Scheda tecnica LT1361, LT1362 di Analog Devices Inc.

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1
LT1361/LT1362
■
50MHz Gain Bandwidth
■
800V/µs Slew Rate
■
5mA Maximum Supply Current per Amplifier
■
Unity-Gain Stable
■
C-Load
TM
Op Amp Drives All Capacitive Loads
■
9nV/√Hz Input Noise Voltage
■
1mV Maximum Input Offset Voltage
■
1µA Maximum Input Bias Current
■
250nA Maximum Input Offset Current
■
±13V Minimum Output Swing into 500Ω
■
±3.2V Minimum Output Swing into 150Ω
■
4.5V/mV Minimum DC Gain, R
L
=1k
■
60ns Settling Time to 0.1%, 10V Step
■
0.2% Differential Gain, A
V
=2, R
L
=150Ω
■
0.3° Differential Phase, A
V
=2, R
L
=150Ω
■
Specified at ±2.5V, ±5V, and ±15V
Dual and Quad
50MHz, 800V/µs Op Amps
The LT1361/LT1362 are dual and quad low power high
speed operational amplifiers with outstanding AC and DC
performance. The amplifiers feature much lower supply
current and higher slew rate than devices with comparable
bandwidth. The circuit topology is a voltage feedback
amplifier with matched high impedance inputs and the
slewing performance of a current feedback amplifier. The
high slew rate and single stage design provide excellent
settling characteristics which make the circuit an ideal
choice for data acquisition systems. Each output drives a
500Ω load to ±13V with ±15V supplies and a 150Ω load to
±3.2V on ±5V supplies. The amplifiers are stable with any
capacitive load making them useful in buffer or cable
driving applications.
The LT1361/LT1362 are members of a family of fast, high
performance amplifiers using this unique topology and
employing Linear Technology Corporation’s advanced
bipolar complementary processing. For a single amplifier
version of the LT1361/LT1362 see the LT1360 data sheet.
For higher bandwidth devices with higher supply currents
see the LT1363 through LT1365 data sheets. For lower
supply current amplifiers see the LT1354 to LT1359 data
sheets. Singles, duals, and quads of each amplifier are
available.
■
Wideband Amplifiers
■
Buffers
■
Active Filters
■
Video and RF Amplification
■
Cable Drivers
■
Data Acquisition Systems
Cable Driver Frequency Response
1361/1362 TA02
AV = –1 Large-Signal Response
C-Load is a trademark of Linear Technology Corporation
FREQUENCY (MHz)
1
–8
–6
–4
–2
0
GAIN (dB)
2
100
1361/1362 TA01
10
V
S
= ±10V
V
S
= ±5V
V
S
= ±2.5V
V
S
= ±15V
–
+
1/2
LT1361
510Ω
75ΩOUT
75Ω
IN
510Ω
APPLICATIO S
U
FEATURES
TYPICAL APPLICATIO
U
DESCRIPTIO
U
, LTC and LT are registered trademarks of Linear Technology Corporation.
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2
LT1361/LT1362
SYMBOL PARAMETER CONDITIONS V
SUPPLY
MIN TYP MAX UNITS
V
OS
Input Offset Voltage (Note 4) ±15V 0.3 1.0 mV
±5V 0.3 1.0 mV
±2.5V 0.4 1.2 mV
I
OS
Input Offset Current ±2.5V to ±15V 80 250 nA
I
B
Input Bias Current ±2.5V to ±15V 0.3 1.0 µA
e
n
Input Noise Voltage f = 10kHz ±2.5V to ±15V 9 nV/√Hz
i
n
Input Noise Current f = 10kHz ±2.5V to ±15V 0.9 pA/√Hz
R
IN
Input Resistance V
CM
= ±12V ±15V 20 50 MΩ
Input Resistance Differential ±15V 5 MΩ
C
IN
Input Capacitance ±15V 3 pF
Total Supply Voltage (V
+
to V
–
)............................... 36V
Differential Input Voltage
(Transient Only) (Note 2)................................... ±10V
Input Voltage ............................................................±V
S
Output Short-Circuit Duration (Note 3)............ Indefinite
ABSOLUTE MAXIMUM RATINGS
W
WW
U
Operating Temperature Range (Note 8) ...–40°C to 85°C
Specified Temperature Range (Note 9)....–40°C to 85°C
Maximum Junction Temperature (See Below)
Plastic Package ................................................ 150°C
Storage Temperature Range ..................–65°C to 150°C
Lead Temperature (Soldering, 10 sec)..................300°C
PACKAGE/ORDER INFORMATION
W
UU
ORDER PART
NUMBER ORDER PART
NUMBER
T
JMAX
= 150°C, θ
JA
= 190°C/ WT
JMAX
= 150°C, θ
JA
= 130°C/ W
LT1361CS8
S8 PART MARKING
1361
LT1361CN8
ORDER PART
NUMBER ORDER PART
NUMBER
LT1362CSLT1362CN
V+
D
14
13
12
11
10
9
87
6
5
4
3
2
1
OUT A
–IN A
+IN A
+IN B
–IN B
OUT B OUT C
V–
–IN D
OUT D
TOP VIEW
A+IN D
+IN C
–IN C
C
B
N PACKAGE
14-LEAD PDIP
V
+
D
16
15
14
13
12
11
107
6
5
4
3
2
1
OUT A
–IN A
+IN A
+IN B
–IN B
OUT B OUT C
98
NC NC
V
–
–IN D
OUT D
TOP VIEW
A+IN D
+IN C
–IN C
C
B
S PACKAGE
16-LEAD PLASTIC SO
8
7
6
54
3
2
1
–IN A
+IN A
V+
TOP VIEW
S8 PACKAGE
8-LEAD PLASTIC SO
OUT A
OUT B
V–
–IN B
+IN B
A
B
8
7
6
54
3
2
1
–IN A
+IN A
V+
TOP VIEW
N8 PACKAGE
8-LEAD PDIP
OUT A
OUT B
V–
–IN B
+IN B
A
B
T
JMAX
= 150°C, θ
JA
= 150°C/ WT
JMAX
= 150°C, θ
JA
= 110°C/ W
TA = 25°C, VCM = 0V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
Consult factory for Industrial and Military grade parts.
(Note 1)
L7 WW
3
LT1361/LT1362
Input Voltage Range
+
±15V 12.0 13.4 V
±5V 2.5 3.4 V
±2.5V 0.5 1.1 V
Input Voltage Range
–
±15V –13.2 –12.0 V
±5V –3.2 –2.5 V
±2.5V –0.9 –0.5 V
CMRR Common Mode Rejection Ratio V
CM
= ±12V ±15V 86 92 dB
V
CM
= ±2.5V ±5V 79 84 dB
V
CM
= ±0.5V ±2.5V 68 74 dB
PSRR Power Supply Rejection Ratio V
S
= ±2.5V to ±15V 93 105 dB
A
VOL
Large-Signal Voltage Gain V
OUT
= ±12V, R
L
= 1k ±15V 4.5 9.0 V/mV
V
OUT
= ±10V, R
L
= 500Ω±15V 3.0 6.5 V/mV
V
OUT
= ±2.5V, R
L
= 500Ω±5V 3.0 6.4 V/mV
V
OUT
= ±2.5V, R
L
= 150Ω±5V 1.5 4.2 V/mV
V
OUT
= ±1V, R
L
= 500Ω±2.5V 2.5 5.2 V/mV
V
OUT
Output Swing R
L
= 1k, V
IN
= ±40mV ±15V 13.5 13.9 ±V
R
L
= 500Ω, V
IN
= ±40mV ±15V 13.0 13.6 ±V
R
L
= 500Ω, V
IN
= ±40mV ±5V 3.5 4.0 ±V
R
L
= 150Ω, V
IN
= ±40mV ±5V 3.2 3.8 ±V
R
L
= 500Ω, V
IN
= ±40mV ±2.5V 1.3 1.7 ±V
I
OUT
Output Current V
OUT
= ±13V ±15V 26 34 mA
V
OUT
= ±3.2V ±5V 21 29 mA
I
SC
Short-Circuit Current V
OUT
= 0V, V
IN
= ±3V ±15V 40 54 mA
SR Slew Rate A
V
= –2, (Note 5) ±15V 600 800 V/µs
±5V 250 350 V/µs
Full Power Bandwidth 10V Peak, (Note 6) ±15V 12.7 MHz
3V Peak, (Note 6) ±5V 18.6 MHz
GBW Gain Bandwidth f = 200kHz ±15V 35 50 MHz
±5V 25 37 MHz
±2.5V 32 MHz
t
r
, t
f
Rise Time, Fall Time A
V
= 1, 10%-90%, 0.1V ±15V 3.1 ns
±5V 4.3 ns
Overshoot A
V
= 1, 0.1V ±15V 35 %
±5V 27 %
Propagation Delay 50% V
IN
to 50% V
OUT
, 0.1V ±15V 5.2 ns
±5V 6.4 ns
t
s
Settling Time 10V Step, 0.1%, A
V
= –1 ±15V 60 ns
10V Step, 0.01%, A
V
= –1 ±15V 90 ns
5V Step, 0.1%, A
V
= –1 ±5V 65 ns
Differential Gain f = 3.58MHz, A
V
= 2, R
L
= 150Ω±15V 0.20 %
±5V 0.20 %
f = 3.58MHz, A
V
= 2, R
L
= 1k ±15V 0.04 %
±5V 0.02 %
Differential Phase f = 3.58MHz, A
V
= 2, R
L
= 150Ω±15V 0.40 Deg
±5V 0.30 Deg
f = 3.58MHz, A
V
= 2, R
L
= 1k ±15V 0.07 Deg
±5V 0.26 Deg
R
O
Output Resistance A
V
= 1, f = 1MHz ±15V 1.4 Ω
Channel Separation V
OUT
= ±10V, R
L
= 500Ω±15V 100 113 dB
I
S
Supply Current Each Amplifier ±15V 4.0 5.0 mA
Each Amplifier ±5V 3.8 4.8 mA
SYMBOL PARAMETER CONDITIONS V
SUPPLY
MIN TYP MAX UNITS
TA = 25°C, VCM = 0V unless otherwise noted.
ELECTRICAL CHARACTERISTICS
4
LT1361/LT1362
SYMBOL PARAMETER CONDITIONS V
SUPPLY
MIN TYP MAX UNITS
V
OS
Input Offset Voltage (Note 4) ±15V ●1.5 mV
±5V ●1.5 mV
±2.5V ●1.7 mV
Input V
OS
Drift (Note 7) ±2.5V to ±15V ●912 µV/°C
I
OS
Input Offset Current ±2.5V to ±15V ●350 nA
I
B
Input Bias Current ±2.5V to ±15V ●1.5 µA
CMRR Common Mode Rejection Ratio V
CM
= ±12V ±15V ●84 dB
V
CM
= ±2.5V ±5V ●77 dB
V
CM
= ±0.5V ±2.5V ●66 dB
PSRR Power Supply Rejection Ratio V
S
= ±2.5V to ±15V ●91 dB
A
VOL
Large-Signal Voltage Gain V
OUT
= ±12V, R
L
= 1k ±15V ●3.6 V/mV
V
OUT
= ±10V, R
L
= 500Ω±15V ●2.4 V/mV
V
OUT
= ±2.5V, R
L
= 500Ω±5V ●2.4 V/mV
V
OUT
= ±2.5V, R
L
= 150Ω±5V ●1.0 V/mV
V
OUT
= ±1V, R
L
= 500Ω±2.5V ●2.0 V/mV
V
OUT
Output Swing R
L
= 1k, V
IN
= ±40mV ±15V ●13.4 ±V
R
L
= 500Ω, V
IN
= ±40mV ±15V ●12.8 ±V
R
L
= 500Ω, V
IN
= ±40mV ±5V ●3.4 ±V
R
L
= 150Ω, V
IN
= ±40mV ±5V ●3.1 ±V
R
L
= 500Ω, V
IN
= ±40mV ±2.5V ●1.2 ±V
I
OUT
Output Current V
OUT
= ±12.8V ±15V ●25 mA
V
OUT
= ±3.1V ±5V ●20 mA
I
SC
Short-Circuit Current V
OUT
= 0V, V
IN
= ±3V ±15V ●32 mA
SR Slew Rate A
V
= –2, (Note 5) ±15V ●475 V/µs
±5V ●185 V/µs
GBW Gain Bandwidth f = 200kHz ±15V ●31 MHz
±5V ●22 MHz
Channel Separation V
OUT
= ±10V, R
L
= 500Ω±15V ●98 dB
I
S
Supply Current Each Amplifier ±15V ●5.8 mA
Each Amplifier ±5V ●5.6 mA
ELECTRICAL CHARACTERISTICS
SYMBOL PARAMETER CONDITIONS V
SUPPLY
MIN TYP MAX UNITS
V
OS
Input Offset Voltage (Note 4) ±15V ●2.0 mV
±5V ●2.0 mV
±2.5V ●2.2 mV
Input V
OS
Drift (Note 7) ±2.5V to ±15V ●912 µV/°C
I
OS
Input Offset Current ±2.5V to ±15V ●400 nA
I
B
Input Bias Current ±2.5V to ±15V ●1.8 µA
CMRR Common Mode Rejection Ratio V
CM
= ±12V ±15V ●84 dB
V
CM
= ±2.5V ±5V ●77 dB
V
CM
= ±0.5V ±2.5V ●66 dB
PSRR Power Supply Rejection Ratio V
S
= ±2.5V to ±15V ●90 dB
A
VOL
Large-Signal Voltage Gain V
OUT
= ±12V, R
L
= 1k ±15V ●2.5 V/mV
V
OUT
= ±10V, R
L
= 500Ω±15V ●1.5 V/mV
V
OUT
= ±2.5V, R
L
= 500Ω±5V ●1.5 V/mV
V
OUT
= ±2.5V, R
L
= 150Ω±5V ●0.6 V/mV
V
OUT
= ±1V, R
L
= 500Ω±2.5V ●1.3 V/mV
The ● denotes the specifications which apply over the temperature range –40°C ≤ TA ≤ 85°C, VCM = 0V unless otherwise noted. (Note 9)
The ● denotes the specifications which apply over the temperature range
0°C ≤ TA ≤ 70°C, VCM = 0V unless otherwise noted.
\ \ L7 WW
5
LT1361/LT1362
SYMBOL PARAMETER CONDITIONS V
SUPPLY
MIN TYP MAX UNITS
V
OUT
Output Swing R
L
= 1k, V
IN
= ±40mV ±15V ●13.4 ±V
R
L
= 500Ω, V
IN
= ±40mV ±15V ●12.0 ±V
R
L
= 500Ω, V
IN
= ±40mV ±5V ●3.4 ±V
R
L
= 150Ω, V
IN
= ±40mV ±5V ●3.0 ±V
R
L
= 500Ω, V
IN
= ±40mV ±2.5V ●1.2 ±V
I
OUT
Output Current V
OUT
= ±12.0V ±15V ●24 mA
V
OUT
= ±3.0V ±5V ●20 mA
I
SC
Short-Circuit Current V
OUT
= 0V, V
IN
= ±3V ±15V ●30 mA
SR Slew Rate A
V
= –2, (Note 5) ±15V ●450 V/µs
±5V ●175 V/µs
GBW Gain Bandwidth f = 200kHz ±15V ●30 MHz
±5V ●20 MHz
Channel Separation V
OUT
= ±10V, R
L
= 500Ω±15V ●98 dB
I
S
Supply Current Each Amplifier ±15V ●6.0 mA
Each Amplifier ±5V ●5.8 mA
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Input Common Mode Range vs
Supply Voltage
SUPPLY VOLTAGE (±V)
1
SUPPLY CURRENT (mA)
3
2
6
5
4
10501520
1361/1362 G01
–55°C
25°C
125°C
Supply Current vs Supply Voltage
and Temperature Input Bias Current vs
Input Common Mode Voltage
INPUT COMMON MODE VOLTAGE (V)
0
INPUT BIAS CURRENT (µA)
0.2
0.1
0.6
0.5
0.4
0.3
–15 –10 0 10 155–5
1361/1362 G03
V
S
= ±15V
T
A
= 25°C
I
B
=
I
B
+ + I
B
–
————
2
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2: Differential inputs of ±10V are appropriate for transient operation
only, such as during slewing. Large, sustained differential inputs will cause
excessive power dissipation and may damage the part. See Input
Considerations in the Applications Information section of this data sheet
for more details.
Note 3: A heat sink may be required to keep the junction temperature
below absolute maximum when the output is shorted indefinitely.
Note 4: Input offset voltage is pulse tested and is exclusive of warm-up drift.
Note 5: Slew rate is measured between ±10V on the output with ±6V input
for ±15V supplies and ±1V on the output with ±1.75V input for ±5V supplies.
Note 6: Full power bandwidth is calculated from the slew rate
measurement: FPBW = SR/2πV
P
.
Note 7: This parameter is not 100% tested.
Note 8: The LT1361C/LT1362C are guaranteed functional over the
operating temperature range of –40°C to 85°C.
Note 9: The LT1361C/LT1362C are guaranteed to meet specified
performance from 0°C to 70°C. The LT1361C/LT1362C are designed,
characterized and expected to meet specified performance from –40°C to
85°C, but are not tested or QA sampled at these temperatures. For
guaranteed I-grade parts, consult the factory.
SUPPLY VOLTAGE (±V)
V
–
COMMON MODE RANGE (V)
2.0
0.5
1.0
1.5
V
+
–1.0
–0.5
–2.0
–1.5
10501520
1361/1362 G02
T
A
= 25°C
∆V
OS
< 1mV
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the temperature range
–40°C ≤ TA ≤ 85°C, VCM = 0V unless otherwise noted. (Note 9)
6
LT1361/LT1362
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Settling Time vs Output Step
(Noninverting)
FREQUENCY (Hz)
10
1
INPUT VOLTAGE NOISE (nV/√Hz)
10 i
n
100
0.1
INPUT CURRENT NOISE (pA/√Hz)
1
10
e
n
1k100 100k10k
1361/1362 G05
V
S
= ±15V
T
A
= 25°C
A
V
= 101
R
S
= 100k
Open-Loop Gain vs
Resistive Load
TEMPERATURE (°C)
0
INPUT BIAS CURRENT (µA)
0.2
0.1
0.7
0.6
0.5
0.3
0.4
–50 –25 25 100 12550 750
1361/1362 G04
V
S
= ±15V
I
B
=
I
B
+ + I
B
–
————
2
Input Bias Current vs
Temperature Input Noise Spectral Density
Open-Loop Gain vs Temperature
TEMPERATURE (°C)
72
OPEN-LOOP GAIN (dB)
74
73
81
80
79
78
76
75
77
–50 –25 25 100 12550 750
1361/1362 G07
V
S
= ±15V
V
O
= ±12V
R
L
= 1k
Output Voltage Swing vs
Supply Voltage Output Voltage Swing vs
Load Current
TEMPERATURE (°C)
35
OUTPUT SHORT-CIRCUIT CURRENT (mA)
40
70
65
60
50
45
55
–50 –25 25 100 12550 750
1361/1362 G10
V
S
= ±5V
SOURCE
SINK
Output Short-Circuit Current vs
Temperature
LOAD RESISTANCE (Ω)
10
60
OPEN-LOOP GAIN (dB)
65
85
100 10k
1361/1362 G06
75
70
1k
80
V
S
= ±5V
V
S
= ±15V
T
A
= 25°C
SUPPLY VOLTAGE (±V)
V
–
OUTPUT VOLTAGE SWING (V)
1
2
3
V
+
–1
–3
–2
10501520
1361/1362 G08
R
L
= 1k
T
A
= 25°C
R
L
= 500Ω
R
L
= 500Ω
R
L
= 1k
OUTPUT CURRENT (mA)
OUTPUT VOLTAGE SWING (V)
1.0
1.5
0.5
V+
V–
–0.5
–1.0
–1.5
2.0
–2.0
–50 –40 –10 30 40 5001020–20–30
1361/1362 G09
VS = ±5V
VIN = 100mV 85°C
85°C
25°C
25°C
–40°C
–40°C
SETTLING TIME (ns)
–10
OUTPUT STEP (V)
–6
–4
–8
10
8
6
4
–2
2
0
0 40 80 1006020
1361/1362 G11
V
S
= ±15V
A
V
= 1
R
L
= 1k
10mV
10mV
1mV
1mV
SETTLING TIME (ns)
–10
OUTPUT STEP (V)
–6
–4
–8
10
8
6
4
–2
2
0
0 40 80 1006020
1361/1362 G12
V
S
= ±15V
A
V
= –1
R
F
= 1k
C
F
= 3pF
10mV
10mV
1mV
1mV
Settling Time vs Output Step
(Inverting)
PHASE SAW v5=fl5v 2 PHASE MARGW _\ GAW BANDWIDIH L7L'F1WEGB
7
LT1361/LT1362
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Output Impedance vs Frequency
Gain Bandwidth and Phase
Margin vs Temperature
TEMPERATURE (°C)
30
GAIN BANDWIDTH (MHz)
40
80
70
50
60
0
PHASE MARGIN (DEG)
5
10
50
45
35
40
20
25
15
30
–50 –25 25 100 12550 750
1361/1362 G16
PHASE MARGIN
VS = ±5V
GAIN BANDWIDTH
VS = ±5V
PHASE MARGIN
VS = ±15V
GAIN BANDWIDTH
VS = ±15V
FREQUENCY (Hz)
10k
0.01
OUTPUT IMPEDANCE (Ω)
0.1
100
100k 100M
1361/1362 G13
1M
1
10M
10 A
V
= 100 A
V
= 10
A
V
= 1
V
S
= ±15V
T
A
= 25°C
Common Mode Rejection Ratio
vs Frequency
FREQUENCY (Hz)
0
COMMON-MODE REJECTION RATIO (dB)
40
20
120
100
80
60
1k 100M10M1M100k10k
1361/1362 G20
V
S
= ±15V
T
A
= 25°C
Gain Bandwidth and Phase
Margin vs Supply Voltage
SUPPLY VOLTAGE (±V)
30
GAIN BANDWIDTH (MHz)
50
40
80
70
60
30
PHASE MARGIN (DEG)
38
34
50
48
44
40
36
32
46
42
10501520
1361/1362 G15
T
A
= 25°C
PHASE MARGIN
GAIN BANDWIDTH
FREQUENCY (Hz)
0
POWER SUPPLY REJECTION RATIO (dB)
40
20
100
80
60
100k 1M1k 10k100 10M 100M
1361/1362 G19
V
S
= ±15V
T
A
= 25°C
+PSRR
–PSRR
Frequency Response vs
Capacitive Load
FREQUENCY (Hz)
1M
–8
VOLTAGE MAGNITUDE (dB)
–4
–6
12
100M
1361/1362 G18
4
0
10M
8
–2
6
2
10 V
S
= ±15V
T
A
= 25°C
A
V
= –1
C = 1000pF
C = 500pF
C = 100pF
C = 50pF
C = 0
FREQUENCY (Hz)
100k
–120
CROSSTALK (dB)
–100
–110
–20
1M 100M
1361/1362 G21
–60
–80
10M
–40
–90
–50
–70
–30 T
A
= 25°C
A
V
= 1
V
IN
= 0dBm
V
S
= ±15V
R
L
= 1k
V
S
= ±5V
R
L
= 500Ω
Crosstalk vs Frequency
FREQUENCY (Hz)
10k
–10
GAIN (dB)
0
70
100k 100M
1361/1362 G14
1M
30
40
10
20
10M
50
60
PHASE (DEG)
120
40
60
0
20
80
100
V
S
= ±15V
V
S
= ±5V
V
S
= ±5V
GAIN V
S
= ±15V
PHASE
T
A
= 25°C
A
V
= –1
R
F
= R
G
= 1k
Gain and Phase vs Frequency
Power Supply Rejection Ratio
vs Frequency
FREQUENCY (Hz)
100k
–5
GAIN (dB)
–3
–4
5
1M 100M
1361/1362 G17
1
–1
10M
3
–2
2
0
4
±5V
±15V
±2.5V
TA = 25°C
AV = 1
RL = 1k
Frequency Response vs
Supply Voltage (AV = 1)
\
8
LT1361/LT1362
TYPICAL PERFORMANCE CHARACTERISTICS
UW
SUPPLY VOLTAGE (±V)
0
SLEW RATE (V/µs)
600
400
200
2000
1800
1600
1400
1200
1000
800
015105
1361/1362 G22
T
A
= 25°C
A
V
= –1
R
F
= R
G
= 1k
SR = SR
+
+ SR
–
—————
2
Slew Rate vs Input Level
Slew Rate vs Temperature
TEMPERATURE (°C)
200
SLEW RATE (V/µs)
400
300
1000
900
800
500
600
700
–50 –25 25 100 12550 750
1361/1362 G23
SR
+
+ SR
–
SR = —————
2
V
S
= ±5V
V
S
= ±15V
A
V
= –2
Total Harmonic Distortion
vs Frequency
FREQUENCY (Hz)
10
0.0001
TOTAL HARMONIC DISTORTION (%)
0.01
100 100k
1361/1362 G25
1k
0.001
10k
A
V
= –1
A
V
= 1
T
A
= 25°C
V
O
= 3V
RMS
R
L
= 500Ω
FREQUENCY (Hz)
100k 1M
0
OUTPUT VOLTAGE (VP-P)
30
10M
1361/1362 G26
15
5
10
25
20
AV = –1
AV = 1
VS = ±15V
RL = 1k
AV = 1, 1% MAX DISTORTION
AV = –1, 2% MAX DISTORTION
Undistorted Output Swing vs
Frequency (±15V) Undistorted Output Swing vs
Frequency (±5V)
FREQUENCY (Hz)
100k 1M
0
OUTPUT VOLTAGE (V
P-P
)
10
10M
1361/1362 G27
6
2
4
8A
V
= –1
A
V
= 1
V
S
= ±5V
R
L
= 1k
2% MAX DISTORTION
Slew Rate vs Supply Voltage
2nd and 3rd Harmonic Distortion
vs Frequency
FREQUENCY (Hz)
100k 200k 400k
–90
–80
–70
–60
–50
–40
HARMONIC DISTORTION (dB)
–30
10M
1361/1362 G28
1M 2M 4M
VS = ±15V
VO = 2VP-P
RL = 500Ω
AV = 2 3RD HARMONIC
2ND HARMONIC
CAPACITIVE LOAD (F)
10p
0
OVERSHOOT (%)
100
1µ
1361/1362 G30
1000p 0.01µ
50
100p 0.1µ
A
V
= 1
A
V
= –1
T
A
= 25°C
V
S
= ±15V
Capacitive Load Handling
INPUT LEVEL (V
P-P
)
0
SLEW RATE (V/µs)
400
600
200
2000
1800
1600
1400
800
1200
1000
0 8 16 2012421018146
1361/1362 G24
T
A
= 25°C
V
S
= ±15V
A
V
= –1
R
F
= R
G
= 1k
SR = SR
+
+ SR
–
—————
2
Differential Gain and Phase
vs Supply Voltage
SUPPLY VOLTAGE (V)
0.28
DIFFERENTIAL PHASE (DEG)
0.36
0.32
0.40
DIFFERENTIAL GAIN (%)
0.50
0.25
0
±10±5±15
1361/1362 G29
DIFFERENTIAL GAIN
DIFFERENTIAL PHASE
AV = 2
RL = 150Ω
TA = 25°C
L7LJCHWW
9
LT1361/LT1362
Small-Signal Transient
(AV = 1)
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Small-Signal Transient
(AV = –1) Small-Signal Transient
(AV = –1, CL = 500pF)
1361/1362 TA31 1361/1362 TA32 1361/1362 TA33
Large-Signal Transient
(AV = 1, CL = 10,000pF)
Large-Signal Transient
(AV = –1)
Large-Signal Transient
(AV = 1)
1361/1362 TA36
1361/1362 TA34 1361/1362 TA35
APPLICATIONS INFORMATION
WUUU
Layout and Passive Components
The LT1361/LT1362 amplifiers are easy to use and toler-
ant of less than ideal layouts. For maximum performance
(for example, fast 0.01% settling) 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). The
parallel combination of the feedback resistor and gain
setting resistor on the inverting input combine with the
input capacitance to form a pole which can cause peaking
or oscillations. If feedback resistors greater than 5kΩ are
used, a parallel capacitor of value
C
F
> R
G
x C
IN
/R
F
should be used to cancel the input pole and optimize
dynamic performance. For unity-gain applications where
a large feedback resistor is used, C
F
should be greater
than or equal to C
IN
.
Input Considerations
Each of the LT1361/LT1362 inputs is the base of an NPN
and a PNP transistor whose base currents are of opposite
polarity and provide first-order bias current cancellation.
Because of variation in the matching of NPN and PNP beta,
the polarity of the input bias current can be positive or
negative. The offset current does not depend on NPN/PNP
beta matching and is well controlled. The use of balanced
source resistance at each input is recommended for
applications where DC accuracy must be maximized.
The inputs can withstand transient differential input volt-
ages up to 10V without damage and need no clamping or
source resistance for protection. Differential inputs, how-
ever, generate large supply currents (tens of mA) as
required for high slew rates. If the device is used with
sustained differential inputs, the average supply current
will increase, excessive power dissipation will result and
the part may be damaged. The part should not be used as
a comparator, peak detector or other open-loop applica-
10
LT1361/LT1362
tion with large, sustained differential inputs. Under
normal, closed-loop operation, an increase of power dis-
sipation is only noticeable in applications with large slewing
outputs and is proportional to the magnitude of the
differential input voltage and the percent of the time that
the inputs are apart. Measure the average supply current
for the application in order to calculate the power dissipa-
tion.
Capacitive Loading
The LT1361/LT1362 are stable with any capacitive load.
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 so there will be peaking in the
frequency domain and in the transient response as shown
in the typical performance curves. The photo of the small
signal response with 500pF load shows 60% peaking. The
large signal response shows the output slew rate being
limited to 5V/µs by the short-circuit current. Coaxial cable
can be driven 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.
Circuit Operation
The LT1361/LT1362 circuit topology is a true voltage
feedback amplifier that has the slewing behavior of a
current feedback amplifier. The operation of the circuit can
be understood by referring to the simplified schematic.
The inputs are buffered by complementary NPN and PNP
emitter followers which drive a 500Ω resistor. The input
voltage appears across the resistor generating currents
which are mirrored into the high impedance node. Comple-
mentary followers form an output stage which buffers the
gain node from the load. The bandwidth is set by the input
resistor and the capacitance on the high impedance node.
The slew rate is determined by the current available to
charge the gain node capacitance. This current is the
differential input voltage divided by R1, so the slew rate is
proportional to the input. Highest slew rates are therefore
seen in the lowest gain configurations. For example, a 10V
output step in a gain of 10 has only a 1V input step,
APPLICATIONS INFORMATION
WUUU
whereas the same output step in unity gain has a 10 times
greater input step. The curve of Slew Rate vs Input Level
illustrates this relationship. The LT1361/LT1362 are tested
for slew rate in a gain of –2 so higher slew rates can be
expected in gains of 1 and –1, and lower slew rates in
higher gain configurations.
The RC network across the output stage is bootstrapped
when the amplifier is driving a light or moderate load and
has no effect under normal operation. When driving a
capacitive load (or a low value resistive load) the network
is incompletely bootstrapped and adds to the compensa-
tion at the high impedance node. The added capacitance
slows down the amplifier which improves the phase
margin by moving the unity-gain frequency away from the
pole formed by the output impedance and the capacitive
load. The zero created by the RC combination adds phase
to ensure that even for very large load capacitances, the
total phase lag can never exceed 180 degrees (zero phase
margin) and the amplifier remains stable.
Power Dissipation
The LT1361/LT1362 combine high speed and large output
drive in small packages. Because of the wide supply
voltage range, it is possible to exceed the maximum
junction temperature under certain conditions. Maximum
junction temperature (T
J
) is calculated from the ambient
temperature (T
A
) and power dissipation (P
D
) as follows:
LT1361CN8: T
J
= T
A
+ (P
D
x 130°C/W)
LT1361CS8: T
J
= T
A
+ (P
D
x 190°C/W)
LT1362CN: T
J
= T
A
+ (P
D
x 110°C/W)
LT1362CS: T
J
= T
A
+ (P
D
x 150°C/W)
Worst case power dissipation occurs at the maximum
supply current and when the output voltage is at 1/2 of
either supply voltage (or the maximum swing if less than
1/2 supply voltage). For each amplifier P
DMAX
is:
P
DMAX
= (V
+
– V
–
)(I
SMAX
) + (V
+
/2)
2
/R
L
Example: LT1362 in S16 at 70°C, V
S
= ±5V, R
L
= 100Ω
P
DMAX
= (10V)(5.6mA) + (2.5V)
2
/100Ω = 119mW
T
JMAX
= 70°C + (4 x 119mW)(150°C/W) = 141°C
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11
LT1361/LT1362
1361/1362 SS01
OUT
+IN
–IN
V
+
V
–
R1
500ΩC
C
R
C
C
SCHE ATIC
WW
SI PLIFIED
Dimension in inches (millimeters) unless otherwise noted.
PACKAGE DESCRIPTION
U
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 represen-
tation that the interconnection of its circuits as described herein will not infringe on existing patent rights.
N8 1098
0.100
(2.54)
BSC
0.065
(1.651)
TYP
0.045 – 0.065
(1.143 – 1.651)
0.130 ± 0.005
(3.302 ± 0.127)
0.020
(0.508)
MIN
0.018 ± 0.003
(0.457 ± 0.076)
0.125
(3.175)
MIN
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
12 34
8765
0.255 ± 0.015*
(6.477 ± 0.381)
0.400*
(10.160)
MAX
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
N14 1098
0.020
(0.508)
MIN
0.125
(3.175)
MIN
0.130 ± 0.005
(3.302 ± 0.127)
0.045 – 0.065
(1.143 – 1.651)
0.065
(1.651)
TYP
0.018 ± 0.003
(0.457 ± 0.076)
0.100
(2.54)
BSC
0.005
(0.125)
MIN
0.009 – 0.015
(0.229 – 0.381)
0.300 – 0.325
(7.620 – 8.255)
0.325 +0.035
–0.015
+0.889
–0.381
8.255
()
0.255 ± 0.015*
(6.477 ± 0.381)
0.770*
(19.558)
MAX
31 24567
8910
11
1213
14
*THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm)
N8 Package
8-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
N Package
14-Lead PDIP (Narrow 0.300)
(LTC DWG # 05-08-1510)
—l— T ”W , H H H H {521$ T I:l|:l|:lil I Hpi T 74PM 1 ,7H H H H A“? T'HHHHHHHH LJ—|\ H L j 7 T 1H7 ”iHHH 7 l LH H H H H H H H L7LJHHEGB
12
LT1361/LT1362
13612fa LT/TP 0400 2K REV A • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 1994
Dimension in inches (millimeters) unless otherwise noted.
PACKAGE DESCRIPTION
U
TYPICAL APPLICATIONS
U
Two Op Amp Instrumentation Amplifier 1MHz, 4th Order Butterworth Filter
1361/1362 TA03
VIN
TRIM R5 FOR GAIN
TRIM R1 FOR COMMON-MODE REJECTION
BW = 500kHz
R1
10k R2
1k
R5
220ΩR4
10k
R3
1k
VOUT
+
–
–
+
–
+1/2
LT1361
1/2
LT1361
GAIN R
R
R
R
R
R
RR
R
=
+
+
++
()
=
4
311
2
2
1
3
4
23
5102
1361/1362 TA04
VIN
1.1k
2.21k
22pF
909Ω
47pF
470pF VOUT
–
+
–
+
1.1k
2.67k909Ω
220pF 1/2
LT1361
1/2
LT1361
S8 Package
8-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
S Package
16-Lead Plastic Small Outline (Narrow 0.150)
(LTC DWG # 05-08-1610)
PART NUMBER DESCRIPTION COMMENTS
LT1360 50MHz, 800V/µs Op Amp Single Version of LT1361/LT1362
LT1364/LT1365 Dual and Quad 70MHz, 1000V/µs Op Amps Faster Version of LT1361/LT1362, V
OS
= 1.5mV, I
S
= 6.3mA/Amplifier
LT1358/LT1359 Dual and Quad 25MHz, 600Vµs Op Amps Lower Power Version of LT1361/LT1362, V
OS
= 0.6mV, I
S
= 2mA/Amplifier
LT1813 Dual 100MHz, 700V/µs Op Amps Low Voltage, Low Power LT1361, I
S
= 3mA/Amplifier
RELATED PARTS
0.016 – 0.050
(0.406 – 1.270)
0.010 – 0.020
(0.254 – 0.508)× 45°
0° – 8° TYP
0.008 – 0.010
(0.203 – 0.254)
S16 1098
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
12345678
0.150 – 0.157**
(3.810 – 3.988)
16 15 14 13
0.386 – 0.394*
(9.804 – 10.008)
12 11 10 9
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
*
**
0.228 – 0.244
(5.791 – 6.197)
0.016 – 0.050
(0.406 – 1.270)
0.010 – 0.020
(0.254 – 0.508)× 45°
0°– 8° TYP
0.008 – 0.010
(0.203 – 0.254)
SO8 1298
0.053 – 0.069
(1.346 – 1.752)
0.014 – 0.019
(0.355 – 0.483)
TYP
0.004 – 0.010
(0.101 – 0.254)
0.050
(1.270)
BSC
1234
0.150 – 0.157**
(3.810 – 3.988)
8765
0.189 – 0.197*
(4.801 – 5.004)
0.228 – 0.244
(5.791 – 6.197)
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
*
**
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900
●
FAX: (408) 434-0507
●
www.linear-tech.com