OPA633
®
High Speed
BUFFER AMPLIFIER
FEATURES
APPLICATIONS
●
●
●
●
●
●
●
●
WIDE BANDWIDTH: 260MHz
HIGH SLEW RATE: 2500V/µs
HIGH OUTPUT CURRENT: 100mA
LOW OFFSET VOLTAGE: 1.5mV
OP AMP CURRENT BOOSTER
VIDEO BUFFER
LINE DRIVER
A/D CONVERTER INPUT BUFFER
● REPLACES HA-5033
● IMPROVED PERFORMANCE/PRICE:
LH0033, LTC1010, H0S200
DESCRIPTION
+VS
The OPA633 is a monolithic unity-gain buffer amplifier featuring very wide bandwidth and high slew rate.
A dielectric isolation process incorporating both NPN
and PNP high frequency transistors achieves performance unattainable with conventional integrated circuit technology. Laser trimming provides low input
offset voltage.
High output current capability allows the OPA633 to
drive 50Ω and 75Ω lines, making it ideal for RF, IF
and video applications. Low phase shift allows the
OPA633 to be used inside amplifier feedback loops.
OPA633 is available in a low cost plastic DIP package
specified for 0°C to +75°C operation.
1
VIN
VOUT
4
8
–VS
5
SBOS150
International Airport Industrial Park • Mailing Address: PO Box 11400
Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP •
• Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706
Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132
©
PDS-699B
1987 Burr-Brown Corporation
Printed in U.S.A. October, 1993
SPECIFICATIONS
ELECTRICAL
At +25°C, VS = ±12V, RS = 50Ω, RL = 100Ω, and CL = 10pF, unless otherwise specified.
OPA633KP
PARAMETER
CONDITIONS
FREQUENCY RESPONSE
Small Signal Bandwidth
Full Power Bandwidth
Slew Rate
Rise Time, 10% to 90%
Propagation Delay
Overshoot
Settling Time, 0.1%
Differential Phase Error (1)
Differential Gain Error (1)
Total Harmonic Distortion
MIN
VO = 1Vrms, RL = 1kΩ
VO = 10V, VS = ±15V, RL = 1kΩ
VO = 500mV
TA = TMIN to TMAX
RL = 1kΩ, VS = ±15V
Current
Resistance
TRANSFER CHARACTERISTICS
Gain
RL = 1kΩ
TA = TMIN to TMAX
INPUT
Offset Voltage
±8
±11
±80
±10
±13
±100
5
V
V
mA
Ω
0.93
0.95
0.99
0.95
V/V
V/V
V/V
1000
0.92
TA = TMIN to TMAX
TA = +25°C
TA = TMIN to TMAX
10Hz to 1MHz
Noise Voltage
Resistance
Capacitance
POWER SUPPLY
Rated Supply Voltage
Operating Supply Voltage
Current, Quiescent
54
Specified Performance
Derated Performance
IO = 0
IO = 0, TA = TMIN to TMAX
±5
±5
±6
±33
72
±15
±20
20
1.5
1.6
±12
21
21
TEMPERATURE RANGE
Specification, Ambient
Operating, Ambient
θ Junction, Ambient
UNITS
MHz
MHz
V/µs
ns
ns
%
ns
Degrees
%
%
%
TA = +25°C
TA = TMIN to TMAX
vs Temperature
vs Supply
Bias Current
MAX
260
40
2500
2.5
1
10
50
0.1
0.1
0.005
0.02
VO = 1Vrms, RL = 1kΩ, f = 100kHz
VO = 1Vrms, RL = 100Ω, f = 100kHz
OUTPUT CHARACTERISTICS
Voltage
TYP
0
–25
±15
±25
mV
mV
µV/°C
dB
µA
µA
µVp-p
MΩ
pF
±35
±50
V
V
mA
mA
±16
25
30
°C
°C
°C/W
+75
+85
90
NOTE: (1) Differential phase error in video transmission systems is the change in phase of a color subcarrier resulting from a change in picture signal from blanked to
white. Differential gain error is the change in amplitude at the color subcarrier frequency resulting from a change in picture signal from blanked to white.
PIN CONFIGURATION
ABSOLUTE MAXIMUM RATINGS
Power Supply, ±VS ............................................................................ ±20V
Input Voltage VIN ...................................................... +VS + 2V to –VS – 2V
Output Current (peak) ................................................................... ±200mA
Internal Power Dissipation (25°C) .................................................... 1.95W
Junction Temperature ...................................................................... 200°C
Storage Temperature Range ............................................ –40°C to +85°C
Lead Temperature (soldering, 10s) .................................................. 300°C
Top View
+VS
1
8
Out
NC
2
7
NC
NC
3
6
Substrate (ground)
In
4
5
–VS
PACKAGE INFORMATION(1)
MODEL
OPA633KP
OPA633KP
PACKAGE
TEMPERATURE
RANGE
8-Pin Plastic DIP
0°C to +75°C
®
OPA633
PACKAGE DRAWING
NUMBER
8-Pin Plastic DIP
006
NOTE: (1) For detailed drawing and dimension table, please see end of data
sheet, or Appendix D of Burr-Brown IC Data Book.
ORDERING INFORMATION
MODEL
PACKAGE
2
TYPICAL PERFORMANCE CURVES
At +25°C, VS = ±12V, RS = 50Ω, RL = 100Ω, and CL = 10pF, unless otherwise specified.
SMALL SIGNAL BANDWIDTH vs TEMPERATURE
GAIN/PHASE vs FREQUENCY
300
6
4
290
VS = ±15V
Gain (dB)
θ
–2
–20
θ
–4
–40
–60
–6
–8
RS = 300Ω
–10
RS = 50Ω
Phase (degrees)
0
0
Bandwidth (MHz)
2
–80
270
VS = ±5V
260
VO = 0.25Vrms
RL = 100Ω
250
–100
240
–120
–12
10
280
100
–50
1000
–25
0
RS = 1kΩ
5
2.0
4
Sine Wave
Square Wave
RL = 100Ω
3
2.5
3
2
2
(See Text)
1
Power Dissipation (W)
Output Voltage (Vp-p)
RL = 100Ω
6
Output Voltage (Vrms)
6
4
50
75
100
125
100
125
MAXIMUM POWER DISSIPATION
vs AMBIENT TEMPERATURE
SAFE INPUT VOLTAGE vs FREQUENCY
5
25
Temperature (°C)
Frequency (MHz)
1.5
1.0
0.5
1
0
0
0
1
10
–50
100
–25
0
25
50
75
Ambient Temperature (°C)
Frequency (MHz)
SLEW RATE vs LOAD CAPACITANCE
SLEW RATE vs LOAD CAPACITANCE
3500
3000
Rising Edge
2500
2500
Falling Edge
Slew Rate (V/µs)
Slew Rate (V/µs)
3000
2000
VO = ±10V
RL = 1kΩ
1500
1000
2000
1500
VO = ±10V
RL = 100Ω
1000
500
500
0
0
1
10
100
1000
1
Load Capacitance (pF)
10
100
1000
10,000
Load Capacitance (pF)
®
3
OPA633
TYPICAL PERFORMANCE CURVES (CONT)
At +25°C, VS = ±12V, RS = 50Ω, RL = 100Ω, and CL = 10pF, unless otherwise specified.
POWER SUPPLY REJECTION vs FREQUENCY
SLEW RATE vs TEMPERATURE
80
2500
Falling Edge
RL = 1kΩ
70
60
Rising Edge
PSRR (dB)
Slew Rate (V/µs)
2000
1500
Falling Edge
1000
RL = 100Ω
Rising Edge
50
40
30
20
500
10
0
0
–50
–25
0
25
50
75
100
1k
125
10k
Temperature (°C)
1M
INPUT BIAS CURRENT vs TEMPERATURE
QUIESCENT CURRENT vs TEMPERATURE
25
30
VS = ±15V
25
20
VS = ±12V
VS = ±5V
20
IB (µA)
Quiescent Current (mA)
100k
Frequency (Hz)
15
VS = ±5V
15
10
10
5
VS = ±15V
0
5
–50
–25
0
25
50
75
100
–50
125
–25
0
OUTPUT VOLTAGE SWING vs LOAD RESISTANCE
30
25
50
75
100
125
Temperature (°C)
Temperature (°C)
VIN – VOUT vs OUTPUT CURRENT
1.0
VS = ±15V
VS = ±12V
20
VS = ±10V
0.8
VIN – VOUT (V)
VOUT (Vp-p)
0.9
25
15
10
VS = ±5V
0.5
0.4
0
0.1
0
300 400 500
600 700 800
900 1k
Current Sinking
VO = 0
Current Sourcing
0
Load Resistance (Ω)
10
20
30
40
50
60
Output Current (mA)
®
OPA633
VO = 0
0.3
0.2
100 200
VO = +10
0.6
5
0
VO = –10
0.7
4
70
80
90 100
TYPICAL PERFORMANCE CURVES (CONT)
At +25°C, VS = ±12V, RS = 50Ω, RL = 100Ω, and CL = 10pF, unless otherwise specified.
VOLTAGE GAIN vs LOAD RESISTANCE
GAIN ERROR vs TEMPERATURE
100
1.00
VO = 10Vp-p
VO – VIN (mV)
Voltage Gain (V/V)
80
VO = 1Vp-p
0.95
0.90
f = 1kHz
VO = ±10V
RL = 1kΩ
60
40
0.85
20
0
0.80
10
100
1k
–50
10k
–25
0
OUTPUT ERROR vs INPUT VOLTAGE
100
0
–20
RL = 10kΩ
VOS (mV)
20
RL = 1kΩ
0
2
0
–0.4
–40
–0.6
–60
–2
–0.8
–1.0
–80
–100
–4
–10
–8
–6
–4
–2
0
125
4
VIN – VOUT (mV)
VIN – VOUT (V)
40
0.2
–0.2
100
6
60
RL = 50Ω
0.4
75
80
RL = 100Ω
0.6
50
OFFSET VOLTAGE vs TEMPERATURE
1.0
0.8
25
Temperature (°C)
Load Resistance (Ω)
2
4
6
8
10
–50
Input Voltage (V)
–25
0
25
50
75
100
125
Temperature (°C)
TOTAL HARMONIC DISTORTION vs FREQUENCY
TOTAL HARMONIC DISTORTION vs OUTPUT VOLTAGE
0.06
1.0
0.05
VO = 1Vrms
RL = 100Ω
0.04
THD (%)
THD (%)
0.1
f = 1kHz
RL = 100Ω
0.03
0.02
0.01
0.01
0
0.001
0
0.5
1.0
1.5
2.0
2.5
100
3.0
Output Voltage (Vrms)
1k
10k
100k
Frequency (Hz)
®
5
OPA633
APPLICATIONS INFORMATION
input voltage versus frequency curves. When used to buffer
an op amp’s output, the input to the OPA633 is limited, in
most cases, by the op amp. When high frequency inputs can
exceed safe levels, the device must be protected by limiting
the power supply current.
As with any high frequency circuitry, good circuit layout
technique must be used to achieve optimum performance.
Power supply connections must be bypassed with high
frequency capacitors. Many applications benefit from the
use of two capacitors on each power supply—a ceramic
capacitor for good high frequency decoupling and a tantalum type for lower frequencies. They should be located as
close as possible to the buffer’s power supply pins. A large
ground plane is used to minimize high frequency ground
drops and stray coupling.
PROTECTION CIRCUITS
The OPA633 can be protected from damage due to excessive currents by the simple addition of resistors in series with
the power supply pins (Figure 5a). While this limits output
current, it also limits voltage swing with low impedance
loads. This reduction in voltage swing is minimal for AC or
high crest factor signals since only the average current from
the power supply causes a voltage drop across the series
resistor. Short duration load-current peaks are
supplied by the bypass capacitors.
Pin 6 connects to the substrate of the integrated circuit and
should be connected to ground. In principle it could also be
connected to +VS or –VS, but ground is preferable. The
additional lead length and capacitance associated with sockets may cause problems in applications requiring the highest
fidelity of high speed pulses.
The circuit of Figure 5b overcomes the limitations of the
previous circuit with DC loads. It allows nearly full output
voltage swing up to its current limit of approximately 140mA.
Both circuits require good high frequency capacitors (e.g.,
tantalum) to bypass the buffer’s power supply connections.
Depending on the nature of the input source impedance, a
series input resistor may be required for best stability. This
behavior is influenced somewhat by the load impedance
(including any reactive effects). A value of 50Ω to 200Ω is
typical. This resistor should be located close to the OPA633’s
input pin to avoid stray capacitance at the input which could
reduce bandwidth (see Gain and Phase versus Frequency
curve).
CAPACITIVE LOADS
The OPA633 is designed to safely drive capacitive loads up
to 0.01µF. It must be understood, however, that rapidly
changing voltages demand large output load currents:
OVERLOAD CONDITIONS
The input and output circuitry of the OPA633 are not
protected from overload. When the input signal and load
characteristics are within the devices’s capabilities, no protection circuitry is required. Exceeding device limits can
result in permanent damage.
ILOAD = CLOAD
Thus, a signal slew rate of 1000V/µs and load capacitance of
0.01µF demands a load current of 10A. Clearly maximum
slew rates cannot be combined with large capacitive loads.
Load current should be kept less than 100mA continuous
(200mA peak) by limiting the rate of change of the input
signal or reducing the load capacitance.
The OPA633’s small package and high output current capability can lead to overheating. The internal junction temperature should not be allowed to exceed 150°C. Although
failure is unlikely to occur until junction temperature
exceeds 200°C, reliability of the part will be degraded
significantly at such high temperatures. Since significant
heat transfer takes place through the package leads, wide
printed circuit traces to all leads will improve heat sinking.
Sockets reduce heat transfer significantly and are not recommended.
USE INSIDE A FEEDBACK LOOP
The OPA633 may be used inside the feedback path of an op
amp such as the OPA602. Higher output current is achieved
without degradation in accuracy. This approach may actually improve performance in precision applications by removing load-dependent dissipation from a precision op amp.
All vestiges of load-dependent offset voltage and temperature drift can be eliminated with this technique. Since the
buffer is placed within the feedback loop of the op amp, its
DC errors will have a negligible effect on overall accuracy.
Any DC errors contributed by the buffer are divided by the
loop gain of the op amp.
Junction temperature rise is proportional to internal power
dissipation. This can be reduced by using the minimum
supply voltage necessary to produce the required output
voltage swing. For instance, 1V video signals can be easily
handled with ±5V power supplies thus minimizing the
internal power dissipation.
The low phase shift of the OPA633 allows its use inside the
feedback loop of a wide variety of op amps. To assure
stability, the buffer must not add significant phase shift to
the loop at the gain crossing frequency of the circuit—the
frequency at which the open loop gain of the op amp is equal
to the closed loop gain of the application. The OPA633 has
a typical phase shift of less than 10° up to 70MHz, thus
making it useful even with wideband op amps.
Output overloads or short circuits can result in permanent
damage by causing excessive output current. The 50Ω or
75Ω series output resistor used to match line impedance
will, in most cases, provide adequate protection. When this
resistor is not used, the device can be protected by limiting
the power supply current. See “Protection Circuits.”
Excessive input levels at high frequency can cause increased
internal dissipation and permanent damage. See the safe
®
OPA633
dV
dt
6
+12V
+15V
C1
0.1µF
R2
50Ω
R1
180Ω
VIN
RG-58
OPA633
C4
0.1µF
VIN
Coaxial Cable
R10
50Ω
Pulse
Generator
50Ω
C1
0.1µF
VOUT
OPA633
R5
50Ω
Termination
C4
0.1µF
R10
RL
–15V
–12V
POSITIVE PULSE RESPONSE
LARGE SIGNAL RESPONSE
10V STEP — RL = 1kΩ
100mV
VIN
0
10V
50mV
VIN
VOUT
0
0
10V
VOUT
0
NEGATIVE PULSE RESPONSE
10ns/div
10V STEP — RL = 100kΩ
0
VIN
–100mV
10V
0
VIN
VOUT
0
–50mV
10V
VOUT
0
FIGURE 1. Coaxial Cable Driver Circuit.
10ns/div
SMALL SIGNAL RESPONSE
0.5V STEP — RL = 1kΩ
0.5V
VIN
0
0.5V
VOUT
0
FIGURE 2. Dynamic Response Test Circuit.
®
7
OPA633
R9
10kΩ
R9
1kΩ
C5
500pF
R4
1kΩ
R8
150Ω
OPA602
C5
50pF
R8
150Ω
OPA602
OPA633
OPA633
G = –10
FIGURE 3. Precision High Current Buffer.
FIGURE 4. Buffered Inverting Amplifier.
+VS
4.7Ω
+VS
(a)
(b)
100Ω
1µF
1µF
2.7kΩ
+
Input
OPA633
Tantalum
+
Output
OPA633
Input
1µF
+
Tantalum
Output
1µF
+
Tantalum
Tantalum
100Ω
–VS
4.7Ω
–VS
FIGURE 5. Output Protection Circuits.
The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN
assumes no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject
to change without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not
authorize or warrant any BURR-BROWN product for use in life support devices and/or systems.
®
OPA633
8
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accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent
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