LT1818/LT1819
400MHz, 2500V/µs, 9mA
Single/Dual Operational
Amplifiers
DESCRIPTION
FEATURES
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400MHz Gain Bandwidth Product
2500V/μs Slew Rate
–85dBc Distortion at 5MHz
9mA Supply Current Per Amplifier
6nV/√Hz Input Noise Voltage
Unity-Gain Stable
1.5mV Maximum Input Offset Voltage
8μA Maximum Input Bias Current
800nA Maximum Input Offset Current
40mA Minimum Output Current, VOUT = ±3V
±3.5V Minimum Input CMR, VS = ±5V
Specified at ±5V, Single 5V Supplies
Operating Temperature Range: –40°C to 85°C
Low Profile (1mm) TSOT-23 (ThinSOT™) Package
The LT®1818/LT1819 are single/dual wide bandwidth, high
slew rate, low noise and distortion operational amplifiers
with excellent DC performance. The LT1818/LT1819 have
been designed for wider bandwidth and slew rate, much
lower input offset voltage and lower noise and distortion
than devices with comparable supply current. The circuit
topology is a voltage feedback amplifier with the excellent
slewing characteristics of a current feedback amplifier.
The output drives a 100Ω load to ±3.8V with ±5V supplies. On a single 5V supply, the output swings from 1V
to 4V with a 100Ω load connected to 2.5V. The amplifier
is unity-gain stable with a 20pF capacitive load without the
need for a series resistor. Harmonic distortion is –85dBc
up to 5MHz for a 2VP-P output at a gain of 2.
APPLICATIONS
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The LT1818/LT1819 are manufactured on Linear Technology’s advanced low voltage complementary bipolar
process. The LT1818 (single op amp) is available in
TSOT-23 and SO-8 packages; the LT1819 (dual op amp)
is available in MSOP-8 and SO-8 packages.
Wideband Amplifiers
Buffers
Active Filters
Video and RF Amplification
Communication Receivers
Cable Drivers
Data Acquisition Systems
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear
Technology Corporation. ThinSOT is a trademark of Linear Technology Corporation.
All other trademarks are the property of their respective owners.
TYPICAL APPLICATION
FFT of Single Supply ADC Driver
0
Single Supply Unity-Gain ADC Driver for Oversampling Applications
fIN = 5.102539MHz
fS = 50Msps
VIN = 300mVP-P
SFDR = 78dB
8192 POINT FFT
NO WINDOWING
OR AVERAGING
–10
–20
2.5VDC
±1VAC
+
51.1Ω
AIN+
LT1818
–
18pF
2.5V
AIN–
LTC1744
14 BITS
50Msps
(SET FOR 2VP-P
FULL SCALE)
AMPLITUDE (dBc)
5V
5V
–30
–40
–50
–60
–70
2
–80
3
–90
18189 TA01
–100
–110
0
5M
10M
15M
20M
FREQUENCY (Hz)
25M
18189 TA02
18189fb
1
LT1818/LT1819
ABSOLUTE MAXIMUM RATINGS (Note 1)
Total Supply Voltage (V+ to V–) ..............................12.6V
Differential Input Voltage (Transient Only, Note 2).....±6V
Output Short-Circuit Duration (Note 3) ............ Indefinite
Operating Temperature Range (Note 8).... –40°C to 85°C
Specified Temperature Range (Note 9) .... –40°C to 85°C
Maximum Junction Temperature........................... 150°C
Storage Temperature Range................... –65°C to 150°C
Lead Temperature (Soldering, 10 sec) .................. 300°C
PIN CONFIGURATION
TOP VIEW
TOP VIEW
OUT 1 1
OUT A
–IN A
+IN A
V–
5 V+
V– 2
+
+IN 3
–
4 –IN
1
2
3
4
TJMAX = 150°C, θJA = 250°C/W (NOTE 10)
TJMAX = 150°C, θJA = 250°C/W (NOTE 10)
TOP VIEW
–IN 2
+IN 3
V–
–
+
4
B
V+
OUT B
–IN B
+IN B
MS8 PACKAGE
8-LEAD PLASTIC MSOP
S5 PACKAGE
5-LEAD PLASTIC TSOT-23
NC 1
A
8
7
6
5
TOP VIEW
8
NC
OUT A 1
7
V+
–IN A 2
6
OUT
+IN A 3
NC
V–
8
V+
7
OUT B
6
–IN B
5
+IN B
A
5
B
4
S8 PACKAGE
8-LEAD PLASTIC SO
S8 PACKAGE
8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 150°C/W (NOTE 10)
TJMAX = 150°C, θJA = 150°C/W (NOTE 10)
ORDER INFORMATION
LEAD FREE FINISH
TAPE AND REEL
PART MARKING*
PACKAGE DESCRIPTION
SPECIFIED TEMPERATURE RANGE
LT1818CS5#PBF
LT1818CS5#TRPBF
LTF7
5-Lead Plastic TSOT-23
0°C to 70°C
LT1818IS5#PBF
LT1818IS5#TRPBF
LTF7
5-Lead Plastic TSOT-23
–40°C to 85°C
LT1818CS8#PBF
LT1818CS8#TRPBF
1818
8-Lead Plastic SO
0°C to 70°C
LT1818IS8#PBF
LT1818IS8#TRPBF
1818I
8-Lead Plastic SO
–40°C to 85°C
LT1819CMS8#PBF
LT1819CMS8#TRPBF
LTE7
8-Lead Plastic MSOP
0°C to 70°C
LT1819IMS8#PBF
LT1819IMS8#TRPBF
LTE5
8-Lead Plastic MSOP
–40°C to 85°C
LT1819CS8#PBF
LT1819CS8#TRPBF
1819
8-Lead Plastic SO
0°C to 70°C
LT1819IS8#PBF
LT1819IS8#TRPBF
1819I
8-Lead Plastic SO
–40°C to 85°C
Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.
Consult LTC Marketing for information on non-standard lead based finish parts.
For more information on lead free part marking, go to: http://www.linear.com/leadfree/
For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/
18189fb
2
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 9) VS = ±5V, VCM = 0V, unless otherwise noted.
SYMBOL
VOS
PARAMETER
Input Offset Voltage
ΔVOS/ΔT
Input Offset Voltage Drift
IOS
Input Offset Current
IB
Input Noise Voltage Density
Input Noise Current Density
Input Resistance
CIN
VCM
Input Capacitance
Input Voltage Range
(Positive/Negative)
Common Mode Rejection Ratio
Minimum Supply Voltage
PSRR
Power Supply Rejection Ratio
AVOL
Large-Signal Voltage Gain
Channel Separation
VOUT
Output Swing (Positive/Negative)
IOUT
Output Current
ISC
Output Short-Circuit Current
SR
Slew Rate
FPBW
l
l
TA = 0°C to 70°C
TA = –40°C to 85°C
l
l
TA = 0°C to 70°C
TA = –40°C to 85°C
f = 10kHz
f = 10kHz
VCM = V– + 1.5V to V+ – 1.5V
Differential
l
l
Input Bias Current
en
in
RIN
CMRR
CONDITIONS
(Note 4)
TA = 0°C to 70°C
TA = –40°C to 85°C
TA = 0°C to 70°C (Note 7)
TA = –40°C to 85°C (Note 7)
Full-Power Bandwidth
Guaranteed by CMRR
TA = –40°C to 85°C
VCM = ±3.5V
TA = 0°C to 70°C
TA = –40°C to 85°C
Guaranteed by PSRR
TA = –40°C to 85°C
VS = ±2V to ±5.5V
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = ±3V, RL = 500Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = ±3V, RL = 100Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = ±3V, LT1819
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 500Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 100Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = ±3V, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = 0V, 1V Overdrive (Note 3)
TA = 0°C to 70°C
TA = –40°C to 85°C
AV = 1
AV = –1 (Note 5)
TA = 0°C to 70°C
TA = –40°C to 85°C
6VP-P (Note 6)
MIN
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10
10
60
–2
1.5
l
l
l
±3.5
±3.5
75
73
72
l
l
78
76
75
1.5
1.0
0.6
1.0
0.7
0.6
82
81
80
±3.8
±3.7
±3.6
±3.50
±3.25
±3.15
±40
±35
±30
±100
±90
±70
l
l
900
750
600
l
l
l
l
l
l
l
l
l
l
l
l
MAX
1.5
2.0
3.0
15
30
800
1000
1200
±8
±10
±12
6
1.2
5
750
1.5
±4.2
85
±1.25
l
l
l
TYP
0.2
97
2.5
6
100
±4.1
±3.8
±70
±200
2500
1800
95
±2
±2
UNITS
mV
mV
mV
μV/°C
μV/°C
nA
nA
nA
μA
μA
μA
nV/√Hz
pA/√Hz
MΩ
kΩ
pF
V
V
dB
dB
dB
V
V
dB
dB
dB
V/mV
V/mV
V/mV
V/mV
V/mV
V/mV
dB
dB
dB
V
V
V
V
V
V
mA
mA
mA
mA
mA
mA
V/μs
V/μs
V/μs
V/μs
MHz
18189fb
3
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 9) VS = ±5V, VCM = 0V, unless otherwise noted.
SYMBOL
GBW
PARAMETER
Gain-Bandwidth Product
tr , tf
tPD
OS
tS
HD
Rise Time, Fall Time
Propagation Delay
Overshoot
Settling Time
Harmonic Distortion
dG
dP
IS
Differential Gain
Differential Phase
Supply Current
CONDITIONS
f = 4MHz, RL = 500Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
AV = 1, 10% to 90%, 0.1V Step
AV = 1, 50% to 50%, 0.1V Step
AV = 1, 0.1V, RL = 100Ω
AV = –1, 0.1%, 5V
HD2, AV = 2, f = 5MHz, VOUT = 2VP-P , RL = 500Ω
HD3, AV = 2, f = 5MHz, VOUT = 2VP-P , RL = 500Ω
AV = 2, RL = 150Ω
AV = 2, RL = 150Ω
Per Amplifier
TA = 0°C to 70°C
TA = –40°C to 85°C
l
l
MIN
270
260
250
TYP
400
0.6
1.0
20
10
–85
–89
0.07
0.02
9
l
l
MAX
10
13
14
UNITS
MHz
MHz
MHz
ns
ns
%
ns
dBc
dBc
%
DEG
mA
mA
mA
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C.
(Note 9) VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted.
SYMBOL
VOS
PARAMETER
Input Offset Voltage
ΔVOS/ΔT
Input Offset Voltage Drift
IOS
Input Offset Current
IB
Input Noise Voltage Density
Input Noise Current Density
Input Resistance
CIN
VCM
Input Capacitance
Input Voltage Range (Positive)
Input Voltage Range (Negative)
Common Mode Rejection Ratio
Minimum Supply Voltage
PSRR
Power Supply Rejection Ratio
MIN
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l
l
TA = 0°C to 70°C
TA = –40°C to 85°C
l
l
TA = 0°C to 70°C
TA = –40°C to 85°C
f = 10kHz
f = 10kHz
VCM = V– + 1.5V to V+ – 1.5V
Differential
l
l
Input Bias Current
en
in
RIN
CMRR
CONDITIONS
(Note 4)
TA = 0°C to 70°C
TA = –40°C to 85°C
(Note 7)
TA = 0°C to 70°C
TA = –40°C to 85°C
Guaranteed by CMRR
TA = –40°C to 85°C
Guaranteed by CMRR
TA = –40°C to 85°C
VCM = 1.5V to 3.5V
TA = 0°C to 70°C
TA = –40°C to 85°C
Guaranteed by PSRR
TA = –40°C to 85°C
VS = 4V to 11V
TA = 0°C to 70°C
TA = –40°C to 85°C
3.5
3.5
73
71
70
10
10
60
15
30
800
1000
1200
±8
±10
±12
μV/°C
μV/°C
nA
nA
nA
μA
μA
μA
nV/√Hz
pA/√Hz
MΩ
kΩ
pF
V
V
V
V
dB
dB
dB
V
V
dB
dB
dB
6
1.4
5
750
1.5
4.2
78
76
75
1.5
1.5
82
±1.25
l
l
l
UNITS
mV
mV
mV
0.8
l
l
l
MAX
2.0
2.5
3.5
–2.4
1.5
l
TYP
0.4
97
±2
±2
18189fb
4
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at TA = 25°C. (Note 9) VS = 5V, 0V; VCM = 2.5V, RL to 2.5V unless otherwise noted.
SYMBOL
AVOL
PARAMETER
Large-Signal Voltage Gain
Channel Separation
VOUT
Output Swing (Positive)
Output Swing (Negative)
IOUT
Output Current
ISC
Output Short-Circuit Current
SR
Slew Rate
FPBW
GBW
Full-Power Bandwidth
Gain-Bandwidth Product
tr , tf
tPD
OS
HD
Rise Time, Fall Time
Propagation Delay
Overshoot
Harmonic Distortion
dG
dP
IS
Differential Gain
Differential Phase
Supply Current
CONDITIONS
VOUT = 1.5V to 3.5V, RL = 500Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = 1.5V to 3.5V, RL = 100Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = 1.5V to 3.5V, LT1819
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 500Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 100Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 500Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
RL = 100Ω, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = 1.5V or 3.5V, 30mV Overdrive
TA = 0°C to 70°C
TA = –40°C to 85°C
VOUT = 2.5V, 1V Overdrive (Note 3)
TA = 0°C to 70°C
TA = –40°C to 85°C
AV = 1
AV = –1 (Note 5)
TA = 0°C to 70°C
TA = –40°C to 85°C
2VP-P (Note 6)
f = 4MHz, RL = 500Ω
TA = 0°C to 70°C
TA = –40°C to 85°C
AV = 1, 10% to 90%, 0.1V Step
AV = 1, 50% to 50%, 0.1V Step
AV = 1, 0.1V, RL = 100Ω
HD2, AV = 2, f = 5MHz, VOUT = 2VP-P , RL = 500Ω
HD3, AV = 2, f = 5MHz, VOUT = 2VP-P , RL = 500Ω
AV = 2, RL = 150Ω
AV = 2, RL = 150Ω
Per Amplifier
TA = 0°C to 70°C
TA = –40°C to 85°C
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: Differential inputs of ±6V are appropriate for transient operation
only, such as during slewing. Large sustained differential inputs can cause
excessive power dissipation and may damage the part.
l
l
l
l
l
l
l
l
l
l
MIN
1.0
0.7
0.6
0.7
0.5
0.4
81
80
79
3.9
3.8
3.7
3.7
3.6
3.5
±30
±25
±20
±80
±70
±50
l
l
450
375
300
l
l
240
230
220
l
l
100
4.2
4
1
l
l
MAX
4
0.8
l
l
l
l
TYP
2
1.1
1.2
1.3
1.3
1.4
1.5
±50
±140
1000
800
125
360
0.7
1.1
20
–72
–74
0.07
0.07
8.5
10
13
14
UNITS
V/mV
V/mV
V/mV
V/mV
V/mV
V/mV
dB
dB
dB
V
V
V
V
V
V
V
V
V
V
V
V
mA
mA
mA
mA
mA
mA
V/μs
V/μs
V/μs
V/μs
MHz
MHz
MHz
MHz
ns
ns
%
dBc
dBc
%
DEG
mA
mA
mA
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.
18189fb
5
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
Note 5: With ±5V supplies, slew rate is tested in a closed-loop gain of –1
by measuring the rise time of the output from –2V to 2V with an output
step from –3V to 3V. With single 5V supplies, slew rate is tested in a
closed-loop gain of –1 by measuring the rise time of the output from 1.5V
to 3.5V with an output step from 1V to 4V. Falling edge slew rate is not
production tested, but is designed, characterized and expected to be within
10% of the rising edge slew rate.
Note 8: The LT1818C/LT1818I and LT1819C/LT1819I are guaranteed
functional over the operating temperature range of –40°C to 85°C.
Note 6: Full-power bandwidth is calculated from the slew rate:
Note 10: Thermal resistance (θJA) varies with the amount of PC board
metal connected to the package. The specified values are for short
traces connected to the leads. If desired, the thermal resistance can be
significantly reduced by connecting the V– pin to a large metal area.
Note 9: The LT1818C/LT1819C are guaranteed to meet specified
performance from 0°C to 70°C and is designed, characterized and
expected to meet the extended temperature limits, but is not tested
at –40°C and 85°C. The LT1818I/LT1819I are guaranteed to meet the
extended temperature limits.
FPBW = SR/2πVP
Note 7: This parameter is not 100% tested.
TYPICAL PERFORMANCE CHARACTERISTICS
Input Common Mode Range
vs Supply Current
Supply Current vs Temperature
SUPPLY CURRENT (mA)
10
VS = ±5V
8
VS = ±2.5V
6
4
2
V+
2
–1.0
0
TA = 25°C
–0.5 $VOS < 1mV
INPUT BIAS CURRENT (μA)
PER AMPLIFIER
INPUT COMMON MODE RANGE (V)
12
Input Bias Current vs Common
Mode Voltage
–1.5
–2.0
2.0
1.5
1.0
TA = 25°C
VS = ±5V
–2
–4
–6
0.5
–25
50
25
0
75
TEMPERATURE (°C)
100
V–
125
–8
0
1
4
3
2
5
SUPPLY VOLTAGE (±V)
18189 G01
VCM = 0V
INPUT VOLTAGE NOISE (nV/√Hz)
INPUT BIAS CURRENT (μA)
–1.2
–1.6
–2.0
–2.4
Open-Loop Gain vs Resistive Load
10
VS = ±5V
VS = ±2.5V
TA = 25°C
VS = ±5V
AV = 101
RS = 10k
in
1
10
en
80
INPUT CURRENT NOISE (pA/√Hz)
–0.8
5
18189 G03
Input Noise Spectral Density
100
–0.4
0
2.5
–2.5
INPUT COMMON MODE VOLTAGE (V)
–5
18189 G02
Input Bias Current vs Temperature
0
7
6
TA = 25°C
77
OPEN-LOOP GAIN (dB)
0
–50
74
71
68
VS = ±5V
65
VS = ±2.5V
–2.8
–50 –25
50
25
75
0
TEMPERATURE (°C)
100
125
18189 G04
1
10
100
1k
10k
FREQUENCY (Hz)
0.1
100k
18189 G05
62
100
1k
LOAD RESISTANCE (Ω)
10k
18189 G06
18189fb
6
LT1818/LT1819
TYPICAL PERFORMANCE CHARACTERISTICS
Output Voltage Swing
vs Supply Voltage
Open-Loop Gain vs Temperature
71
RL = 500Ω
65
RL = 500Ω
–1.0
RL = 100Ω
–1.5
–2.0
2.0
1.5
RL = 100Ω
1.0
50
25
75
0
TEMPERATURE (°C)
100
V–
125
0
4
3
2
5
SUPPLY VOLTAGE (±V)
1
18189 G07
3
SINK
–3
2
–4
–5
–120
7
6
–80
0
40
80
–40
OUTPUT CURRENT (mA)
120
18189 G09
Output Current vs Temperature
Output Impedance vs Frequency
100
SOURCE
200
125
SINK
160
120
80
40
SOURCE, VS = ±5V
100
SINK, VS = ±5V
SINK, VS = ±2.5V
50
100
50
25
75
0
TEMPERATURE (°C)
18189 G10
180
70
160
60
140
125
PHASE (DEG)
100
40
30
80
20
60
10
40
TA = 25°C
VS = ±5V
100k
1M
10M
FREQUENCY (Hz)
RL = 500Ω
400
Gain vs Frequency, A V = 1
5
GBW
VS = ±5V
GBW
VS = ±2.5V
360
PHASE MARGIN
VS = ±2.5V
100M
18189 G12
50
PHASE MARGIN
VS = ±5V
20
PHASE MARGIN (DEG)
120
GAIN
440
GAIN BANDWIDTH (MHz)
80
0
TA = 25°C
–10 AV = –1
RL = 500Ω
–20
10k
100k
100
0.01
10k
Gain Bandwidth and Phase
Margin vs Temperature
50
AV = 1
0.1
18189 G11
Gain and Phase vs Frequency
PHASE
AV = 10
1
$VOS = 30mV
VOUT = ±3V FOR VS = ±5V
VOUT = ±1V FOR VS = ±2.5V
0
–50 –25
125
AV = 100
10
TA = 25°C
AV = 1
RL = 500Ω
VS = ±5V
VS = ±2.5V
0
GAIN (dB)
50
25
75
0
TEMPERATURE (°C)
SOURCE, VS = ±2.5V
75
25
0
–50 –25
GAIN (dB)
SOURCE
–2
150
OUTUPT CURRENT (mA)
OUTPUT SHORT-CIRCUIT CURRENT (mA)
VS = ±5V
VIN = ±1V
4
18189 G08
Output Short-Circuit Current
vs Temperature
240
TA = 25°C
VS = ±5V
$VOS = 30mV
RL = 500Ω
0.5
62
–50 –25
OUTPUT VOLTAGE SWING (V)
RL = 100Ω
74
68
5
TA = 25°C
–0.5 $VOS = 30mV
OUTPUT IMPEDANCE (Ω)
OPEN-LOOP GAIN (dB)
V+
OUTPUT VOLTAGE SWING (V)
77
VS = ±5V
VO = ±3V
OUTPUT VOLTAGE SWING (V)
80
Output Voltage Swing
vs Load Current
–5
40
0
1M
10M
FREQUENCY (Hz)
100M
–20
500M
18189 G13
–50
–25
50
25
0
75
TEMPERATURE (°C)
100
30
125
18189 G15
–10
1M
10M
100M
FREQUENCY (Hz)
500M
18189 G16
18189fb
7
LT1818/LT1819
TYPICAL PERFORMANCE CHARACTERISTICS
Gain vs Frequency, A V = 2
10
Gain-Bandwidth and Phase
Margin vs Supply Voltage
Gain vs Frequency, A V = –1
5
RL = 500Ω
450
VS = ±5V
TA = 25°C
400
GBW
RL = 500Ω
0
GAIN (dB)
0
TA = 25°C
–5 A = 2
V
VS = ±5V
RF = RG = 500Ω
CF = 1pF
–10
1M
10M
FREQUENCY (Hz)
–5
100M
100
40
PHASE MARGIN
RL = 500Ω
10M
FREQUENCY (Hz)
100M
100
+PSRR
60
40
20
Slew Rate vs Input Step
TA =25°C
AV = –1
V = ±5V
1600 RS = R = R = 500Ω
F
G
L
TA = 25°C
VS = ±2.5V
1M
100k
FREQUENCY (Hz)
10M
VS = ±5V
60
40
800
400
0
1k
10k
100k
1M
FREQUENCY (Hz)
10M
18189 G20
2400
VIN = 6VP-P
VS = ±5V
SLEW RATE (V/μs)
1600
1200
VS = ±2.5V
800
500
400
0
1
4
3
2
5
SUPPLY VOLTAGE (±V)
6
7
18189 G23
6
AV = –1
RF = RG = RL = 500Ω
0
–50 –25
50
25
75
0
TEMPERATURE (°C)
0.06
0.04
0.10
0.02
0.08
0
0.06
DIFFERENTIAL PHASE
RL = 150Ω
0.04
0
125
18189 G24
0.08
0.12
0.02
100
0.10
DIFFERENTIAL GAIN
RL = 150Ω
DIFFERENTIAL GAIN (%)
VIN = 2VP-P
4
5
INPUT STEP (VP-P)
TA = 25°C
2000
1000
3
Differential Gain and Phase
vs Supply Voltage
Slew Rate vs Temperature
1500
0
2
18189 G22
DIFFERENTIAL PHASE (DEG)
TA =25°C
AV = –1
RF = RG = RL = 500Ω
100M
18189 G21
Slew Rate vs Supply Voltage
2000
SR–
SR+
1200
20
100M
6
2000
0
10k
35
18189 G19
80
0
1k
5
4
3
SUPPLY VOLTAGE (±V)
2
300M
Common Mode Rejection Ratio
vs Frequency
TA = 25°C
AV = 1
VS = ±5V
80
45
18189 G18
COMMON MODE REJECTION RATIO (dB)
POWER SUPPLY REJECTION RATIO (dB)
PHASE MARGIN
RL = 100Ω
30
–10
1M
300M
Power Supply Rejection Ratio
vs Frequency
SLEW RATE (V/μs)
GBW
RL = 100Ω
300
TA = 25°C
AV = –1
RL = RF = RG = 500Ω
18189 G17
PSRR
350
SLEW RATE (V/μs)
GAIN (dB)
RL = 100Ω
PHASE MARGIN (DEG)
GAIN BANDWIDTH (MHz)
VS = ±2.5V
5
2
4
3
5
SUPPLY VOLTAGE (±V)
6
18189 G25
18189fb
8
LT1818/LT1819
TYPICAL PERFORMANCE CHARACTERISTICS
Distortion vs Frequency, A V = 2
Distortion vs Frequency, A V = –1
–60
DISTORTION (dB)
DISTORTION (dB)
–80
–70
2ND, RL = 500Ω
–90
3RD, RL = 500Ω
–100
AV = 2
VS = ±5V
VO = 2VP-P
–120
1M
–80
10M
3RD, RL = 500Ω
–90
3RD, RL = 100Ω
–100
–110
2M
5M
FREQUENCY (Hz)
2ND, RL = 500Ω
–70
–80
3RD, RL = 100Ω
–120
1M
2ND, RL = 100Ω
–90
–100
3RD, RL = 500Ω
AV = –1
VS = ±5V
VO = 2VP-P
–110
2ND, RL = 500Ω
10M
2M
5M
FREQUENCY (Hz)
–120
1M
2M
5M
FREQUENCY (Hz)
18189 G27
18189 G26
Channel Separation vs Frequency
DISTORTION (dB)
3RD, RL = 100Ω
–70
AV = 1
VS = ±5V
VO = 2VP-P
2ND, RL = 100Ω
2ND, RL = 100Ω
–110
Distortion vs Frequency, A V = 1
–60
–60
10M
18189 G28
0.1% Settling Time
Small-Signal Transient, 20dB Gain
110
CHANNEL SEPARATION (dB)
100
INPUT
TRIGGER
(1V/DIV)
90
80
OUTPUT
SETTLING
RESIDUE
(5mV/DIV)
70
60
50
20mV/DIV
40
T = 25°C
30 VA = ±5V
S
20 AV = –1
RF = RG = RL = 500Ω
10
100k
1M
10M
10k
FREQUENCY (Hz)
100M
1G
5ns/DIV
VS = ±5V
VOUT = ±2.5V
SETTLING TIME = 9ns
AV = –1
RF = RG = 500Ω
CF = 4.1pF
18189 G30
10ns/DIV
18189 G31
18188 G29
Large-Signal Transient, A V = –1
Large-Signal Transient, A V = 1
1V/DIV
2V/DIV
VS = ±5V
5ns/DIV
18189 G32
Large-Signal Transient, A V = –1
1V/DIV
VS = ±5V
10ns/DIV
18189 G33
VS = ±5V
10ns/DIV
18189 G34
18189fb
9
LT1818/LT1819
APPLICATIONS INFORMATION
Layout and Passive Components
load, a resistor of 10Ω to 50Ω must be connected between
the output and the capacitive load to avoid ringing or
oscillation (see RS in Figure 1). The feedback must still be
taken directly from the output so that the series resistor
will isolate the capacitive load to ensure stability.
As with all high speed amplifiers, the LT1818/LT1819
require some attention to board layout. A ground plane
is recommended and trace lengths should be minimized,
especially on the negative input lead.
Input Considerations
Low ESL/ESR bypass capacitors should be placed directly
at the positive and negative supply (0.01μF ceramics are
recommended). For high drive current applications, additional 1μF to 10μF tantalums should be added.
The inputs of the LT1818/LT1819 amplifiers are connected
to the bases of NPN and PNP bipolar transistors in parallel. The base currents are of opposite polarity and provide
first order bias current cancellation. Due to variation in the
matching of NPN and PNP beta, the polarity of the input
bias current can be positive or negative. The offset current,
however, does not depend on beta matching and is tightly
controlled. Therefore, the use of balanced source resistance
at each input is recommended for applications where DC
accuracy must be maximized. For example, with a 100Ω
source resistance at each input, the 800nA maximum offset
current results in only 80μV of extra offset, while without
balance the 8μA maximum input bias current could result
in an 0.8mV offset condition.
The parallel combination of the feedback resistor and gain
setting resistor on the inverting input combine with the
input capacitance to form a pole that can cause peaking or
even oscillations. If feedback resistors greater than 500Ω
are used, a parallel capacitor of value
CF > RG • CIN/RF
should be used to cancel the input pole and optimize
dynamic performance (see Figure 1). For applications
where the DC noise gain is 1 and a large feedback resistor is used, CF should be greater than or equal to CIN. An
example would be an I-to-V converter.
The inputs can withstand differential input voltages of
up to 6V without damage and without needing clamping
or series resistance for protection. This differential input
voltage generates a large internal current (up to 50mA),
which results in the high slew rate. In normal transient
closed-loop operation, this does not increase power dissipation significantly because of the low duty cycle of the
transient inputs. Sustained differential inputs, however,
will result in excessive power dissipation and therefore
this device should not be used as a comparator.
In high closed-loop gain configurations, RF >> RG, no CF
needs to be added. To optimize the bandwidth in these
applications, a capacitor, CG, may be added in parallel with
RG in order to cancel out any parasitic CF capacitance.
Capacitive Loading
The LT1818/LT1819 are optimized for low distortion and
high gain bandwidth applications. The amplifiers can drive
a capacitive load of 20pF in a unity-gain configuration and
more with higher gain. When driving a larger capacitive
IN+
IN–
+
RG
CG
RS
CLOAD
–
RF
CF
18189 F01
Figure 1
18189fb
10
LT1818/LT1819
APPLICATIONS INFORMATION
Slew Rate
The slew rate of the LT1818/LT1819 is proportional to the
differential input voltage. Highest slew rates are therefore
seen in the lowest gain configurations. For example, a 6V
output step with a gain of 10 has a 0.6V input step, whereas
at unity gain there is a 6V input step. The LT1818/LT1819
is tested for slew rate at a gain of –1. Lower slew rates
occur in higher gain configurations, whereas the highest
slew rate (2500V/μs) occurs in a noninverting unity-gain
configuration.
Power Dissipation
The LT1818/LT1819 combine high speed and large output
drive in small packages. It is possible to exceed the maximum junction temperature specification (150°C) under
certain conditions. Maximum junction temperature (TJ)
is calculated from the ambient temperature (TA), power
dissipation per amplifier (PD) and number of amplifiers
(n) as follows:
TJ = TA + (n • PD • θJA)
Power dissipation is composed of two parts. The first is
due to the quiescent supply current and the second is
due to on-chip dissipation caused by the load current.
The worst-case load-induced power occurs when the
output voltage is at 1/2 of either supply voltage (or the
maximum swing if less than 1/2 the supply voltage).
Therefore PDMAX is:
Example: LT1819IS8 at 85°C, VS = ±5V, RL = 100Ω
PDMAX = (10V) • (14mA) + (2.5V)2/100Ω = 202.5mW
TJMAX = 85°C + (2 • 202.5mW) • (150°C/W) = 146°C
Circuit Operation
The LT1818/LT1819 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.
Complementary NPN and PNP emitter followers buffer
the inputs and drive an internal resistor. The input voltage
appears across the resistor, generating a current that is
mirrored into the high impedance node.
Complementary followers form an output stage that buffer the gain node from the load. The input resistor, input
stage transconductance and the capacitor on the high
impedance node determine the bandwidth. 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 step. Highest slew rates are therefore seen in
the lowest gain configurations.
PDMAX = (V+ – V–) • (ISMAX) + (V+/2)2/RL or
PDMAX = (V+ – V–) • (ISMAX) + (V+ – VOMAX) • (VOMAX/RL)
18189fb
11
LT1818/LT1819
TYPICAL APPLICATION
Single Supply Differential ADC Driver
5V
10μF
18pF
+
VIN
51.1Ω
1/2 LT1819
5V
–
AIN+
18pF
536Ω
AIN–
536Ω
–
LTC1744
14 BITS
50Msps
(SET FOR 2VP-P
FULL SCALE)
18189 TA05
51.1Ω
1/2 LT1819
4.99k
18pF
+
5V
4.99k
0.1μF
Results Obtained with the Circuit of Figure 2 at 5MHz.
FFT Shows 81dB Overall Spurious Free Dynamic Range
0
fIN = 5.023193MHz
fS = 50Msps
VIN = 750mVP-P
–10
–20
8192 SAMPLES
NO WINDOWING
NO AVERAGING
AMPLITUDE (dBc)
–30
–40
–50
–60
–70
–80
–90
–100
–110
–120
0
5M
10M
15M
20M
FREQUENCY (Hz)
25M
18189 TA06
18189fb
12
LT1818/LT1819
SIMPLIFIED SCHEMATIC
(One Amplifier)
V+
R1
+IN
OUT
–IN
C
V–
18189 SS
18189fb
13
LT1818/LT1819
PACKAGE DESCRIPTION
MS8 Package
8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660 Rev F)
0.889 p 0.127
(.035 p .005)
5.23
(.206)
MIN
3.20 – 3.45
(.126 – .136)
0.42 p 0.038
(.0165 p .0015)
TYP
3.00 p 0.102
(.118 p .004)
(NOTE 3)
0.65
(.0256)
BSC
8
7 6 5
0.52
(.0205)
REF
RECOMMENDED SOLDER PAD LAYOUT
0.254
(.010)
3.00 p 0.102
(.118 p .004)
(NOTE 4)
4.90 p 0.152
(.193 p .006)
DETAIL “A”
0o – 6o TYP
GAUGE PLANE
1
0.53 p 0.152
(.021 p .006)
DETAIL “A”
2 3
4
1.10
(.043)
MAX
0.86
(.034)
REF
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.65
(.0256)
BSC
0.1016 p 0.0508
(.004 p .002)
MSOP (MS8) 0307 REV F
NOTE:
1. DIMENSIONS IN MILLIMETER/(INCH)
2. DRAWING NOT TO SCALE
3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS.
MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS.
INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE
5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX
18189fb
14
LT1818/LT1819
PACKAGE DESCRIPTION
S5 Package
5-Lead Plastic TSOT-23
(Reference LTC DWG # 05-08-1635)
0.62
MAX
0.95
REF
2.90 BSC
(NOTE 4)
1.22 REF
1.4 MIN
3.85 MAX 2.62 REF
2.80 BSC
1.50 – 1.75
(NOTE 4)
PIN ONE
RECOMMENDED SOLDER PAD LAYOUT
PER IPC CALCULATOR
0.30 – 0.45 TYP
5 PLCS (NOTE 3)
0.95 BSC
0.80 – 0.90
0.20 BSC
0.01 – 0.10
1.00 MAX
DATUM ‘A’
0.30 – 0.50 REF
0.09 – 0.20
(NOTE 3)
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DRAWING NOT TO SCALE
3. DIMENSIONS ARE INCLUSIVE OF PLATING
4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
5. MOLD FLASH SHALL NOT EXCEED 0.254mm
6. JEDEC PACKAGE REFERENCE IS MO-193
1.90 BSC
S5 TSOT-23 0302 REV B
18189fb
15
LT1818/LT1819
PACKAGE DESCRIPTION
S8 Package
8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 p.005
.050 BSC
8
.245
MIN
7
6
5
.160 p.005
.150 – .157
(3.810 – 3.988)
NOTE 3
.228 – .244
(5.791 – 6.197)
.030 p.005
TYP
1
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020
s 45o
(0.254 – 0.508)
.008 – .010
(0.203 – 0.254)
0o– 8o TYP
.016 – .050
(0.406 – 1.270)
NOTE:
1. DIMENSIONS IN
.053 – .069
(1.346 – 1.752)
.014 – .019
(0.355 – 0.483)
TYP
INCHES
(MILLIMETERS)
2. DRAWING NOT TO SCALE
3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS.
MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
2
3
4
.004 – .010
(0.101 – 0.254)
.050
(1.270)
BSC
SO8 0303
18189fb
16
LT1818/LT1819
REVISION HISTORY
(Revision history begins at Rev B)
REV
DATE
DESCRIPTION
PAGE NUMBER
B
5/10
Updated Order Information Section
2
18189fb
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.
17
LT1818/LT1819
TYPICAL APPLICATION
80MHz, 20dB Gain Block
+
VIN
1/2 LT1819
–
+
VOUT
1/2 LT1819
432Ω
–
432Ω
200Ω
200Ω
–3dB BANDWIDTH: 80MHz
18189 TA03
20dB Gain Block Frequency Response
Large-Signal Transient Response
25
20
GAIN (dB)
15
10
1V/DIV
5
0
–5
VS = ±5V
TA = 25°C
–10
100k
1M
10M
FREQUENCY (Hz)
10ns/DIV
100M
18189 TA07
18189 TA04
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
LT1395/LT1396/LT1397
Single/Dual/Quad 400MHz Current Feedback Amplifiers
4.6mA Supply Current
LT1806/LT1807
Single/Dual 325MHz, 140V/μs Rail-to-Rail I/O Op Amps
Low Noise: 3.5nV/√Hz
LT1809/LT1810
Single/Dual 180MHz, 350V/μs Rail-to-Rail I/O Op Amps
Low Distortion: –90dBc at 5MHz
LT1812/LT1813/LT1814
Single/Dual/Quad 100MHz, 750V/μs Op Amps
Low Power: 3.6mA Max at ±5V
LT1815/LT1816/LT1817
Single/Dual/Quad 220MHz, 1500V/μs Op Amps
Programmable Supply Current
LT6203/LT6204
Dual/Quad 100MHz, Rail-to-Rail I/O Op Amps
1.9nV/√Hz Noise, 3mA Max
18189fb
18 Linear Technology Corporation
LT 0510 REV B • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
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