Burr-Brown OPA547 High-voltage, high-current operational amplifier Datasheet

OPA547
OPA
547
OPA
547
SBOS056A – JANUARY 2002
High-Voltage, High-Current
OPERATIONAL AMPLIFIER
FEATURES
DESCRIPTION
● WIDE SUPPLY RANGE
Single Supply: +8V to +60V
Dual Supply: ±4V to ±30V
● HIGH OUTPUT CURRENT:
500mA Continuous
● WIDE OUTPUT VOLTAGE SWING
● FULLY PROTECTED:
Thermal Shutdown
Adjustable Current Limit
● OUTPUT DISABLE CONTROL
● THERMAL SHUTDOWN INDICATOR
● HIGH SLEW RATE: 6V/µs
● LOW QUIESCENT CURRENT
● PACKAGES:
7-Lead TO-220
7-Lead DDPAK Surface-Mount
The OPA547 is a low cost, high-voltage/high-current operational amplifier ideal for driving a wide variety of loads. A
laser-trimmed monolithic integrated circuit provides excellent low-level signal accuracy and high output voltage and
current.
The OPA547 operates from either single or dual supplies for
design flexibility. In single supply operation, the input
common-mode range extends below ground.
The OPA547 is internally protected against over-temperature conditions and current overloads. In addition, the
OPA547 was designed to provide an accurate, user-selected
current limit. Unlike other designs which use a “power”
resistor in series with the output current path, the OPA547
senses the load indirectly. This allows the current limit to be
adjusted from 0 to 750mA with a 0 to 150µA control signal.
This is easily done with a resistor/potentiometer or controlled digitally with a voltage-out or current-out DAC.
The Enable/Status (E/S) pin provides two functions. An
input on the pin not only disables the output stage to
effectively disconnect the load but also reduces the quiescent to conserve power. The E/S pin output can be monitored to determine if the OPA547 is in thermal shutdown.
The OPA547 is available in an industry-standard
7-lead staggered TO-220 package and a 7-lead DDPAK
surface-mount plastic power package. The copper tab allows
easy mounting to a heat sink or circuit board for excellent
thermal performance. It is specified for operation over the
extended industrial temperature range, –40°C to +85°C.
APPLICATIONS
●
●
●
●
●
●
VALVE, ACTUATOR DRIVER
SYNCHRO, SERVO DRIVER
POWER SUPPLIES
TEST EQUIPMENT
TRANSDUCER EXCITATION
AUDIO AMPLIFIER
V+
–
VIN
OPA547
VO
ILIM
+
VIN
RCL
(0.25W
Signal Resistor)
RCL sets the current limit
value from 0 to 750mA.
E/S
V–
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Copyright © 1997, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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ABSOLUTE MAXIMUM RATINGS(1)
Output Current ................................................................. See SOA Curve
Supply Voltage, V+ to V– ................................................................... 60V
Input Voltage ....................................................... (V–)–0.5V to (V+)+0.5V
Input Shutdown Voltage ........................................................................ V+
Operating Temperature .................................................. –40°C to +125°C
Storage Temperature ..................................................... –55°C to +125°C
Junction Temperature ...................................................................... 150°C
Lead Temperature (soldering 10s)(2) .............................................. 300°C
NOTE: (1) Stresses above these ratings may cause permanent damage. (2)
Vapor-phase or IR reflow techniques are recommended for soldering the
OPA547F surface mount package. Wave soldering is not recommended due to
excessive thermal shock and “shadowing” of nearby devices.
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
PACKAGE/ORDERING INFORMATION
PRODUCT
PACKAGE-LEAD
PACKAGE
DESIGNATOR(1)
SPECIFIED
TEMPERATURE
RANGE
PACKAGE
MARKING
ORDERING
NUMBER
TRANSPORT
MEDIA, QUANTITY
OPA547T
TO-220-7
KV
–40°C to +85°C
OPA547T
OPA547T
Tubes, 49
OPA547F
"
DDPAK-7
"
KTW
"
–40°C to +85°C
"
OPA547F
OPA547F
OPA547F
OPA547F/500
Tubes, 49
Tape and Reel, 500
NOTES: (1) For the most current specifications and package information, refer to our web site at www.ti.com.
PIN CONFIGURATIONS
Top Front View
7-Lead
Stagger-Formed
TO-220
7-Lead
DDPAK
Surface-Mount
1 2 3 4 5 6 7
1 2 3 4 5 6 7
+
VIN
ILIM V+ E/S
–
VIN
V– VO
+
VIN
ILIM V+ E/S
–
VIN
V– VO
NOTE: Tabs are electrically connected to V– supply.
2
OPA547
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SBOS056A
ELECTRICAL CHARACTERISTICS
At TCASE = +25°C, VS = ±30V and E/S pin open, unless otherwise noted.
OPA547T, F
PARAMETER
OFFSET VOLTAGE
Input Offset Voltage
vs Temperature
vs Power Supply
INPUT BIAS CURRENT(1)
Input Bias Current(2)
vs Temperature
Input Offset Current
CONDITION
MIN
TYP
MAX
UNITS
VCM = 0, IO = 0
TA = –40°C to +85°C
VS = ±4V to ±30V
±1
±25
10
±5
mV
µV/°C
µV/V
VCM = 0V
–100
±0.5
±5
VCM = 0V
NOISE
Input Voltage Noise Density, f = 1kHz
Current Noise Density, f = 1kHz
INPUT VOLTAGE RANGE
Common-Mode Voltage Range: Positive
Negative
Common-Mode Rejection
Linear Operation
Linear Operation
VCM = (V–) –0.1V to (V+) –3V
(V+) –3
(V–) –0.1
80
INPUT IMPEDANCE
Differential
Common-Mode
OPEN-LOOP GAIN
Open-Loop Voltage Gain, f = 10Hz
FREQUENCY RESPONSE
Gain-Bandwidth Product
Slew Rate
Full Power Bandwidth
Settling Time: ±0.1%
Total Harmonic Distortion + Noise, f = 1kHz
OUTPUT
Voltage Output, Positive
Negative
Positive
Negative
Maximum Continuous Current Output: dc
ac
Leakage Current, Output Disabled, dc
Output Current Limit
Current Limit Range
Current Limit Equation
Current Limit Tolerance(1)
VO = ±25V, RL = 1kΩ
VO = ±25V, RL = 50Ω
100
RL = 50Ω
G = 1, 50Vp-p, RL = 50Ω
G = –10, 50V Step
RL = 50Ω, G = +3V, 1W Power
IO = 0.5A
IO = –0.5A
IO = 0.1A
IO = –0.1A
(V+) –2.2
(V–) +1.6
(V+) –1.8
(V–) +1.2
±500
500
POWER SUPPLY
Specified Voltage
Operating Voltage Range
Quiescent Current
Quiescent Current, Shutdown Mode
TEMPERATURE RANGE
Specified Range
Operating Range
Storage Range
Thermal Resistance, θJC
7-Lead DDPAK, 7-Lead TO-220
7-Lead DDPAK, 7-Lead TO-220
Thermal Resistance, θJA
7-Lead DDPAK, 7-Lead TO-220
–500
±50
nA
nA/°C
nA
90
200
nV/√Hz
fA/√Hz
(V+) –2.3
(V–) –0.2
95
V
V
dB
107 || 6
109 || 4
Ω || pF
Ω || pF
115
110
dB
dB
1
6
See Typical Curve
18
0.004(3)
MHz
V/µs
kHz
µs
%
(V+) –1.9
(V–) +1.3
(V+) –1.5
(V–) +0.8
V
V
V
V
mA
mArms
See Typical Curve
0 to ±750
ILIM = (5000)(4.75)/(31600Ω + RCL)
±10
±30
RCL = 31.6kΩ (ILIM = ±375mA),
RL = 50Ω
mA
A
mA
See Typical Curve(4)
Capacitive Load Drive
OUTPUT ENABLE /STATUS (E/S) PIN
Shutdown Input Mode
VE/S High (output enabled)
VE/S Low (output disabled)
IE/S High (output enabled)
IE/S Low (output disabled)
Output Disable Time
Output Enable Time
Thermal Shutdown Status Output
Normal Operation
Thermally Shutdown
Junction Temperature, Shutdown
Reset from Shutdown
100
E/S Pin Open or Forced High
E/S Pin Forced Low
E/S Pin High
E/S Pin Low
(V–) +2.4
Sourcing 20µA
Sinking 5µA, TJ > 160°C
(V–) +2.4
(V–) +0.8
–60
–65
1
3
±4
ILIM Connected to V–, IO = 0
ILIM Connected to V–
(V–) +3.5
(V–) +0.35
+160
+140
±30
±10
±4
–40
–40
–55
(V–) +0.8
V
V
µA
µA
µs
ms
V
V
°C
°C
±30
±15
V
V
mA
mA
+85
+125
+125
°C
°C
°C
f > 50Hz
dc
2
3
°C/W
°C/W
No Heat Sink
65
°C/W
NOTES: (1) High-speed test at TJ = +25°C. (2) Positive conventional current flows into the input terminals. (3) See “Total Harmonic Distortion+Noise” in the Typical
Characteristics section for additional power levels. (4) See “Small-Signal Overshoot vs Load Capacitance” in the Typical Characteristics section.
OPA547
SBOS056A
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3
TYPICAL CHARACTERISTICS
At TCASE = +25°C, VS = ±30V and E/S pin open, unless otherwise noted.
OPEN-LOOP GAIN AND PHASE
vs FREQUENCY
INPUT BIAS CURRENT vs TEMPERATURE
–160
120
RL = 50Ω
φ
60
–45
40
–90
20
–135
0
–180
Phase (°)
Gain (dB)
0
Input Bias Current (nA)
G
80
–120
10
100
1k
10k
100k
1M
VS = ±30V
–100
IB
–80
–60
–40
–20
0
–75
–20
1
VS = ±5V
–140
100
10M
–50
–25
0
25
50
75
100
125
150
Temperature (°C)
Frequency (Hz)
CURRENT LIMIT vs TEMPERATURE
CURRENT LIMIT vs SUPPLY VOLTAGE
±600
±600
+ILIM
±550
RCL = 15.9kΩ
Current Limit (mA)
Current Limit (mA)
±500
RCL = 31.6kΩ
±400
±300
RCL = 63.4kΩ
±500
±450
+400
RCL = 31.6kΩ
±350
±300
±200
RCL = 63.4kΩ
±250
±100
–75
–ILIM
RCL = 15.9kΩ
±200
–50
–25
0
25
50
75
100
125
150
0
±5
±10
Temperature (°C)
±15
±20
±25
±30
Supply Voltage (V)
QUIESCENT CURRENT vs TEMPERATURE
VOLTAGE NOISE DENSITY vs FREQUENCY
±12
400
VS = ±30V
Quiescent Current (mA)
Voltage Noise (nV/√Hz)
IQ
300
200
100
±10
±8
VS = ±5V
±6
VS = ±30V
IQ Shutdown
±4
VS = ±5V
±2
–75
0
1
10
100
1k
10k
100k
1M
4
–50
–25
0
25
50
75
100
125
150
Temperature (°C)
Frequency (Hz)
OPA547
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SBOS056A
TYPICAL CHARACTERISTICS (Cont.)
At TCASE = +25°C, VS = ±30V and E/S pin open, unless otherwise noted.
POWER SUPPLY REJECTION
vs FREQUENCY
COMMON-MODE REJECTION vs FREQUENCY
120
90
Power Supply Rejection (dB)
80
70
60
50
40
30
100
+PSRR
80
60
40
–PSRR
20
20
0
10
100
1k
10k
100k
1
1M
10
100
100k
1M
120
105
AOL
40
115
100
G = +1
3
G = –1
20
CMRR
CMRR (dB)
Overshoot (%)
10k
OPEN-LOOP GAIN, COMMON-MODE REJECTION,
AND POWER SUPPLY REJECTION vs TEMPERATURE
SMALL-SIGNAL OVERSHOOT
vs LOAD CAPACITANCE
50
1k
Frequency (Hz)
Frequency (Hz)
100
95
PSRR
PSRR, AOL (dB)
Common-Mode Rejection (dB)
100
95
90
10
85
–75
0
0
2k
4k
6k
8k
10k
12k
14k
16k
18k
20k
–50
–25
0
GAIN-BANDWIDTH PRODUCT AND
SLEW RATE vs TEMPERATURE
6
SR–
1W
0.01
THD+N (%)
6.5
0.5
0.1W
6.25W
0.001
5.5
0
25
50
75
100
125
5
150
0.0001
Temperature (°C)
20
100
1k
10k
20k
Frequency (Hz)
OPA547
SBOS056A
90
150
7
0.75
–25
125
RL = 50Ω
G = +3
GBW
–50
100
0.1
Slew Rate (V/µs)
Gain-Bandwidth Product (MHz)
7.5
SR+
0
–75
75
TOTAL HARMONIC DISTORTION+NOISE
vs FREQUENCY
1.25
0.25
50
Temperature (°C)
Load Capacitance (pF)
1
25
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5
TYPICAL CHARACTERISTICS (Cont.)
At TCASE = +25°C, VS = ±30V and E/S pin open, unless otherwise noted.
OUTPUT VOLTAGE SWING vs TEMPERATURE
OUTPUT VOLTAGE SWING vs OUTPUT CURRENT
2.5
3
IO = +500mA
IO = +100mA
2
VSUPPLY – VOUT (V)
VSUPPLY– VOUT (V)
2.5
(V+) –VO
1.5
1
(V–) –VO
0.5
1.5
1
IO = –500mA
0.5
IO = –100mA
0
0
100
200
300
400
500
0
–75
600
–50
–25
0
25
50
MAXIMUM OUTPUT VOLTAGE SWING
vs FREQUENCY
OUTPUT LEAKAGE CURRENT
vs APPLIED OUTPUT VOLTAGE
150
10
Leakage Current (mA)
15
RL = 10Ω
VS = ±30V
0.5
RCL = 31.6kΩ
RCL = ∞
0
RCL = 0
–0.5
Output Disabled
VE/S < (V–) + 0.8V
5
0
1k
10k
100k
–1
–40
1M
–30
–20
–10
0
10
Frequency (Hz)
Output Voltage (V)
OFFSET VOLTAGE
PRODUCTION DISTRIBUTION
OFFSET VOLTAGE DRIFT
PRODUCTION DISTRIBUTION
25
20
Typical production
distribution of
packaged units.
Percent of Amplifiers (%)
Percent of Amplifiers (%)
125
1
Maximum Output
Voltage Without
Slew Rate Induced
Distortion
20
16
100
Output Current (mA)
25
18
75
Temperature (°C)
30
Output Voltage (Vp)
2
14
12
10
8
6
4
20
30
Typical production
distribution of
packaged units.
20
15
10
5
2
0
0
0
–5
–4
–3
–2
–1
0
1
2
3
4
5
5
10 15 20 25 30 35 40 45 50 55 60 65 70
Offset Voltage Drift (µV/°C)
Offset Voltage (mV)
6
OPA547
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SBOS056A
TYPICAL CHARACTERISTICS (Cont.)
At TCASE = +25°C, VS = ±35V and E/S pin open, unless otherwise noted.
SMALL SIGNAL STEP RESPONSE
G = 3, CL = 1000pF
50mV/div
50mV/div
SMALL SIGNAL STEP RESPONSE
G = 1, CL = 1000pF
2µs/div
2µs/div
10V/div
LARGE SIGNAL STEP RESPONSE
G = 3, CL = 100pF, RL = 50Ω
5µs/div
OPA547
SBOS056A
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7
APPLICATIONS INFORMATION
Figure 1 shows the OPA547 connected as a basic noninverting amplifier. The OPA547 can be used in virtually
any op amp configuration.
Power supply terminals should be bypassed with low series
impedance capacitors. The technique shown, using a ceramic and tantalum type in parallel is recommended. Power
supply wiring should have low series impedance.
G = 1+
0.1µF(2)
R1
2
R2
R1
The low level control signal (0 to 150µA) also allows the
current limit to be digitally controlled with a current-out or
voltage-out DAC reference to V– according to the equations
given in Figure 3.
SAFE OPERATING AREA
Stress on the output transistors is determined both by the
output current and by the output voltage across the conducting output transistor, VS – VO. The power dissipated by the
output transistor is equal to the product of the output current
and the voltage across the conducting transistor, VS – VO.
The Safe Operating Area (SOA curve, Figure 2) shows the
permissible range of voltage and current.
E/S
7
OPA547
6
3
1
ILIM(1)
VO
ZL
0.1µF(2)
10µF
+
V–
SAFE OPERATING AREA
NOTE: (1) ILIM connected to V– gives the maximum current
limit, 750mA (peak). (2) Connect 0.1µF capacitors directly
to package power supply pins.
FIGURE 1. Basic Circuit Connections.
POWER SUPPLIES
The OPA547 operates from single (+8V to +60V) or dual
(±4V to ±30V) supplies with excellent performance. Most
behavior remains unchanged throughout the full operating
voltage range. Parameters which vary significantly with
operating voltage are shown in the typical characteristics
curves.
Some applications do not require equal positive and negative
output voltage swing. Power supply voltages do not need to
be equal. The OPA547 can operate with as little as 8V
between the supplies and with up to 60V between the
supplies. For example, the positive supply could be set to
55V with the negative supply at –5V, or vice-versa.
ADJUSTABLE CURRENT LIMIT
The OPA547 features an accurate, user-selected current
limit. Current limit is set from 0 to 750mA by controlling the
input to the ILIM pin. Unlike other designs which use a power
resistor in series with the output current path, the OPA547
senses the load indirectly. This allows the current limit to be
set with a 0 to 150µA control signal. In contrast, other
designs require a limiting resistor to handle the full output
current (750mA in this case).
Output Current (mA)
1k
8
(5000)(4. 75)
– 31.6kΩ
I LIM
R2
5
VIN
R CL =
Figure 3 shows a simplified schematic of the internal circuitry used to set the current limit. Leaving the ILIM pin open
programs the output current to zero, while connecting ILIM
directly to V– programs the maximum output current limit,
typically 750mA.
V+
10µF
+
With the OPA547, the simplest method for adjusting the
current limit uses a resistor or potentiometer connected
between the ILIM pin and V– according to the equation:
Current-Limited
TC = 25°C
Output current may
be limited to less
than 500mA—see text.
100
TC = 85°C
TC = 125°C
Pulse Operation Only (<50% Duty-Cycle)
10
1
2
5
10
20
50
100
VS – VO (V)
FIGURE 2. Safe Operating Area.
The safe output current decreases as VS – VO increases. Output short-circuits are a very demanding case for SOA. A
short-circuit to ground forces the full power supply voltage
(V+ or V–) across the conducting transistor. With TC = 25°C
the maximum output current of 500mA can be achieved
under most conditions. Increasing the case temperature reduces the safe output current that can be tolerated without
activating the thermal shutdown circuit of the OPA547. For
further insight on SOA, consult Application Bulletin
AB-039.
POWER DISSIPATION
Power dissipation depends on power supply, signal and load
conditions. For dc signals, power dissipation is equal to the
product of output current times the voltage across the con-
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ducting output transistor. Power dissipation can be minimized by using the lowest possible power supply voltage
necessary to assure the required output voltage swing.
heat sink required depends on the power dissipated and on
ambient conditions. Consult Application Bulletin AB-038 for
information on determining heat sink requirements. The internal protection circuitry was designed to protect against
overload conditions. It does not activate until the junction
temperature reaches approximately 160°C and was not intended to replace proper heat sinking. Continuously running
the OPA547 into thermal shutdown will degrade reliability.
For resistive loads, the maximum power dissipation occurs
at a dc output voltage of one-half the power supply voltage.
Dissipation with ac signals is lower. Application Bulletin
AB-039 explains how to calculate or measure power dissipation with unusual signals and loads.
The tab of the DDPAK surface-mount version should be
soldered to a circuit board copper area for good heat dissipation. Figure 4 shows typical thermal resistance from
junction to ambient as a function of the copper area.
HEAT SINKING
Most applications require a heat sink to assure that the
maximum junction temperature (150°C) is not exceeded. The
RESISTOR METHOD
DAC METHOD (Current or Voltage)
VO
G = 5000
G = 5000
31.6kΩ
4.75V
4.75V
7
7
RCL
6
D/A
0.01µF
(optional, for noisy
environments)
6
V–
V–
RCL =
VO
31.6kΩ
5000 (4.75V)
ILIM
IDAC = ILIM/5000
– 31.6kΩ
VDAC = (V–) + 4.75V – (31.6kΩ) (ILIM)/5000
OPA547 CURRENT LIMIT: 0 to 750mA
DESIRED
CURRENT LIMIT
RESISTOR(1)
(RCL)
CURRENT DAC
(IDAC)
VOLTAGE DAC
(VDAC)
0mA
100mA
375mA
500mA
750mA
ILIM Open
205kΩ
31.6kΩ
15.8kΩ
ILIM Shorted to V–
0µA
20µA
75µA
100µA
150µA
(V–) + 4.75V
(V–) + 4.12V
(V–) + 2.38V
(V–) + 1.59V
(V–) + 0.01V
NOTE: (1) Resistors are nearest standard 1% values.
FIGURE 3. Adjustable Current Limit.
THERMAL RESISTANCE vs
CIRCUIT BOARD COPPER AREA
Circuit Board Copper Area
Thermal Resistance, θJA (°C/W)
50
OPA547F
Surface Mount Package
1oz copper
40
30
20
10
0
0
1
2
3
4
OPA547
Surface Mount Package
5
Copper Area (inches2)
FIGURE 4. Thermal Resistance vs. Circuit Board Copper Area.
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SBOS056A
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9
THERMAL PROTECTION
The OPA547 has thermal shutdown that protects the amplifier from damage. Activation of the thermal shutdown circuit during normal operation is an indication of excessive
power dissipation or an inadequate heat sink. Depending on
load and signal conditions, the thermal protection circuit
may cycle on and off. This limits the dissipation of the
amplifier but may have an undesirable effect on the load.
The thermal protection activates at a junction temperature of
approximately 160°C. However, for reliable operation junction temperature should be limited to 150°C. To estimate the
margin of safety in a complete design (including heat sink),
increase the ambient temperature until the thermal protection
is activated. Use worst-case load and signal conditions. For
good reliability, the thermal protection should trigger more
than 35°C above the maximum expected ambient condition
of your application. This produces a junction temperature of
125°C at the maximum expected ambient condition.
ENABLE/STATUS (E/S) PIN
The Enable/Status Pin provides two functions: forcing this
pin low disables the output stage, or, E/S can be monitored
to determine if the OPA547 is in thermal shutdown. One or
both of these functions can be utilized on the same device
using single or dual supplies. For normal operation (output
enabled), the E/S pin can be left open or pulled high (at least
+2.4V above the negative rail).
Output Disable
A unique feature of the OPA547 is its output disable capability. This function not only conserves power during idle
periods (quiescent current drops to approximately 4mA) but
also allows multiplexing in low frequency (f<10kHz), multichannel applications. Signals that are greater than 10kHz
may cause leakage current to increase in devices that are
shutdown. Figure 15 shows the two OPA547s in a switched
amplifier configuration. The on/off state of the two amplifiers is controlled by the voltage on the E/S pin.
To disable the output, the E/S pin is pulled low, no greater
than 0.8V above the negative rail. Typically the output is
shutdown in 1µs. Figure 5 provides an example of how to
implement this function using a single supply. Figure 6 gives
a circuit for dual supply applications. To return the output to
an enabled state, the E/S pin should be disconnected (open) or
pulled to at least (V–) + 2.4V. It should be noted that pulling
the E/S pin high (output enabled) does not disable internal
thermal shutdown.
V+
5V
OPA547
E/S
1
6
5
(1)
HCT or TTL In
1
4
4N38
Optocoupler
V–
NOTE: (1) Optional—may be required to limit leakage
current of optocoupler at high temperatures.
FIGURE 6. Output Disable with Dual Supplies.
Thermal Shutdown Status
Internal thermal shutdown circuitry shuts down the output
when the die temperature reaches approximately 160°C, resetting when the die has cooled to 140°C. The E/S pin can be
monitored to determine if shutdown has occurred. During
normal operation the voltage on the E/S pin is typically 3.5V
above the negative rail. Once shutdown has occurred this
voltage drops to approximately 350mV above the negative rail.
Figure 7 gives an example of monitoring shutdown in a
single supply application. Figure 8 provides a circuit for dual
supplies. External logic circuitry or an LED could be used to
indicate if the output has been thermally shutdown, see
Figure 13.
V+
5V
OPA547
2.49kΩ
E/S
TTL
V–
Zetex
ZVN3310
OR
HCT
FIGURE 7. Thermal Shutdown Status with a Single Supply.
5V
V+
V+
1kΩ
OPA547
2N3906
E/S
22kΩ
470Ω
OPA547
E/S
Zetex
ZVN3310
V–
CMOS or TTL
FIGURE 5. Output Disable with a Single Supply.
10
V–
FIGURE 8. Thermal Shutdown Status with Dual Supplies.
OPA547
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SBOS056A
Output Disable and Thermal Shutdown Status
As mentioned earlier, the OPA547’s output can be disabled
and the disable status can be monitored simultaneously.
Figures 9 and 10 provide examples using a single supply and
dual supplies, respectively.
OUTPUT STAGE COMPENSATION
The complex load impedances common in power op amp
applications can cause output stage instability. For normal
operation output compensation circuitry is not typically
required. However, if the OPA547 is intended to be driven
into current limit, a R/C network may be required. Figure 11
shows an output series R/C compensation (snubber) network
(3Ω in series with 0.01µF) which generally provides excellent stability. Some variations in circuit values may be
required with certain loads.
OUTPUT PROTECTION
Reactive and EMF-generating loads can return load current to the amplifier, causing the output voltage to exceed
the power supply voltage. This damaging condition can
be avoided with clamp diodes from the output terminal to
the power supplies as shown in Figure 11. Schottkey
rectifier diodes with a 1A or greater continuous rating are
recommended.
V+
R1
5kΩ
R2
20kΩ
G=–
R2
= –4
R1
VIN
D1
OPA547
V+
3Ω
(Carbon) Motor
D2
0.01µF
V–
OPA547
E/S
D1, D2 : International Rectifier 11DQ06.
V–
Open Drain
(Output Disable)
HCT
(Thermal Status
Shutdown)
FIGURE 11. Motor Drive Circuit.
FIGURE 9. Output Disable and Thermal Shutdown Status
with a Single Supply.
V+
5V
1
6
5V
OPA547
E/S
5
7.5kΩ
1W
1
6
2
(1)
Zetex
ZVN3310
5
TTL Out
4
4N38
Optocoupler
HCT or TTL In
2
4
4N38
Optocoupler
V–
NOTE: (1) Optional—may be required to limit leakage
current of optocoupler at high temperatures.
FIGURE 10. Output Disable and Thermal Shutdown Status with Dual Supplies.
OPA547
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11
PROGRAMMABLE POWER SUPPLY
A programmable power supply can easily be built using the
OPA547. Both the output voltage and output current are
user-controlled. Figure 13 shows a circuit using potentiometers to adjust the output voltage and current while Figure 14
uses digital-to-analog converters. An LED tied to the E/S pin
through a logic gate indicates if the OPA547 is in thermal
shutdown.
VOLTAGE SOURCE APPLICATION
Figure 12 illustrates how to use the OPA547 to provide an
accurate voltage source with only three external resistors.
First, the current limit resistor, RCL, is chosen according to
the desired output current. The resulting voltage at the ILIM
pin is constant and stable over temperature. This voltage,
VCL, is connected to the noninverting input of the op amp
and used as a voltage reference, thus eliminating the need for
an external reference. The feedback resistors are selected to
gain VCL to the desired output voltage level.
R1
R2
V+
VO = VCL (1 + R2/R1)
4.75V
31.6kΩ
IO =
VCL
ILIM
For Example:
V–
RCL
0.01µF
(Optional, for noisy
environments)
If ILIM = 375mA, RCL = 31.6kΩ
VCL =
31.6kΩ • 4.75V
(31.6kΩ + 31.6kΩ)
Desired VO = 19V, G =
5000 (4.75V)
31.6kΩ + RCL
= 2.375V
19
2.375
Uses voltage developed at ILIM pin
as a moderately accurate reference
voltage.
=8
R1 = 1kΩ and R2 = 7kΩ
FIGURE 12. Voltage Source.
1kΩ
9kΩ
G=1+
+5V
9kΩ
= 10
1kΩ
+30V
14.7kΩ
5
2
V+
6
Output
Adjust
0.8V to 2.5V
VO = 0.8V to 25V(1)
OPA547
1
4
3
7 E/S
74HCT04
ILIM
R ≥ 250Ω
4.7kΩ
V–
+5V
0V to 4.75V
Thermal
Shutdown Status
(LED)
1kΩ
Current
Limit
Adjust
20kΩ
0.01µF(2)
NOTES: (1) For VO = 0V, V– = –1V.
(2) Optional: Improves noise
immunity.
FIGURE 13. Resistor-Controlled Programmable Power Supply.
12
OPA547
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SBOS056A
1kΩ
9kΩ
+10V
OUTPUT ADJUST
VREF
+30V
G = 10
+5V
VREF A
+5V
RFB A
1/2
OPA2336
IOUT A
1/2 DAC7800/1/2(3)
VO = 0.8 to 25V(1)
OPA547
10pF
74HCT04
E/S
DAC A
AGND A
ILIM
IO = 0 to 750mA
R ≥ 250Ω
V–
Thermal
Shutdown Status
(LED)
VREF B
RFB B
10pF
1/2
OPA2336
IOUT B
1/2 DAC7800/1/2(3)
DAC B
0.01µF(2)
DGND
AGND B
CURRENT LIMIT ADJUST
NOTES: (1) For VO = 0V, V– = –1V. (2) Optional, improves noise immunity. (3) Chose DAC780X based on
digital interface: DAC7800 - 12-bit interface, DAC7801 - 8-bit interface + 4 bits, DAC7802 - serial interface.
(4) Can use OPA2237, IO = 100mA to 750mA.
FIGURE 14. Digitally-Controlled Programmable Power Supply.
R1
R2
VIN1
OPA547
ILIM
AMP1
E/S
RC2
RC1
R3
VE/S
R4
Close for high current
(Could be open drain
output of a logic gate).
VO
VIN2
AMP2
V–
E/S
FIGURE 16. Multiple Current Limit Values.
VE/S > (V–) +2.4V: Amp 1 is on, Amp 2 if off
VO = –VIN1
R2
( )
R1
VE/S < (V–) +2.4V: Amp 2 is on, Amp 1 if off
VO = –VIN2
R4
( )
R3
FIGURE 15. Swap Amplifier.
OPA547
SBOS056A
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13
PACKAGE DRAWINGS
MSOT011 – OCTOBER 1994
KV (R-PZFM-T7)
PLASTIC FLANGE-MOUNT PACKAGE
0.181 (4,60)
0.179 (4,55)
0.156 (3,96)
DIA
0.146 (3,71)
0.409 (10,39)
0.399 (10,13)
0.113 (2,87)
0.103 (2,62)
0.055 (1,40)
0.045 (1,14)
0.147 (3,73)
0.137 (3,48)
0.692 (17,58)
0.682 (17,32)
0.335 (8,51)
0.325 (8,25)
0.822 (20,88)
0.812 (20,62)
1
7
0.120 (3,05)
0.110 (2,79)
(see Note C)
0.030 (0,76)
0.026 (0,66)
0.010 (0,25) M
0.122 (3,10)
0.102 (2,59)
0.050 (1,27)
0.025 (0,64)
0.012 (0,30)
0.300 (7,62)
0.317 (8,06)
0.297 (7,54)
4040233 / B 01/95
NOTES: A.
B.
C.
D.
14
All linear dimensions are in inches (millimeters).
This drawing is subject to change without notice.
Lead dimensions are not controlled within this area.
All lead dimensions apply before solder dip.
OPA547
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SBOS056A
PACKAGE DRAWINGS (Cont.)
MPSF015 – AUGUST 2001
KTW (R-PSFM-G7)
PLASTIC FLANGE-MOUNT
0.410 (10,41)
0.385 (9,78)
0.304 (7,72)
–A–
0.006
–B–
0.303 (7,70)
0.297 (7,54)
0.0625 (1,587) H
0.055 (1,40)
0.0585 (1,485)
0.045 (1,14)
0.300 (7,62)
0.064 (1,63)
0.252 (6,40)
0.056 (1,42)
0.187 (4,75)
0.370 (9,40)
0.179 (4,55)
0.330 (8,38)
H
0.296 (7,52)
A
0.605 (15,37)
0.595 (15,11)
0.012 (0,305)
C
0.000 (0,00)
0.019 (0,48)
0.104 (2,64)
0.096 (2,44)
H
0.017 (0,43)
0.050 (1,27)
C
C
F
0.034 (0,86)
0.022 (0,57)
0.010 (0,25) M
B
0.026 (0,66)
0.014 (0,36)
0°~3°
AM C M
0.183 (4,65)
0.170 (4,32)
4201284/A 08/01
NOTES: A. All linear dimensions are in inches (millimeters).
B. This drawing is subject to change without notice.
C. Lead width and height dimensions apply to the
plated lead.
D. Leads are not allowed above the Datum B.
E. Stand–off height is measured from lead tip
with reference to Datum B.
F. Lead width dimension does not include dambar
protrusion. Allowable dambar protrusion shall not
cause the lead width to exceed the maximum
dimension by more than 0.003”.
G. Cross–hatch indicates exposed metal surface.
H. Falls within JEDEC MO–169 with the exception
of the dimensions indicated.
OPA547
SBOS056A
www.ti.com
15
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