LT1818/LT1819 400MHz, 2500V/µs, 9mA Single/Dual Operational Amplifiers
FEATURES
s s s s s s s s s s s s s s
DESCRIPTIO
400MHz Gain Bandwidth Product 2500V/µs Slew Rate –85dBc Distortion at 5MHz 9mA Supply Current Per Amplifier Space Saving SOT-23 and MS8 Packages 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
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 unitygain 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. The LT1818/LT1819 are manufactured on Linear Technology’s advanced low voltage complementary bipolar process. The LT1818 (single op amp) is available in SOT-23 and SO-8 packages; the LT1819 (dual op amp) is available in MSOP-8 and SO-8 packages.
, LTC and LT are registered trademarks of Linear Technology Corporation.
APPLICATIO S
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Wideband Amplifiers Buffers Active Filters Video and RF Amplification Communication Receivers Cable Drivers Data Acquisition Systems
TYPICAL APPLICATIO
FFT of Single Supply ADC Driver Single Supply Unity-Gain ADC Driver for Oversampling Applications
5V 2.5VDC ±1VAC 5V 51.1Ω LT1818 18pF
0 –10 –20 –30
AMPLITUDE (dBc)
+ –
AIN+ 2.5V AIN–
LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE)
–40 –50 –60 –70 –80 –90 2
18189 TA01
–100 –110 0 5M 10M 15M 20M FREQUENCY (Hz) 25M
18189 TA02
U
fIN = 5.102539MHz fS = 50Msps VIN = 300mVP-P SFDR = 78dB 8192 POINT FFT NO WINDOWING OR AVERAGING 3
18189f
U
U
1
LT1818/LT1819
ABSOLUTE
(Note 1)
AXI U
RATI GS
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
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
PACKAGE/ORDER I FOR ATIO
TOP VIEW OUT 1 1 V– 2 +IN 3 + – 4 –IN 5 V+
ORDER PART NUMBER LT1818CS5 LT1818IS5 S5 PART* MARKING LTF7 ORDER PART NUMBER
S5 PACKAGE 5-LEAD PLASTIC SOT-23
TJMAX = 150°C, θJA = 250°C/W (NOTE 10)
TOP VIEW NC 1 –IN 2 +IN 3 V– 4 – + 8 7 6 5 NC V+ OUT NC
LT1818CS8 LT1818IS8 S8 PART MARKING 1818 1818I
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 150°C/W (NOTE 10)
*The temperature grade is identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS
SYMBOL VOS PARAMETER Input Offset Voltage
The q 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.
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) TA = 0°C to 70°C TA = – 40°C to 85°C TA = 0°C to 70°C TA = –40°C to 85°C f = 10kHz f = 10kHz
q q q q q q
∆VOS/∆T IOS
Input Offset Voltage Drift Input Offset Current
IB
Input Bias Current
en in
Input Noise Voltage Density Input Noise Current Density
2
U
U
W
WW
U
W
TOP VIEW OUT A –IN A +IN A V– 1 2 3 4 8 7 6 5 V+ OUT B –IN B +IN B
A B
ORDER PART NUMBER LT1819CMS8 LT1819IMS8 MS8 PART MARKING LTE7 LTE5 ORDER PART NUMBER
MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 250°C/W (NOTE 10)
TOP VIEW OUT A 1 –IN A 2 A +IN A 3 V– B 4 5 +IN B 6 –IN B 8 7 V+ OUT B
LT1819CS8 LT1819IS8 S8 PART MARKING 1819 1819I
S8 PACKAGE 8-LEAD PLASTIC SO
TJMAX = 150°C, θJA = 150°C/W (NOTE 10)
MIN
TYP 0.2
MAX 1.5 2.0 3.0 15 30 800 1000 1200 ±8 ±10 ±12
UNITS mV mV mV µV/°C µV/°C nA nA nA µA µA µA nV/√Hz pA/√Hz
18189f
10 10 60
–2
q q
6 1.2
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
SYMBOL RIN CIN VCM CMRR PARAMETER Input Resistance Input Capacitance Input Voltage Range (Positive/Negative) Common Mode Rejection Ratio
The q 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.
CONDITIONS VCM = V – + 1.5V to V + – 1.5V Differential 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) 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 MIN 1.5 TYP 5 750 1.5 ±4.2 85 ±1.25
q q q q q q q q q q q q q q q q q
MAX
q q q
±3.5 ±3.5 75 73 72
Minimum Supply Voltage PSRR Power Supply Rejection Ratio
±2 ±2
AVOL
Large-Signal Voltage Gain
Channel Separation
VOUT
Output Swing(Positive/Negative)
IOUT
Output Current
ISC
Output Short-Circuit Current
78 76 75 1.5 1.0 0.8 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 ±70 900 750 600 270 260 250
97
2.5
6
100 ±4.1 ±3.8 ± 70 ±200
SR
Slew Rate
2500 1800
q q
FPBW GBW
Full Power Bandwidth Gain Bandwidth Product
95 400
q q
tr, tf tPD OS tS HD dG dP IS
Rise Time, Fall Time Propagation Delay Overshoot Settling Time Harmonic Distortion Differential Gain Differential Phase Supply Current
0.6 1.0 20 10 –85 –89 0.07 0.02 9
q q
10 13 14
UNITS 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 MHz MHz MHz ns ns % ns dBc dBc % DEG mA mA mA
18189f
3
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
SYMBOL VOS PARAMETER Input Offset Voltage
The q 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.
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 TA = 0°C to 70°C TA = – 40°C to 85°C TA = 0°C to 70°C TA = –40°C to 85°C f = 10kHz f = 10kHz VCM Differential = V– + 1.5V to V + – 1.5V 1.5
q q q q q q
MIN
TYP 0.4
MAX 2.0 2.5 3.5 15 30 800 1000 1200 ±8 ±10 ±12
UNITS mV mV mV µV/°C µV/°C nA nA nA µA µA µA nV/√Hz pA/√Hz MΩ kΩ pF V V
∆VOS/∆T
Input Offset Voltage Drift
10 10 60
IOS
Input Offset Current
IB
Input Bias Current
–2.4
q q
en in RIN CIN VCM
Input Noise Voltage Density Input Noise Current Density Input Resistance Input Capacitance Input Voltage Range (Positive) Input Voltage Range (Negative)
6 1.4 5 750 1.5 4.2 0.8
q q q q q q q q q q q q q q q q q q
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 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
q
3.5 3.5
1.5 1.5
V V dB dB dB
CMRR
Common Mode Rejection Ratio
73 71 70
82
Minimum Supply Voltage PSRR Power Supply Rejection Ratio
±1.25 78 76 75 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 97
±2 ±2
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
AVOL
Large-Signal Voltage Gain
2
4
Channel Separation
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
100
VOUT
Output Swing(Positive)
4.2
4
Output Swing(Negative)
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
0.8
1.1 1.2 1.3 1.3 1.4 1.5
V V V V V V
18189f
1
q q
4
LT1818/LT1819
ELECTRICAL CHARACTERISTICS
SYMBOL IOUT PARAMETER Output Current
The q 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.
CONDITIONS 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 FPBW GBW Full Power Bandwidth Gain Bandwidth Product 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
q q q q q q q q q q
MIN ± 30 ± 25 ± 20 ±80 ± 70 ±50 450 375 300 240 230 220
TYP ± 50
MAX
UNITS mA mA mA mA mA mA V/µs V/µs V/µs V/µs MHz MHz MHz MHz ns ns % dBc dBc % DEG
ISC
Output Short-Circuit Current
±140
SR
Slew Rate
1000 800
125 360
tr, tf tPD OS HD dG dP IS
Rise Time, Fall Time Propagation Delay Overshoot Harmonic Distortion Differential Gain Differential Phase Supply Current
0.7 1.1 20 –72 –74 0.07 0.07 8.5 10 13 14
mA mA mA
Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. 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. 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: 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 6: Full power bandwidth is calculated from the slew rate: FPBW = SR/2πVP Note 7: This parameter is not 100% tested. Note 8: The LT1818C/LT1818I and LT1819C/LT1819I are guaranteed functional over the operating temperature range of – 40°C to 85°C. 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. 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.
18189f
5
LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Temperature
12 PER AMPLIFIER 10 VS = ± 5V VS = ± 2.5V 6 4 2 0 –50 –25 V+ – 0.5
INPUT COMMON MODE RANGE (V)
8
–1.5 – 2.0
INPUT BIAS CURRENT (µA)
SUPPLY CURRENT (mA)
50 25 0 75 TEMPERATURE (°C)
Input Bias Current vs Temperature
0 –0.4
VCM = 0V
INPUT VOLTAGE NOISE (nV/√Hz)
INPUT BIAS CURRENT (µA)
–0.8 –1.2 –1.6 –2.0 –2.4 –2.8 –50 –25 VS = ± 5V VS = ± 2.5V
OPEN-LOOP GAIN (dB)
50 25 75 0 TEMPERATURE (°C)
Open-Loop Gain vs Temperature
80 77
OPEN-LOOP GAIN (dB)
VS = ± 5V VO = ± 3V
OUTPUT VOLTAGE SWING (V)
–1.0 –1.5 – 2.0 RL = 100Ω
74 71 68 65 62 –50 –25 RL = 500Ω
OUTPUT VOLTAGE SWING (V)
RL = 100Ω
50 25 75 0 TEMPERATURE (°C)
6
UW
100 125
18189 G01
Input Common Mode Range vs Supply Voltage
TA = 25°C ∆VOS < 1mV 2
Input Bias Current vs Common Mode Voltage
TA = 25°C VS = ± 5V
–1.0
0
–2
2.0 1.5 1.0 0.5 V– 0 1 4 3 2 5 SUPPLY VOLTAGE (± V) 6 7
–4
–6
–8 –5
0 2.5 – 2.5 INPUT COMMON MODE VOLTAGE (V)
5
18189 G02
18189 G03
Input Noise Spectral Density
100 TA = 25°C VS = ± 5V AV = 101 RS = 10k in 10 en 1 10
INPUT CURRENT NOISE (pA/√Hz)
Open-Loop Gain vs Resistive Load
80 77 74 71 68 65 VS = ± 2.5V 62 100 TA = 25°C
VS = ± 5V
1
100 125
10
100
1k 10k FREQUENCY (Hz)
0.1 100k
18189 G05
1k LOAD RESISTANCE (Ω)
10k
18189 G06
18189 G04
Output Voltage Swing vs Supply Voltage
V+ – 0.5 TA = 25°C ∆VOS = 30mV RL = 500Ω
Output Voltage Swing vs Load Current
TA = 25°C VS = ± 5V ∆VOS = 30mV SOURCE 5
OUTPUT VOLTAGE SWING (V)
4
–2 SINK
3
2.0 1.5 1.0 0.5 V– RL = 500Ω 0 1 4 3 2 5 SUPPLY VOLTAGE (± V) 6 7 RL = 100Ω
–3
2
–4
100
125
–5 –120
–80
0 40 80 –40 OUTPUT CURRENT (mA)
120
18189 G09
18189 G07
18189 G08
18189f
LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS
Output Short-Circuit Current vs Temperature
240
OUTPUT SHORT-CIRCUIT CURRENT (mA)
VS = ± 5V VIN = ± 1V
SOURCE 125 SINK
OUTUPT CURRENT (mA) OUTPUT IMPEDANCE (Ω)
200 160 120 80 40 0 –50 –25
50 25 75 0 TEMPERATURE (°C)
Gain and Phase vs Frequency
80 70 60 50 PHASE
GAIN (dB)
GAIN BANDWIDTH (MHz)
40 30 20 10
TA = 25°C –10 AV = –1 RL = 500Ω –20 100k 10k
0
1M 10M FREQUENCY (Hz)
Gain vs Frequency, AV = 1
5 TA = 25°C AV = 1 RL = 500Ω 10 VS = ± 2.5V VS = ± 5V 5 0
GAIN (dB)
GAIN (dB)
0
–5
GAIN (dB)
–10 1M
10M 100M FREQUENCY (Hz)
UW
100
18189 G10
Output Current vs Temperature
150
Output Impedance vs Frequency
100
SOURCE, VS = ± 5V SINK, VS = ± 5V SOURCE, VS = ±2.5V
10
AV = 100 AV = 10
100 75
1
SINK, VS = ± 2.5V 50 25 ∆VOS = 30mV VOUT = ± 3V FOR VS = ± 5V VOUT = ± 1V FOR VS = ± 2.5V 50 25 75 0 TEMPERATURE (˚C) 100 125
0.1
AV = 1 TA = 25°C VS = ± 5V 100k 1M 10M FREQUENCY (Hz) 100M
18189 G12
125
0 –50 –25
0.01 10k
18189 G11
Gain Bandwidth and Phase Margin vs Temperature
180 160 140 120 400
PHASE (DEG)
440
RL = 500Ω
GBW VS = ± 5V
PHASE MARGIN (DEG)
GAIN 100 80 60 40 20 0 100M –20 500M
360
GBW VS = ± 2.5V
PHASE MARGIN VS = ± 2.5V
PHASE MARGIN VS = ± 5V
50
40
–50 –25
50 0 75 25 TEMPERATURE (°C)
100
30 125
18189 G13
18189 G15
Gain vs Frequency, AV = 2
RL = 500Ω 5
Gain vs Frequency, AV = – 1
VS = ± 2.5V VS = ± 5V
RL = 100Ω
0
500M
18189 G16
TA = 25°C –5 A = 2 V VS = ± 5V RF = RG = 500Ω CF = 1pF –10 10M 1M FREQUENCY (Hz)
–5 TA = 25°C AV = –1 RL = RF = RG = 500Ω 100M 300M –10 1M 10M FREQUENCY (Hz) 100M 300M
18189 G17
18189 G18
18189f
7
LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS
Gain Bandwidth and Phase Margin vs Supply Voltage
450 400
POWER SUPPLY REJECTION RATIO (dB)
80 PSRR 60 +PSRR
COMMON MODE REJECTION RATIO (dB)
TA = 25°C
GBW RL = 500Ω
GAIN BANDWIDTH (MHz)
350 300 GBW RL = 100Ω PHASE MARGIN RL = 100Ω PHASE MARGIN RL = 500Ω 2 5 4 3 SUPPLY VOLTAGE (± V) 6
18189 G19
Slew Rate vs Input Step
2000 TA =25°C AV = – 1 V = ± 5V 1600 RS = R = R = 500Ω F G L SLEW RATE (V/µs) SLEW RATE (V/µs) SR + 1200 SR –
SLEW RATE (V/µs)
800
400
0 2 3 4 5 INPUT STEP (VP-P) 6
18189 G22
Differential Gain and Phase vs Supply Voltage
TA = 25°C
DIFFERENTIAL PHASE (DEG)
DIFFERENTIAL GAIN RL = 150Ω 0.12 0.10 0.08 0.06 0.04 0.02 0 2 4 3 5 SUPPLY VOLTAGE (± V) 6
18189 G25
DISTORTION (dB)
–80 –90 –100 –110 AV = 2 VS = ± 5V VO = 2VP-P
DISTORTION (dB)
DIFFERENTIAL PHASE RL = 150Ω
8
UW
Power Supply Rejection Ratio vs Frequency
100 TA = 25°C AV = 1 VS = ± 5V 100
Common Mode Rejection Ratio vs Frequency
TA = 25°C
80 VS = ± 2.5V 60 VS = ± 5V
PHASE MARGIN (DEG)
45 40 35 30
40
40
20
20
0 1k 10k 1M 100k FREQUENCY (Hz) 10M 100M
18189 G20
0 1k 10k 1M 100k FREQUENCY (Hz) 10M 100M
18189 G21
Slew Rate vs Supply Voltage
2000 TA =25°C AV = – 1 RF = RG = RL = 500Ω
2400
Slew Rate vs Temperature
VIN = 6VP-P
2000 1600 1200 800 400
VS = ± 5V
1500
1000 VIN = 2VP-P 500
VS = ± 2.5V
0 0 1 4 3 2 5 SUPPLY VOLTAGE (± V) 6 7
0 –50 –25
AV = –1 RF = RG = RL = 500Ω 50 25 75 0 TEMPERATURE (°C) 100 125
18189 G23
18189 G24
Distortion vs Frequency, AV = 2
–60
0.10 0.08
Distortion vs Frequency, AV = –1
–60 2ND, RL = 100 –70 –80 –90 –100 –110 AV = – 1 VS = ± 5V VO = 2VP-P 2M 5M FREQUENCY (Hz) 10M
18189 G27
2ND, RL = 100 –70 3RD, RL = 100 2ND, RL = 500
DIFFERENTIAL GAIN (%)
0.06 0.04 0.02 0
2ND, RL = 500 3RD, RL = 500
3RD, RL = 500
3RD, RL = 100
–120 1M
2M 5M FREQUENCY (Hz)
10M
18189 G26
–120 1M
18189f
LT1818/LT1819 TYPICAL PERFOR A CE CHARACTERISTICS
Distortion vs Frequency, AV = 1
–60 –70 AV = 1 VS = ± 5V VO = 2VP-P 3RD, RL = 100
110 100
CHANNEL SEPARATION (dB)
2ND, RL = 100
DISTORTION (dB)
–80 –90 –100
3RD, RL = 500 –110 2ND, RL = 500 –120 1M 2M 5M FREQUENCY (Hz) 10M
18189 G28
Small-Signal Transient, 20dB Gain
20mV/DIV
Large-Signal Transient, AV = 1
1V/DIV
VS = ±5V
UW
10ns/DIV 10ns/DIV
Channel Separation vs Frequency
0.1% Settling Time
INPUT TRIGGER (1V/DIV) OUTPUT SETTLING RESIDUE (5mV/DIV)
90 80 70 60 50 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
18188 G29
Large-Signal Transient, AV = – 1
2V/DIV
18189 G31
VS = ±5V
5ns/DIV
18189 G32
Large-Signal Transient, AV = – 1
1V/DIV
18189 G33
VS = ±5V
10ns/DIV
18189 G34
18189f
9
LT1818/LT1819
APPLICATIO S I FOR ATIO
Layout and Passive Components
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. 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 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. In high closed-loop gain configurations, RF >> RG, and no CF need to be added. To optimize the bandwidth in these applications, a capacitance, 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 + RG CG RF CF
IN –
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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. Input Considerations 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 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.
+ –
RS CLOAD
18189 F01
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Figure 1
18189f
LT1818/LT1819
APPLICATIO S I FOR ATIO
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: PDMAX = (V + – V –) • (ISMAX) + (V+/2)2/RL or PDMAX = (V + – V –) • (ISMAX) + (V+ – VOMAX) • (VOMAX/RL)
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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.
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LT1818/LT1819
TYPICAL APPLICATIO
10µF VIN
5V
AMPLITUDE (dBc)
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Single Supply Differential ADC Driver
5V
+
1/2 LT1819
51.1Ω
18pF 5V
–
AIN+ 536Ω 536Ω 18pF AIN– LTC1744 14 BITS 50Msps (SET FOR 2VP-P FULL SCALE)
–
1/2 LT1819
51.1Ω 18pF
4.99k
+
4.99k 0.1µF
18189 TA05
Results Obtained with the Circuit of Figure 2 at 5MHz. FFT Shows 81dB Overall Spurious Free Dynamic Range
0 –10 –20 –30 –40 –50 –60 –70 –80 –90 –100 –110 –120 0 5M 10M 15M 20M FREQUENCY (Hz) 25M
18189 TA06
fIN = 5.023193MHz fS = 50Msps VIN = 750mVP-P
8192 SAMPLES NO WINDOWING NO AVERAGING
18189f
LT1818/LT1819
SI PLIFIED SCHE ATIC
V+
–IN C
V–
18189 SS
PACKAGE DESCRIPTIO
5.23 (.206) MIN
0.42 ± 0.04 (.0165 ± .0015) TYP
RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 0° – 6° TYP 4.90 ± 0.15 (1.93 ± .006) 3.00 ± 0.102 (.118 ± .004) NOTE 4
0.254 (.010) GAUGE PLANE
0.18 (.077) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 0.13 ± 0.076 (.005 ± .003)
MSOP (MS8) 0802
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
18189f
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(One Amplifier)
R1
+IN OUT
MS8 Package 8-Lead Plastic MSOP
(Reference LTC DWG # 05-08-1660)
0.889 ± 0.127 (.035 ± .005)
3.2 – 3.45 (.126 – .136)
0.65 (.0256) BSC
3.00 ± 0.102 (.118 ± .004) (NOTE 3)
8
7 65
0.52 (.206) REF
0.53 ± 0.015 (.021 ± .006) DETAIL “A”
1 1.10 (.043) MAX
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4 0.86 (.034) REF
0.65 (.0256) BSC
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LT1818/LT1819
PACKAGE DESCRIPTIO
0.62 MAX
0.95 REF
3.85 MAX 2.62 REF
RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR
0.20 BSC 0.90 – 1.45 DATUM ‘A’
0.35 – 0.55 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. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
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S5 Package 5-Lead Plastic SOT-23
(Reference LTC DWG # 05-08-1633)
2.80 – 3.10 (NOTE 4) 1.22 REF 1.4 MIN 2.60 – 3.00 1.50 – 1.75 (NOTE 4) PIN ONE 0.25 – 0.50 TYP 5 PLCS NOTE 3 0.95 BSC 0.90 – 1.30 0.00 – 0.15 1.90 BSC
S5 SOT-23 0502
ATTENTION: ORIGINAL SOT23-5L PACKAGE. MOST SOT23-5L PRODUCTS CONVERTED TO THIN SOT23 PACKAGE, DRAWING # 05-08-1635 AFTER APPROXIMATELY APRIL 2001 SHIP DATE
18189f
LT1818/LT1819
PACKAGE DESCRIPTIO
.050 BSC 8 N N .245 MIN .160 ±.005 .228 – .244 (5.791 – 6.197) 1 .030 ±.005 TYP 2 3 N/2
RECOMMENDED SOLDER PAD LAYOUT
.010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) 0°– 8° TYP
.016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN
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)
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.
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S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 ±.005 .189 – .197 (4.801 – 5.004) NOTE 3 7 6 5 .150 – .157 (3.810 – 3.988) NOTE 3 N/2 1 2 3 4 .053 – .069 (1.346 – 1.752) .004 – .010 (0.101 – 0.254) .014 – .019 (0.355 – 0.483) TYP .050 (1.270) BSC
SO8 0502
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LT1818/LT1819
TYPICAL APPLICATIO
20dB Gain Block Frequency Response
25 20 15
GAIN (dB)
10 5 0 –5 VS = ± 5V TA = 25°C 1M 10M FREQUENCY (Hz) 100M
18189 TA04
–10 100k
RELATED PARTS
PART NUMBER LT1395/LT1396/LT1397 LT1806/LT1807 LT1809/LT1810 LT1812/LT1813/LT1814 LT1815/LT1816/LT1817 LT6203/LT6204 DESCRIPTION Single/Dual/Quad 400MHz Current Feedback Amplifiers Single/Dual 325MHz, 140V/µs Rail-to-Rail I/O Op Amps Single/Dual 180MHz, 350V/µs Rail-to-Rail I/O Op Amps Single/Dual/Quad 100MHz, 750V/µs Op Amps Single/Dual/Quad 220MHz, 1500V/µs Op Amps Dual/Quad 100MHz, Rail-to-Rail I/O Op Amps COMMENTS 4.6mA Supply Current Low Noise: 3.5nV/√Hz Low Distortion: –90dBc at 5MHz Low Power: 3.6mA Max at ±5V Programmable Supply Current 1.9nV/√Hz Noise, 3mA Max
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 q FAX: (408) 434-0507
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80MHz, 20dB Gain Block
+
1/2 LT1819 VIN
+
1/2 LT1819 VOUT
–
432Ω 200Ω
–
432Ω 200Ω
–3dB BANDWIDTH: 80MHz
18189 TA03
Large-Signal Transient Response
1V/DIV
10ns/DIV
18189 TA07
18189f LT/TP 0103 2K • PRINTED IN USA
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© LINEAR TECHNOLOGY CORPORATION 2002
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