TPA12/ TPA12A
Power Operational Amplifier
FEATURES
•HIGH OUTPUT CURRE NT - ±15A PE AK
•HIGH VOLTAGE RATIN G - ± 50V
•LOW THERMAL RESIST ANCE – 1.4 oC/W
•CURRENT FOLDOVER PROTECTION
•EXCELLENT LINEARITY - CLASS A/B OUTPUT
APPLICATIONS
•MOTOR, VALVE AND ACTUATOR C ONTROL
•MAGNETIC DEFLECTION CIRCUITS UP T O 10 A
•POWER TRANSDUCERS UP TO 100 kHz
•AUDIO AMPLIFIERS UP TO 120W RMS
TPA12/12A Rev. B Oct. 2006
DESCRIPTION
The TPA12 and TPA12A are designed for high
voltage and high current applications. They can
deliver up to 600 Watts of power to a load. The
safe operating area (SOA) at the output stage can
be guaranteed for all operating conditions by
properly selecting the external current limiting
resistor.
The class A/B output stage delivers power with
remarkably low distortion (see graph page 3). In
order to maintain stable bias current and low
distortion over the operating temperature range a
resistor/thermistor network in the VBE multiplier is
used to closely match the VBE of the output
transistors.
THALER CORPORATION • 2015 N. FORBES BOULEVARD • TUCSON, AZ. 85745 • (520) 882-4000
EQUIVALENT SCHEMATIC
D1
A1
3
4
5
6
8
7
1
2
EXTERNAL CONNECTIONS AND PIN
CONFIGURATIONS
TOP VIEW
1
2
3
4
5
67
8
CL+
+Vs
F.O.
OUT
+IN
-Vs
CL-
-IN
RCL-
RCL+
OUTPUT
°C/W
°C/W
°C/W
°C
*
*
+125
*
*
*
-55
0.9
1.4
+85
0.8
1.25
30
-25
Tc= -55 to +125°C, F>60Hz
Tc= -55 to +125°C
Tc= -55 to +125°C
Meets full range specifications
THERMAL
Resistance, AC junction to case4
Resistance, DC junction to case
Resistance, junction to air
Temperature Range, case
V
mA
±50
*
*
*
*±45
50
±40
25
±10full temp range
Tc= 25°C
POWER SUPPLY
Voltage
Current, quiescent
V
V
V
A
µs
V/µs
nF*
*
*
*
*
*
*
15
*
1.5
SOA
2
4
±Vs-6
±Vs-5
±Vs-5
10
2.5
T c=25°C,TPA12 =10A, TPA12A=15A
Tc= 25°C, Io= 5A
full temp range, Io= 80mA
Tc= 25°C
T c= 25°C, 2V step
Tc= 25°C
full temp range, Av = 4
full temp range, Av >10
OUTPUT
Voltage Swing3
Voltage Swing3
Voltage Swing3
Current, peak
Settling Time to .1%,
Slew Rate
Capacitive Load
Capacitive Load
db
db
MHz
kHz
o
*
*
*
*
*
*
*
110
108
4
20
20
96
13
Tc= 25°C, 1kΩload
Full temp range, 8Ωload
Tc= 25°C, 8Ωload
T c= 25°C, 8Ωload
Full temp range, 8Ωload
GAIN
Open Loop Gain at 10Hz
Open Loop Gain at 10Hz
Gain Bandwidth Product (1MHz)
Power Bandwidth
Phase Margin AV= +4
mV
µV/°C
µV/V
µV/W
nA
pA/°C
pA/V
nA
pA/°C
MΩ
pF
V
db
±4
±40
*
20
*
±20
±1
*
*
*
10
*
*
±5
*
*
*
*
*
*
*
±6
±65
±200
± 30
± 500
±30
±2
±10
±30
±20
±12
±50
±10
±12
±50
200
3
±V
s-3
100
±Vs-5
74
Tc= 25°C
full temperature range
Tc= 25°C
Tc= 25°C
Tc= 25°C
full temperature range
T c= 25°C
T c= 25°C
full temperature range
Tc= 25°C
Tc= 25°C
full temperature range
full temp. range VCM = ±Vs-5
INPUT
Offset Voltage, initial
Offset Voltage, vs. temp.
Offset Voltage, vs. supply
Offset Voltage, vs. power
Bias Current, initial
Bias Current, vs. temp.
Bias Current, vs. supply
Offset Current, initial
Offset Current, vs. temp.
Input Impedance, DC
Input Capacitance
Common Mode Volt. Range3
Common Mode Rejection, DC
UNITSMAXTYPMINMAXTYPMIN
CONDITIONS 2,5
PARAMETER
ABSOLUTE MAXIMUM RATINGS
Supply Voltage 100V Temperature, pin solder – 10s 300°C
Output Current, within SOA 15A Temperature, junction1200°C
Power Dissipation, internal 125W Temperature range, storage -65 to +150°C
Input Voltage, differential ±VS -3V Operating temperature range, case -55 to +125°C
Input Voltage, common mode ±VS
Electrical Specifications TPA12 TPA12A
TPA12/TPA12A
Notes: *Same as previous Model.
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
±40V 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. Exceeding CMV range can cause the output to latch.
Caution: The internal substrate contains beryllia (BeO). Do not crush, break, machine or subject t h e substra t e t o te mper a t ures
in excess of 850C. TPA12/12A Rev. B Oct. 2006
TYPICAL PERFORMANCE CURVES
POWER DERATING CURRENT LIMIT
BIAS CURRENT
COMMON MODE REJECTION INPUT NOISE
PULSE RESPONSE
SMALL SIGNAL RESPONSE POWER RESPONSEPHASE RESPONSE
HARMONIC DISTORTION OUTPUT VOLTAGE SWING
QUIESCENT CURRENT
INTERNAL POWER DISSIPATION (W)
140
120
100
80
60
40
20
0
0 20 40 60 80 100 120 140
CASE TEMPERATURE oC
-50 -25 0 25 50 75 100 125
CASE TEMPERATURE oC
NORMALIZED BIAS CURRENT (X)
2.5
2.2
1.9
1.6
1.3
1.0
.7
.4
-50 -25 0 25 50 75 100 125
CASE TEMPERATURE oC
OPEN LOOP GAIN (dB)
120
100
80
60
40
20
0
-20
1 10 100 1K 10K 100K 1M 10M
FREQUENCY (Hz)
1 10 100 1K 10K 100K 1M 10M
FREQUENCY (Hz)
PHASE (o)
0
-30
-60
-90
-120
-150
-180
-210
1 10 100 1K 10K 100K 1M
FREQUENCY (Hz)
COMMON MODE REJECTION (dB)
120
100
80
60
40
20
0
OUTPUT VOLTAGE (V)
8
6
4
2
0
-2
-4
-6
-8
0 2 4 6 8 10 12
TIME (µs)
40 50 60 70 80 90 100
TOTAL SUPPLY VOLTAGE (V)
NORMALIZED (X)
1.6
1.4
1.2
1.0
0.8
0.6
0.4
100 300 1K 3K 10K 30K 100K
FREQUENCY (Hz)
DISTORTION (%)
3
1
0.3
0.1
0.03
0.01
0.003
CURRENT LIMIT (A)
17.5
15.0
12.5
10.0
7.5
5.0
2.5
0
10K 20K 30K 50K 70K 100K
FREQUENCY (Hz)
OUTPUT VOLTAGE (VP-P)
100
68
46
32
22
15
10
6.8
4.6
10 100 1K 10K 100K
FREQUENCY (Hz)
INPUT NOISE VOLTAGE (nV/√Hz))
100
70
50
40
30
20
10
VOLTAGE DROP FROM SUPPLY (V)
6
5
4
3
2
1
0 3 6 9 12 15
OUTPUT CURRENT (A)
abs(+Vs)+abs(-Vs)=100V
abs(+Vs)+abs(-Vs)=80V
abs(+Vs)+abs(-Vs)=30V
RCL = 0.06Ω, RFO = ∞
RCL = 0.18Ω, RFO = 0
Vo= 0V
Vo= 24V
Vo= 0V
Vo= -24V
TPA12A
TPA12
VIN = ±5V, tr= 100ns
T
c
= -25oC
T
c
= 125
o
C
T
c
= 85
o
C
P
o
= 4W
Po= 120W
Po= 100mW
AV= 10
VS= ±37V
RL= 4Ω
T
c
= 25oC
+Vo
-Vo
TPA12/12A Rev. B Oct. 2006
DISCUSSION OF PERFORMANCE
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 resistors.
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.Capacitive and dynamic* loads up to the following
maximums are safe with the current limits set as
specified.
2. The amplifier can handle any EMF generating or
reactive load and short circuits to the supply rail or
common if the current limits are set as follows at
Tc= 25OC.
* 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 = 15A or 25V below the
supply rail with ILIM = 5A while the amplifier is current
limiting, the inductor must be capacitively coupled or the
current limit must be lowered to meet SOA criteria.
These simplified limits may be exceeded with further
analysis using the operating conditions for a specific
application.
CURRENT LIMIT
For fixed current limit, leave pin 7 open and use the
equations in 1 and 2.
RCL = 0.65/LCL (1)
ICL = 0.65/RCL (2)
Where:
ICL is the current limit in amperes.
RCL is the current limit resistor in ohms.
For certain applications the foldover current limit
adds a slope to the current limit which allows more
power to be delivered to the load without violating
the SOA. For maximum foldover slope, ground pin
7and use equations 3 and 4.
ICL= (0.65+(Vo*0.014)) / RCL (3)
RCL =( 0.65 + (Vo* 0.014)) / ICL (4)
Where Vo is the output voltage in volts.
Most designers start with either equation 1 to set
RCL for the desired output current at 0V out or with
equation 4 set to RCL at the maximum output
voltage. Equation 3 should then be used to plot the
resulting foldover limits on the SOA graph. If
equation 3 results in a negative current limit,
foldover slope must be reduced. This can happen
when the output voltage is the opposite polarity of
the supply conducting the current.
In applications where a reduced foldover slope is
desired, this can be achieved by adding a resistor
(RFO) between pin 7 and ground. Use equations 5
and 6 with this new resistor in the circuit.
ICL= ((0.65+(VO*0.014)/(10.14+RFO)) / RCL (5)
RCL= ((0.65+(VO*0.014)/(10.14+RFO)) / ICL (6)
Where RFO is in K ohms.
Capacitive Load Inductive Load
±VsILIM = 5A ILIM = 10A ILIM = 5A ILIM= 10A
50V 200µF 125µF5mH2.0mH
40V 500µF 350µF15mH3.0mH
35V 2.0mF 850µF50mH5.0mH
30V 7.0mF 2.5mF 150mH 10mH
25V 25mF 10mF 500mH 20mH
20V 60mF 20mF 1,000mH 30mH
15V 150mF 60mF 2,500mH 50mH
Short to ±VSShort to
±Vs C,L or EMF Load Common
50V 0.30A 2.4A
40V 0.58A 2.9A
35V 0.87A 3.7A
30V 1.50A 4.1A
25V 2.40A 4.9A
20V 2.90A 6.3A
15V 4.20A 8.0A
OUTPUT CURRENT FROM +VsOR -Vs(A)
15
10
6.0
4.0
2.0
1.0
0.6
0.4
0.3
10 20 30 40 50 70 100
SUPPLY TO OUTPUT DIFFERENTIAL VOLTAGE (V)
SOA
SECOND BREAKDOWN
THERMAL
T
C
= 23
o
C
T
C
= 85
o
C
T
C
= 125
o
C
STEADY STATE
t = 0.5ms
t = 1ms
t = 5ms
TPA12/12A Rev. B Oct. 2006
MECHANICAL
TO3-8 Package
TPA12/12A Rev. B Oct. 2006
