP12 plastic package is tied to –VS.
R4
–IN A
DESCRIPTION
9K
+28V
VBOOST/+VS
• HALF & FULL BRIDGE MOTOR DRIVERS
• AUDIO POWER AMPLIFIER
STEREO — 18W RMS per channel
BRIDGE — 36W RMS per package
• IDEAL FOR SINGLE SUPPLY SYSTEMS
5V — Peripherals
12V — Automotive
28V — Avionic
R1
R3
+IN A
APPLICATIONS
R2
7
+IN, B
–
8
–IN, B
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected]
ABSOLUTE MAXIMUM RATINGS
SPECIFICATIONS
PA28/29 • PA28A/29A
ABSOLUTE MAXIMUM RATINGS
SUPPLY VOLTAGE, total
OUTPUT CURRENT
POWER DISSIPATION, internal (per amplifier)
POWER DISSIPATION, internal (both amplifiers)
INPUT VOLTAGE, differential
INPUT VOLTAGE, common mode
JUNCTION TEMPERATURE, max1
TEMPERATURE, pin solder—10 sec max
TEMPERATURE RANGE, storage
OPERATING TEMPERATURE RANGE, case
SPECIFICATIONS
PA28/29
TEST CONDITIONS 2
PARAMETER
5V to 44V
SOA
54W
60W
±VS
+VS, -VS–.5V
150°C
300°C
–65°C to 150°C
–55°C to 125°C
MIN
PA28A/29A
TYP
MAX
5
15
35
12
MIN
TYP
MAX
UNITS
1.5
*
*
10
*
*
*
mV
µV/°C
nA
V
dB
dB
dB
*
*
*
*
*
dB
kHz
°
kHz
3.5
*
*
*
4.0
*
*
*
A
V/µs
V
V
V
V
uf
INPUT
OFFSET VOLTAGE, initial
OFFSET VOLTAGE, vs. temperature
BIAS CURRENT, initial
COMMON MODE RANGE
COMMON MODE REJECTION, DC
POWER SUPPLY REJECTION
CHANNEL SEPARATION
Full temperature range
Full temperature range
Full temperature range
Full temperature range
IOUT = 1A, F = 1kHz
–VS–.3
60
60
50
Full temperature range
AV = 40dB
Full temperature range
VO(P-P) = 28V
80
1000
+VS–2
85
80
68
*
*
*
*
*
*
GAIN
OPEN LOOP GAIN
GAIN BANDWIDTH PRODUCT
PHASE MARGIN
POWER BANDWIDTH
100
600
65
15
OUTPUT
CURRENT, peak
SLEW RATE
VOLTAGE SWING
VOLTAGE SWING
VOLTAGE SWING
VOLTAGE SWING
CAPACITIVE LOAD DRIVE
Full temp. range, IO = 95mA
Full temp. range, IO = 1A
IO = 2.5A
IO = 3.5A
Av = 1
2.5
.5
1.5
|VS| –1.0 |VS| –0.8
|VS| –1.8 |VS| –1.0
|VS| –3.0 |VS| –2.0
10
22nf
54
30
30
|VS| –3.5 |VS| –2.5
*
POWER SUPPLY
VOLTAGE, VSS3
CURRENT, quiescent, total
40
90
*
*
*
44
*
V
mA
85
°C/W
°C/W
°C/W
°C/W
°C/W
°C
THERMAL
RESISTANCE, junction to case
DC, single amplifier
DC, both amplifiers4
AC, single amplifier
AC, both amplifiers4
RESISTANCE, junction to air
TEMPERATURE RANGE, case
NOTES:
*
1.
2.
3.
4.
CAUTION
2.3
2.1
1.7
1.6
30
Meets full range specifications
–25
*
*
*
85
–25
The specification of PA28A or PA29A is identical to the specification for PA28 or PA29 in applicable column to the left.
Long term operation at the maximum junction temperature will result in reduced product life. Derate internal power dissipation
to achieve high MTTF.
Unless otherwise noted, the following conditions apply: ±VS = ±15V, TC = 25°C.
+VS and –VS denote the positive and negative supply rail respectively. VSS denotes the total rail-to-rail supply voltage.
Rating applies when power dissipation is equal in the two amplifiers.
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: 1 (800) 546-2739
PA28/29 • PA28A/29A
POWER DERATING
BIAS CURRENT
70
60
BOTH
AMPLIFIERS
40
30
SINGLE
AMPLIFIER
20
10
0
0
25
50
75 100 125 150
TEMPERATURE, T (°C)
80
1.5
75
1.25
1.0
.75
.5
SMALL SIGNAL RESPONSE
0
1
O
–120
–150
10
100 1K 10K 100K 1M
FREQUENCY, F (Hz)
–210
0
POWER SUPPLY REJECTION
10
100 1K 10K .1M
FREQUENCY, F (Hz)
40
30
25
20
15
10
|+VS | + |–VS | = 40V
5
1K
1M
10K
FREQUENCY, F (Hz)
100K
AV = 1
R L =10 Ω
10
86
83
80
77
74
71
5
0
–5
69
66
63
–10
0
10 100 1K 10K 100K 1M
FREQUENCY, F (Hz)
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
10
100
1K
FREQUENCY, F(Hz)
10K
30K
200
400
600
TIME, t (µs)
800
1K
QUIESCENT CURRENT
45
125
40
100
35
75
30
50
25
20
25
15
0
10
-25
5
0.5
0.7
0.9
1.1
1.3
1.5
NORMALIZED QUIESCENT CURRENT
-50
1.7
CASE TEMPERATURE, Tc(°C)
TOTAL SUPPLY VOLTAGE, Vss(V)
HARMONIC DISTORTION
0
VOLTAGE DROP FROM SUPPLY,(V)
60
10K 20K
PULSE RESPONSE
89
OUTPUT VOLTAGE, V O(V)
POWER SUPPLY REJECTION, PSR (dB)
–90
–180
–20
TOTAL HARMONIC DISTORTION, THD(%)
OUTPUT VOLTAGE, V
PHASE, ϕ (°)
OPEN LOOP GAIN, A (dB)
20
1K
100
FREQUENCY, F (Hz)
POWER RESPONSE
–60
40
AMP 2
I OUT = 0
AV = –100
60
50
–30
60
65
PHASE RESPONSE
0
80
70
50
10
.25
–50 –25 0 25 50 75 100 125
CASE TEMPERATURE, T C(°C)
100
AMP 1
I OUT = 1A
AV = –100
55
(V PP)
50
CROSSTALK
1.75
CROSSTALK (dB)
40
NORMALIZED BIAS CURRENT, I B (X)
INTERNAL POWER DISSIPATION, P(W)
TYPICAL PERFORMANCE
GRAPHS
OUTPUT VOLTAGE SWING
1.5
1.25
1
.75
.5
0
0.5
1
1.5
2
2.5
3
3.5
OUTPUT CURRENT, Io (A)
APEX MICROTECHNOLOGY CORPORATION • TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL [email protected]
OPERATING
CONSIDERATIONS
PA28/29 • PA28A/29A
GENERAL
THERMAL CONSIDERATIONS
Please read Application Note 1 "General Operating Considerations" 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, 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.
Although R θJC is the same for PA28/29 there are differences
in the thermal interface between case and heatsink which will
limit power dissipation capability. Thermal grease or an Apex
TW03 thermal washer, R θCS = .1-.2°C/W, is the only recommended interface for the PA28. The PA29 may require a
thermal washer which is electrically insulating since the tab is
tied to –VS. This can result in thermal impedances for R θCS of
up to 1°C/W or greater.
ADDITIONAL PA29 PIN FUNCTIONS
VBOOST
+VS
5
4
s
1m
ED
AD
ED
LO
AD
NE
LO
H
,O
OT
CH
,B
EA
CH
EA
OUTPUT CURRENT, Io(A)
SOA
3
2
– IN
+IN
OUT
ISENSE
RS
1
1
2
3
4
5
10
20
– VS
30 40
SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE, Vs – Vo(V)
FIGURE 2. PA29 EQUIVALENT SCHEMATIC (ONE CHANNEL)
VBOOST
SAFE OPERATING AREA (SOA)
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.
NOTE: For protection against sustained, high energy flyback,
external fast-recovery diodes should be used.
The VBOOST pin is the positive terminal for the load of the
second stage of the amplifier. When that terminal is connected
to a voltage greater than +VS it will provide more drive to the
upper output transistor, which is a darlington connected emitter follower. This will better saturate the output transistor.
When VBOOST is about 5 Volts greater than +VS the positive
output can swing 0.5 Volts closer to the rail. This is as much
improvement as is possible.
VBOOST pin requires approximately 4-6mA of current. Dynamically it represents 1K Ω impedance. The maximum voltage that can be applied to VBOOST is 40 volts with respect to –
VS . There is no limit to the difference between +VS and VBOOST.
MONOLITHIC AMPLIFIER
STABILITY CONSIDERATIONS
All monolithic power op amps use output stage topologies
that present special stability problems. This is primarily due to
non-complementary (both devices are NPN) output stages
with a mismatch in gain and phase response for different
polarities of output current. It is difficult for the op amp manufacturer to optimize compensation for all operating conditions.
The recommended R-C network of 1 ohm in series with
0.1µF from output to AC common (ground or a supply rail, with
adequate bypass capacitors) will prevent local output stage
oscillations.
APEX MICROTECHNOLOGY CORPORATION • 5980 NORTH SHANNON ROAD • TUCSON, ARIZONA 85741 • USA • APPLICATIONS HOTLINE: 1 (800) 546-2739
PA28/29 • PA28A/29A
OPERATING
CONSIDERATIONS
+VS ≤ 20V
DB1
+VS
DB2
PA29
7
3
10
CB1
PA29A
5
VREF
CB2
PA29B
SPEAKER
B
R
RL
VIN
IL
R
A
RFB
8
RIN
FIGURE 3. SIMPLE BOOTSTRAPPING IMPROVES POSITIVE
OUTPUT SWING. CONNECT PINS 3 AND 10 TO VS IF NOT
USED. TYPICAL CURRENTS ARE 12mA EACH.
Figure 3 shows a bootstrap which dynamically couples the
output waveform onto the VBOOST pin. This causes VBOOST to
swing positive from it's initial value, which is equal to +VS -0.7 V
(one diode drop), an amount equal to the output. In other
words, if VBOOST was initially 19.3, and the output swings
positive 18 Volts, the voltage on the VBOOST pin will swing to 19.3
-0.7 + 18 or 36.6. The capacitor needs to be sized based on a
1K Ω impedance and the lowest frequency required by the
circuit. For example, 20Hz will require > 8uF.
ISENSE
The ISENSE pin is in series with the negative half of the output
stage only. Current will flow through this pin only when negative current is being outputted. The current that flows in this pin
is the same current that flows in the output (if –1A flows in the
output, the ISENSE pin will have 1A of current flow, if +1A flows
in the output the ISENSE pin will have 0 current flow).
The resistor choice is arbitrary and is selected to provide
whatever voltage drop the engineer desires, up to a maximum
of 1.0 volt. However, any voltage dropped across the resistor
will subract from the swing to rail. For instance, assume a +/–
12 volt power supply and a load that requires +/–1A. With no
current sense resistor the output could swing +/–10.2 volts. If
a 1 Ω resistor is used for current sense (which will drop 1 Volt
at 1 Amp) then the output could swing +10.2, –9.2 Volts.
RS
RS
RIN
–VS OR GND
RS
VREF
FIGURE 4. ISENSE TRANSCONDUCTANCE BRIDGING
AMPLIFIER
Figure 4 shows the PA29 ISENSE feature being used to obtain
a Transconductance function. In this example, amplifier "A" is
the master and amplifier "B" is the slave. Feedback from
sensing resistors RS is applied to the summing network and
scaled to the inverting input of amplifier "A" where it is compared to the input voltage. The current sensing feedback
imparts a Transconductance feature to the amplifiers transfer
function. In other words, the voltage developed across the
sensing resistors is directly proportional to the output current.
Using this voltage as a feedback source allows expressing the
gain of the circuit in amperes vs input voltage. The transfer
funcion is approximately:
IL + (VIN – VREF) =
RIN
RFB * RS
In the illustration, resistors RIN, RFB and RS determine gain.
MOUNTING PRECAUTIONS
1. Always use a heat sink. Even unloaded, the PA29 can
dissipate up to 3.6 watts. A thermal washer or thermal
grease should always be used.
2. Avoid bending the leads. Such action can lead to internal
damage.
3. Always fasten the tab to the heat sink before the leads are
soldered to fixed terminals.
4. Strain relief must be provided if there is any probability of
axial stress to the leads.
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.
PA28/29U REV. A MARCH 2000 © 2000 Apex Microtechnology Corp.