FEATURES
■
Gain-Bandwidth: 150MHz
■
Gain of 4 Stable
■
Slew Rate: 250V/µs
■
Input Noise Voltage: 6nV/√Hz
■
C-LoadTM Op Amp Drives Capacitive Loads
■
Maximum Input Offset Voltage: 600µV
■
Maximum Input Bias Current: 300nA
■
Maximum Input Offset Current: 300nA
■
Minimum Output Swing Into 500Ω: ±12V
■
Minimum DC Gain: 50V/mV, RL = 500Ω
■
Settling Time to 0.1%: 65ns, 10V Step
■
Settling Time to 0.01%: 85ns, 10V Step
■
Differential Gain: 0.08%, AV = 4, RL = 150Ω
■
Differential Phase: 0.2°, AV = 4, RL = 150Ω
U
APPLICATIO S
■
Wideband Amplifiers
■
Buffers
■
Active Filters
■
Video and RF Amplification
■
Cable Drivers
■
8-, 10-, 12-Bit Data Acquisition Systems
LT1221
150MHz, 250V/µs, AV ≥ 4
Operational Amplifier
U
DESCRIPTIO
The LT®1221 is a very high speed operational amplifier
with superior DC performance. The LT1221 is stable in a
noise gain of 4 or greater. It features reduced input offset
voltage, lower input bias currents and higher DC gain than
devices with comparable bandwidth and slew rate. The
circuit is a single gain stage that includes proprietary DC
gain enhancement circuitry to obtain precision with high
speed. The high gain and fast settling time make the circuit
an ideal choice for data acquisition systems. The circuit is
also capable of driving capacitive loads which makes it
useful in buffer or cable driver applications.
The LT1221 is a member of a family of fast, high performance amplifiers that employ Linear Technology
Corporation’s advanced complementary bipolar processing. For unity-gain stable applications the LT1220 can be
used, and for gains of 10 or greater the LT1222 can be used.
, LTC and LT are registered trademarks of Linear Technology Corporation
C-Load is a trademark of Linear Technology Corporation
TYPICAL APPLICATIO
Summing Amplifier
1k
V
A
1k
V
B
1k
V
C
1k
–
LT1221
+
U
V
OUT
LT1221 • TA01
Summing Amplifier Large-Signal Response
VS = ±15V
= 10V
V
IN
f = 2MHz
P-P
LT1221 • TA02
1
LT1221
A
W
O
LUTEXI TIS
S
A
WUW
U
(Note 1)
ARB
G
Total Supply Voltage (V+ to V–) ............................. 36V
Differential Input Voltage ........................................ ±6V
Input Voltage .......................................................... ±V
Output Short-Circuit Duration (Note 2)........... Indefinite
Specified Temperature Range
LT1221C (Note 3)................................... 0°C to 70°C
LT1221M (OBSOLETE) ............... –55°C to 125°C
WU
/
+IN
1
2
3
H PACKAGE
= 175°C, θ
O
RDER I FOR ATIO
TOP VIEW
NULL
8
4
–
V
JA
+
V
7
6
5
NC
= 150°C/W
V
OUT
ORDER PART
NUMBER
SPECIAL
ORDER
CONSULT
FACTORY
PACKAGE
NULL
–IN
8-LEAD TO-5 METAL CAN
T
JMAX
Operating Temperature Range
LT1221C........................................... –40°C TO 85°C
S
LT1221M (OBSOLETE) ............... –55°C to 125°C
Maximum Junction Temperature (See Below)
Plastic Package ............................................... 150°C
Ceramic Package (OBSOLETE) .................. 175°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
U
NULL
1
–IN
2
+IN
3
–
V
4
N8 PACKAGE
8-LEAD PLASTIC DIP
T
= 150°C, θ
JMAX
T
= 150°C, θ
JMAX
J8 PACKAGE
8-LEAD CERAMIC DIP
T
= 175°C, θ
JMAX
TOP VIEW
8
7
6
5
S8 PACKAGE
8-LEAD PLASTIC SOIC
= 130°C/W (N)
JA
= 190°C/W (S)
JA
= 100°C/W (J)
JA
NULL
+
V
V
OUT
NC
ORDER PART
NUMBER
LT1221CN8
LT1221CS8
S8 PART MARKING
1221
ORDER PART
NUMBER
OBSOLETE PACKAGE
Consider the N8 or S8 Package for Alternate Source
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
I
OS
I
B
e
n
i
n
R
IN
C
IN
CMRR Common Mode Rejection Ratio VCM = ±12V 92 114 dB
PSRR Power Supply Rejection Ratio VS = ±5V to ±15V 90 110 dB
A
VOL
V
OUT
I
OUT
SR Slew Rate (Note 5) 200 250 V/µs
GBW Gain-Bandwidth f = 1MHz 150 MHz
Input Offset Voltage (Note 4) 200 600 µV
Input Offset Current 100 300 nA
Input Bias Current 100 300 nA
Input Noise Voltage f = 10kHz 6 nV/√Hz
Input Noise Current f = 10kHz 2 pA/√Hz
Input Resistance VCM = ±12V 20 45 MΩ
Differential 80 kΩ
Input Capacitance 2pF
Input Voltage Range (Positive) 12 14 V
Input Voltage Range (Negative) –13 – 12 V
Large-Signal Voltage Gain V
Output Swing RL = 500Ω 12 13 ±V
Output Current V
Full Power Bandwidth 10V Peak (Note 6) 4 MHz
TA = 25°C, VS = ±15V, TA = 25°C, VCM = 0V, unless otherwise specified.
= ±10V, RL = 500Ω 50 100 V/mV
OUT
= ±12V 24 26 mA
OUT
OBSOLETE PACKAGE
Consider the N8 Package for Alternate Source
LT1221MJ8
2
LT1221
ELECTRICAL CHARACTERISTICS
VS = ±15V, TA = 25°C, VCM = 0V, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
tr, t
f
Rise Time, Fall Time AV = 4, 10% to 90%, 0.1V 3.2 ns
Overshoot AV = 4, 0.1V 10 %
Propagation Delay AV = 4, 50% VIN to 50% V
t
s
Settling Time 10V Step, 0.1% 65 ns
, 0.1V 5.4 ns
OUT
10V Step, 0.01% 85 ns
Differential Gain f = 3.58MHz, RL = 150Ω (Note 7) 0.08 %
f = 3.58MHz, R
= 1k (Note 7) 0.02 %
L
Differential Phase f = 3.58MHz, RL = 150Ω (Note 7) 0.20 DEG
f = 3.58MHz, RL = 1k (Note 7) 0.05 DEG
R
O
I
S
Output Resistance AV = 4, f = 1MHz 0.3 Ω
Supply Current 8 10.5 mA
The ● denotes the specifications which apply over the temperature range 0°C ≤ TA ≤ 70°C, otherwise specifications are at TA = 25°C.
VS = ±15V, VCM = 0V, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
Input Offset Voltage (Note 4) ● 0.2 1.5 mV
Input VOS Drift ● 15 µV/°C
I
OS
I
B
Input Offset Current ● 100 400 nA
Input Bias Current ● 100 400 nA
CMRR Common Mode Rejection Ratio VCM = ±12V ● 92 114 dB
PSRR Power Supply Rejection Ratio VS = ±5V to ±15V ● 90 110 dB
A
V
I
VOL
OUT
OUT
Large-Signal Voltage Gain V
= ±10V, RL = 500Ω ● 40 100 V/mV
OUT
Output Swing RL = 500Ω ● 12 13 ±V
Output Current V
= ±12V ● 24 26 mA
OUT
SR Slew Rate (Note 5) ● 180 250 V/µs
I
S
Supply Current ● 811 mA
The ● denotes the specifications which apply over the temperature range –55°C ≤ TA ≤ 125°C, otherwise specifications are at
TA = 25°C. VS = ±15V, VCM = 0V, unless otherwise specified.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
V
OS
I
OS
I
B
CMRR Common Mode Rejection Ratio VCM = ±12V ● 92 114 dB
PSRR Power Supply Rejection Ratio VS = ±5V to ±15V ● 90 110 dB
A
VOL
V
OUT
I
OUT
SR Slew Rate (Note 5) ● 130 250 V/µs
I
S
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: A heat sink may be required when the output is shorted indefinitely.
Note 3: Commercial parts are designed to operate over –40°C to 85°C, but
are not tested nor guaranteed beyond 0°C to 70°C. Industrial grade parts
specified and tested over –40°C to 85°C are available on special request.
Consult factory.
Input Offset Voltage (Note 4) ● 0.2 2 mV
Input VOS Drift ● 15 µV/°C
Input Offset Current ● 100 800 nA
Input Bias Current ● 100 1000 nA
Large-Signal Voltage Gain V
= ±10V, RL = 500Ω ● 12.5 100 V/mV
OUT
Output Swing RL = 500Ω ● 10 13 ±V
RL = 1k ● 12 13 ±V
Output Current V
= ±10V ● 20 26 mA
OUT
= ±12V ● 12 13 mA
V
OUT
Supply Current ● 811 mA
Note 4: Input offset voltage is pulse tested and is exclusive of warm-up drift.
Note 5: Slew rate is measured between ±10V on an output swing of ±12V.
Note 6: FPBW = SR/2πV
.
P
Note 7: Differential Gain and Phase are tested in AV = 4 with five amps in
series. Attenuators of 1/4 are used as loads (36.5Ω, 110Ω and
249Ω, 750Ω).
3
LT1221
FREQUENCY (Hz)
100
0
POWER SUPPLY REJECTION RATIO (dB)
10
20
40
60
80
100
1k 100k 10M 100M
LT1221 • TPC09
10k 1M
VS = ±15V
T
A
= 25°C
–PSRR
+PSRR
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
Input Common Mode Range
vs Supply Voltage
20
TA = 25°C
= 0.5mV
∆V
OS
15
10
5
MAGNITUDE OF INPUT VOLTAGE (V)
0
0
5101520
SUPPLY VOLTAGE (±V)
+V
–V
Output Voltage Swing
vs Resistive Load
30
TA = 25°C
= 30mV
∆V
P-P
OS
25
20
±15V SUPPLIES
15
10
5
0
10
LOAD RESISTANCE (Ω)
±5V SUPPLIES
100 1k 10k
)
OUTPUT VOLTAGE SWING (V
CM
CM
LT1221 • TPC01
LT1221 • TPC04
Supply Current vs Supply Voltage
and Temperature
11
10
T = 125°C
9
8
7
SUPPLY CURRENT (mA)
6
5
0
5101520
SUPPLY VOLTAGE (±V)
T = 25°C
T = –55°C
Input Bias Current
vs Input Common Mode Voltage
500
TA = 25°C
400
= ±15V
V
S
300
200
100
0
–100
–200
INPUT BIAS CURRENT (nA)
–300
–400
–500
–10 –5 10
–15
INPUT COMMON MODE VOLTAGE (V)
+
I
B
–
I
B
05 15
LT1221 • TPC02
LT1221 • TPC05
Output Voltage Swing
vs Supply Voltage
20
TA = 25°C
= 500Ω
R
L
= 30mV
∆V
OS
15
+V
10
–V
SW
5
MAGNITUDE OF OUTPUT VOLATGE (V)
0
0
5101520
SUPPLY VOLTAGE (±V)
Open-Loop Gain
vs Resistive Load
110
TA = 25°C
100
VS = ±15V
90
80
OPEN-LOOP GAIN (dB)
70
60
10
100 1k 10k
LOAD RESISTANCE (Ω)
SW
LT1221 • TPC03
VS = ±5V
LT1221 • TPC06
Output Short-Circuit Current
vs Temperature
50
VS = ±5V
45
40
35
30
25
OUTPUT SHORT-CIRCUIT CURRENT (mA)
20
4
–50
025 75
–25 50 100 125
TEMPERATURE (°C)
LT1221 • TPC07
Input Noise Spectral Density
1000
100
10
INPUT NOISE VOLTAGE (nV/√Hz)
1
10 1k 10k 100k
100
i
n
e
n
FREQUENCY (Hz)
VS = ±15V
T
A
R
= 25°C
A
= 101
V
= 100k
S
LT1221 • TPC08
Power Supply Rejection Ratio
vs Frequency
100
INPUT NOISE CURRENT (pA/√Hz)
10
1
0.1
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
LT1221
Common Mode Rejection Ratio
vs Frequency
120
100
80
60
40
20
COMMON MODE REJECTION RATIO (dB)
0
1k
10k
FREQUENCY (Hz)
1M
100k 10M 100M
Voltage Gain and Phase
vs Frequency
100
80
60
VS = ±15V
40
20
VOLTAGE GAIN (dB)
0
TA = 25°C
–20
100
1k
10k 1M 100M
FREQUENCY (Hz)
VS = ±5V
VS = ±5V
100k
VS = ±15V
= 25°C
T
A
LT1221 • TPC10
VS = ±15V
10M
LT1221 • TPC13
10
8
6
4
2
0
–2
OUTPUT SWING (V)
–4
–6
–8
–10
100
80
PHASE MARGIN (DEG)
60
40
20
0
–20
VOLTAGE MAGNITUDE (dB)
Output Swing and Error
vs Settling Time (Noninverting)
VS = ±15V
= 25°C
T
A
10mV
10mV
25
0
SETTLING TIME (ns)
1mV
1mV
75
50
100
LT1220 • TPC11
Frequency Response
vs Capacitive Load
24
VS = ±15V
22
= 25°C
T
A
= –5
A
V
20
18
16
14
12
10
C = 500pF
8
6
4
1
C = 1000pF
FREQUENCY (MHz)
C = 100pF
C = 50pF
10
LT1221 • TPC14
125
C = 0
OUTPUT SWING (V)
OUTPUT IMPEDANCE (Ω)
0.001
100
Output Swing and Error
vs Settling Time (Inverting)
10
VS = ±15V
8
= 25°C
T
A
–2
–4
–6
–8
–10
6
4
2
0
10mV
10mV
25
0
SETTLING TIME (ns)
1mV
1mV
75
50
100
LT1221 • TPC12
Closed-Loop Output Impedance
vs Frequency
10
VS = ±15V
= 25°C
T
A
= 4
A
V
1
0.1
0.01
10k 1M 10M 100M
100k
FREQUENCY (Hz)
LT1221 • TPC15
125
Gain-Bandwidth vs Temperature
180
VS = ±15V
170
160
150
140
GAIN-BANDWIDTH (MHz)
130
120
–25 75
–50
25 50 100
0
TEMPERATURE (°C)
LT1221 • TPC16
125
Slew Rate vs Temperature
325
VS = ±15V
= –5
A
V
300
275
250
225
SLEW RATE (V/µs)
200
175
–50
+
(SR
) + (SR–)
SR =
2
0
–25 75
25 50 100
TEMPERATURE (°C)
LT1221 • TPC19
Total Harmonic Distortion
vs Frequency
0.01
VS = ±15V
V
= 3V
O
RMS
Ω
RL = 500
0.001
0.0001
TOTAL HARMONIC DISTORTION AND NOISE (%)
125
10 100
FREQUENCY (Hz)
AV = 4
AV = –4
1k 10k 100k
LT1220 • TPC18
5
LT1221
W
U
TYPICAL PERFORMANCE CHARACTERISTICS
Small Signal, AV = 4
Large Signal, AV = 4
Large Signal, AV = 4,
CL = 10,000pF
VS = ±15V
V
= 25mV
IN
f = 5MHz
Small Signal, AV = –4
VS = ±15V
= 25mV
V
IN
f = 5MHz
LT1221 • TPC19
LT1221 • TPC22
U
VS = ±15V
V
= 5V
IN
Large Signal, AV = –4
VS = ±15V
= 5V
V
IN
WUU
f = 2MHz
P-P
f = 2MHz
P-P
APPLICATIONS INFORMATION
The LT1221 is stable in noise gains of 4 or greater and may
be inserted directly into HA2520/2/5, HA2541/2/4, AD817,
AD847, EL2020, EL2044 and LM6361 applications, provided that the nulling circuitry is removed and the amplifier configuration has a high enough noise gain. The
suggested nulling circuit for the LT1221 is shown in the
following figure.
Offset Nulling
+
V
5k
1
3
2
+
LT1221
–
8
7
4
–
V
0.1µF
6
0.1µF
LT1221 • AI01
LT1221 • TPC20
V
S
V
IN
= ±15V
= 5V
P-P
f = 20kHz
LT1221 • TPC21
Small Signal, AV = –4,
CL = 1,000pF
LT1221 • TPC23 LT1221 • TPC24
V
S
V
IN
= ±15V
= 42mV
f = 500kHz
Layout and Passive Components
The LT1221 amplifier is easy to apply and tolerant of less
than ideal layouts. For maximum performance (for example, fast settling time) use a ground plane, short lead
lengths and RF-quality bypass capacitors (0.01µF to 0.1µF).
For high drive current applications use low ESR bypass
capacitors (1µF to 10µF tantalum). Sockets should be
avoided when maximum frequency performance is required, although low profile sockets can provide reasonable performance up to 50MHz. For more details see
Design Note 50. Feedback resistors greater than 5k are not
recommended because a pole is formed with the input
capacitance which can cause peaking or oscillations.
Input Considerations
Bias current cancellation circuitry is employed on the
inputs of the LT1221 so the input bias current and input
6
LT1221
U
WUU
APPLICATIONS INFORMATION
offset current have identical specifications. For this reason,
matching the impedance on the inputs to reduce bias
current errors is not necessary.
Capacitive Loading
The LT1221 is stable with capacitive loads. This is accomplished by sensing the load induced output pole and adding
compensation at the amplifier gain node. As the capacitive
load increases, both the bandwidth and phase margin
decrease. There will be peaking in the frequency domain as
shown in the curve of Frequency Response vs Capacitive
Load. The small-signal transient response will have more
overshoot as shown in the photo of the small-signal
response with 1000pF load. The large-signal response with
a 10,000pF load shows the output slew rate being limited
to 4V/µs by the short-circuit current. The LT1221 can drive
coaxial cable directly, but for best pulse fidelity a resistor of
value equal to the characteristic impedance of the cable
(i.e., 75Ω) should be placed in series with the output. The
other end of the cable should be terminated with the same
value resistor to ground.
Compensation
The LT1221 has a typical gain-bandwidth product of
150MHz which allows it to have wide bandwidth in high
gain configurations (i.e., in a gain of 10, it will have a
bandwidth of about 15MHz). The amplifier is stable in a
noise gain of 4 so the ratio of the signal at the inverting input
to the output must be 1/4 or less. Straightforward gain
configurations of 4 or –3 are stable, but there are several
others that allow the amplifier to be stable for lower signal
gains (the noise gain, however, remains 4 or more). One
example is the summing amplifier on the first page of this
data sheet. Each input signal has a gain of –1 to the output,
but it is easily seen that this configuration is equivalent to
a gain of –3 as far as the amplifier is concerned. Another
circuit is shown below with a DC gain of 1, but an AC gain
of 5. The break frequency of the R-C combination across
the amplifier inputs should be approximately a factor of 10
less than the gain-bandwidth of the amplifier divided by the
high frequency gain (in this case 1/10 of 150MHz/5 or
3MHz).
WW
SI PLIFIED SCHE ATIC
+
7V
NULL
18
+IN 3
–
V
4
–IN
2
BIAS 2BIAS 1
6 OUT
LT1221 • SS
7
LT1221
PACKAGE DESCRIPTIO
0.040
(1.016)
MAX
SEATING
PLANE
0.010 – 0.045*
(0.254 – 1.143)
U
H Package
8-Lead TO-5 Metal Can (.200 Inch PCD)
(Reference LTC DWG # 05-08-1320)
0.335 – 0.370
(8.509 – 9.398)
DIA
0.305 – 0.335
(7.747 – 8.509)
0.016 – 0.021**
(0.406 – 0.533)
0.050
(1.270)
MAX
GAUGE
PLANE
0.165 – 0.185
(4.191 – 4.699)
0.500 – 0.750
(12.700 – 19.050)
REFERENCE
PLANE
45°TYP
0.028 – 0.034
(0.711 – 0.864)
0.110 – 0.160
(2.794 – 4.064)
INSULATING
STANDOFF
0.027 – 0.045
(0.686 – 1.143)
PIN 1
0.200
(5.080)
TYP
*
LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND 0.045" BELOW THE REFERENCE PLANE
**
FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS
OBSOLETE PACKAGE
0.016 – 0.024
(0.406 – 0.610)
H8(TO-5) 0.200 PCD 1197
8
PACKAGE DESCRIPTIO
LT1221
U
J8 Package
8-Lead CERDIP (Narrow .300 Inch, Hermetic)
(Reference LTC DWG # 05-08-1110)
CORNER LEADS OPTION
(4 PLCS)
0.023 – 0.045
(0.584 – 1.143)
HALF LEAD
0.045 – 0.068
(1.143 – 1.727)
FULL LEAD
OPTION
0.300 BSC
(0.762 BSC)
0.008 – 0.018
(0.203 – 0.457)
NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE
OR TIN PLATE LEADS
0° – 15°
OPTION
0.005
(0.127)
MIN
0.025
(0.635)
RAD TYP
0.045 – 0.065
(1.143 – 1.651)
0.014 – 0.026
(0.360 – 0.660)
0.405
(10.287)
MAX
87
12
65
3
4
0.220 – 0.310
(5.588 – 7.874)
0.015 – 0.060
(0.381 – 1.524)
0.100
(2.54)
BSC
0.200
(5.080)
MAX
0.125
3.175
MIN
J8 1298
OBSOLETE PACKAGE
9
LT1221
PACKAGE DESCRIPTIO
U
N8 Package
8-Lead PDIP (Narrow .300 Inch)
(Reference LTC DWG # 05-08-1510)
0.255 ± 0.015*
(6.477 ± 0.381)
0.400*
(10.160)
MAX
876
5
12
0.300 – 0.325
(7.620 – 8.255)
0.065
(1.651)
0.009 – 0.015
(0.229 – 0.381)
+0.035
0.325
–0.015
+0.889
8.255
()
–0.381
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.100
(2.54)
BSC
3
4
0.130 ± 0.005
(3.302 ± 0.127)
0.125
(3.175)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.020
(0.508)
MIN
N8 1098
10
PACKAGE DESCRIPTIO
U
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
0.189 – 0.197*
(4.801 – 5.004)
7
8
6
LT1221
5
0.228 – 0.244
(5.791 – 6.197)
0.010 – 0.020
(0.254 – 0.508)
0.008 – 0.010
(0.203 – 0.254)
*
DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**
DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
× 45°
(1.346 – 1.752)
0°– 8° TYP
0.016 – 0.050
(0.406 – 1.270)
0.053 – 0.069
0.014 – 0.019
(0.355 – 0.483)
TYP
0.150 – 0.157**
(3.810 – 3.988)
SO8 1298
1
3
2
4
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
11
LT1221
TYPICAL APPLICATIO S
20MHz, AV = 50 Instrumentation Amplifier
+
V
IN
–
200pF
250Ω
250Ω
+
LT1221
–
1k
1k
–
LT1221
+
U
1k
1k
10k
+
LT1221
–
10k
LT1221 • TA03
Lag Compensation
V
IN
500Ω
+
LT1221
V
OUT
–
100pF
V
OUT
A
= 1, f < 3MHz
V
2k
LT1221 • TA04
Cable Driver
V
+
IN
LT1221
–
1.5k
75Ω
75Ω CABLE
75Ω
V
OUT
510Ω
RELATED PARTS
PART NUMBER DESCRIPTION COMMENTS
LT1220 45MHz, 250V/µs Amplifier Unity Gain Stable Version of the LT1221
LT1222 500MHz, 200V/µs Amplifier AV ≥ 10 Version of the LT1221
LT1221 • TA05
12
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
1221fb LT/CP 0901 1.5K REV B • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1992
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