LINER LT1782CS6

LT1782
Micropower, Over-The-Top
SOT-23, Rail-to-Rail
Input and Output Op Amp
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DESCRIPTIO
FEATURES
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Operates with Inputs Above V +
Rail-to-Rail Input and Output
Micropower: 55µA Supply Current Max
Small SOT-23 Package
Low Input Offset Voltage: 800µV Max
Single Supply Input Range: 0V to 18V
High Output Current: 18mA Min
Specified on 3V, 5V and ±5V Supplies
Output Shutdown on 6-Lead Version
Reverse Battery Protection to 18V
High Voltage Gain: 1500V/mV
Gain Bandwidth Product: 200kHz
Slew Rate: 0.07V/µs
Operating Temperature Range: –40°C to 85°C
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APPLICATIO S
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The input range of the LT1782 includes ground, and a
unique feature of this device is its Over-The-TopTM operation capability with either or both of its inputs above the
positive rail. The inputs handle 18V both differential and
common mode, independent of supply voltage. The input
stage incorporates phase reversal protection to prevent
false outputs from occurring even when the inputs are 9V
below the negative supply.
The LT1782 can drive loads up to 18mA and still maintain
rail-to-rail capability. A shutdown feature on the 6-lead
version can disable the part, making the output high
impedance and reducing quiescent current to 5µA. The
LT1782 op amp is available in the 5- and 6-lead
SOT-23 packages. For applications requiring higher speed,
refer to the LT1783.
Portable Instrumentation
Battery- or Solar-Powered Systems
Sensor Conditioning
Supply Current Sensing
Battery Monitoring
MUX Amplifiers
4mA to 20mA Transmitters
, LTC and LT are registered trademarks of Linear Technology Corporation.
Over-The-Top is a trademark of Linear Technology Corporation.
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The LT®1782 is a 200kHz op amp available in the small
SOT-23 package that operates on all single and split
supplies with a total voltage of 2.5V to 18V. The amplifier
draws less than 55µA of quiescent current and has reverse
battery protection, drawing negligible current for reverse
supply voltages up to 18V.
TYPICAL APPLICATIO
Distribution of Input Offset Voltage
Positive Supply Rail Current Sense
200Ω
5V
0.2Ω
200Ω
LOAD
ILOAD
+
LT1782
2N3904
–
VOUT = 2Ω(ILOAD)
0V TO 4.3V
PERCENTAGE OF AMPLIFIERS
V+
5V TO 18V
25
20
VS = 5V, 0V
VCM = 2.5V
15
10
5
2k
1782 TA01
0
–900
–600 –300
0
300
600
INPUT OFFSET VOLTAGE (µV)
900
1782 TA01a
1
LT1782
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ABSOLUTE MAXIMUM RATINGS
(Note 1)
Total Supply Voltage (V + to V –) .............................. 18V
Input Differential Voltage ........................................ 18V
Input Pin Voltage to V – ............................... + 24V/–10V
Shutdown Pin Voltage Above V – ............................ 18V
Shutdown Pin Current ....................................... ±10mA
Output Short-Circuit Duration (Note 2) ........... Indefinite
Operating Temperature Range (Note 10) – 40°C to 85°C
Specified Temperature Range ...................... 0°C to 70°C
Junction Temperature........................................... 150°C
Storage Temperature Range ................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
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PACKAGE/ORDER INFORMATION
TOP VIEW
5 V
OUT 1
V– 2
+
OUT 1
LT1782CS5
+IN 3
+ –
+IN 3
4 –IN
S5 PACKAGE
5-LEAD PLASTIC SOT-23
TOP VIEW
ORDER PART
NUMBER
V– 2
S5 PART MARKING
LTLD
TJMAX = 150°C, θJA = 250°C/ W
ORDER PART
NUMBER
+
6 V
5 SHDN
+ –
LT1782CS6
4 –IN
S6 PART MARKING
S6 PACKAGE
6-LEAD PLASTIC SOT-23
LTIS
TJMAX = 150°C, θJA = 230°C/ W
Consult factory for Industrial and Military grade parts.
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C.
VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, for the 6-lead part VPIN5 = 0V, pulse power tested unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
VOS
TA = 25°C
0°C ≤ TA ≤ 70°C
●
0°C ≤ TA ≤ 70°C
VCM = 18V (Note 3)
Input Offset Voltage
Input Offset Voltage Drift (Note 7)
IOS
IB
Input Offset Current
Input Bias Current
VCM = 18V (Note 3)
SHDN or VS = 0V, VCM = 0V to 18V
MIN
TYP
MAX
UNITS
400
800
950
µV
µV
●
2
5
µV/°C
●
●
0.7
2
1
nA
µA
●
●
8
6
0.1
15
12
nA
µA
nA
●
Input Bias Current Drift
0°C ≤ TA ≤ 70°C
0.01
nA/°C
Input Noise Voltage
0.1Hz to 10Hz
1
µVP-P
en
Input Noise Voltage Density
f = 1kHz
50
nV/√Hz
in
Input Noise Current Density
f = 1kHz
0.05
pA/√Hz
RIN
Input Resistance
Differential
Common Mode, VCM = 0V to (VCC – 1V)
Common Mode, VCM = 0V to 18V
6.5
5
3
MΩ
GΩ
MΩ
CIN
3.4
1.5
Input Capacitance
5
Input Voltage Range
●
0
pF
18
V
CMRR
Common Mode Rejection Ratio
(Note 3)
VCM = 0V to VCC – 1V
VCM = 0V to 18V (Note 6)
●
●
90
68
100
80
dB
dB
PSRR
Power Supply Rejection Ratio
VS = 3V to 12.5V, VCM = VO = 1V
●
90
100
dB
AVOL
Large-Signal Voltage Gain
VS = 3V, VO = 500mV to 2.5V, RL = 10k
VS = 3V, 0°C ≤ TA ≤ 70°C
200
133
1500
●
V/mV
V/mV
VS = 5V, VO = 500mV to 4.5V, RL = 10k
VS = 5V, 0°C ≤ TA ≤ 70°C
400
250
1500
●
V/mV
V/mV
2
LT1782
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C.
VS = 3V, 0V; VS = 5V, 0V, VCM = VOUT = half supply, for the 6-lead part VPIN5 = 0V, pulse power tested unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
VOL
Output Voltage Swing LOW
No Load
ISINK = 5mA
VS = 5V, ISINK = 10mA
●
●
●
VOH
Output Voltage Swing HIGH
VS = 3V, No Load
VS = 3V, ISOURCE = 5mA
●
●
2.91
2.6
2.94
2.8
V
V
VS = 5V, No Load
VS = 5V, ISOURCE = 10mA
●
●
4.91
4.5
4.94
4.74
V
V
VS = 3V, Short to GND
VS = 3V, Short to VCC
5
15
10
30
mA
mA
VS = 5V, Short to GND
VS = 5V, Short to VCC
15
20
30
40
mA
mA
ISC
Short-Circuit Current (Note 2)
Minimum Supply Voltage
Reverse Supply Voltage
IS
MIN
Supply Current
(Note 4)
●
MAX
UNITS
3
200
400
8
500
800
mV
mV
mV
2.5
●
IS = –100µA
TYP
2.7
18
V
V
40
55
60
µA
µA
●
Supply Current, SHDN
VPIN5 = 2V, No Load (Note 8)
●
5
15
µA
Shutdown Pin Current
VPIN5 = 0.3V, No load (Note 8)
VPIN5 = 2V, No Load (Note 8)
VPIN5 = 5V, No Load (Note 8)
●
●
●
0.5
2
5
8
nA
µA
µA
Shutdown Output Leakage Current
VPIN5 = 2V, No Load (Note 8)
●
0.05
1
µA
Maximum Shutdown Pin Current
VPIN5 = 18V, No Load (Note 8)
●
10
30
µA
VL
Shutdown Pin Input Low Voltage
(Note 8)
●
0.3
V
VH
Shutdown Pin Input High Voltage
(Note 8)
●
tON
Turn-On Time
VPIN5 = 5V to 0V, RL = 10k (Note 8)
100
µs
tOFF
Turn-Off Time
VPIN5 = 0V to 5V, RL = 10k (Note 8)
6
µs
GBW
Gain Bandwidth Product
(Note 3)
f = 5kHz
0°C ≤ TA ≤ 70°C
110
100
200
●
kHz
kHz
Slew Rate
(Note 5)
AV = –1, RL = ∞
0°C ≤ TA ≤ 70°C
0.035
0.031
0.07
●
V/µs
V/µs
ISHDN
SR
tS
Settling Time
VS = 5V, ∆VOUT = 2V to 0.1%, AV = –1
THD
Distortion
VS = 3V, VO = 2VP–P, AV = 1, RL = 10k, f =1kHz
FPBW
Full-Power Bandwidth (Note 9)
VOUT = 2VP–P
2
V
45
µs
0.003
%
11
kHz
VS = ±5V, VCM = 0V,VOUT = 0V, for the 6-lead part VSHDN = V –
VOS
Input Offset Voltage
TA = 25°C
0°C ≤ TA ≤ 70°C
●
0°C ≤ TA ≤ 70°C
500
900
1050
µV
µV
●
2
5
µV/°C
IOS
Input Offset Current
●
0.7
2
nA
IB
Input Bias Current
●
8
15
nA
●
Input Offset Voltage Drift (Note 7)
Input Bias Current Drift
0°C ≤ TA ≤ 70°C
0.01
nA/°C
Input Noise Voltage
0.1Hz to 10Hz
1
µVP-P
en
Input Noise Voltage Density
f = 1kHz
50
nV/√Hz
in
Input Noise Current Density
f = 1kHz
0.05
pA/√Hz
3
LT1782
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the specified temperature range, otherwise specifications are TA = 25°C.
VS = ±5V, VCM = 0V,VOUT = 0V, for the 6-lead part VSHDN = V–, unless otherwise specified.
SYMBOL PARAMETER
CONDITIONS
RIN
Input Resistance
Differential
Common Mode, VCM = –5V to 13V
CIN
Input Capacitance
MIN
TYP
●
●
3.4
1.5
6.5
3
●
–5
MAX
MΩ
MΩ
5
Input Voltage Range
UNITS
pF
13
V
CMRR
Common Mode Rejection Ratio
VCM = –5V to 13V
●
68
80
dB
AVOL
Large-Signal Voltage Gain
VO = ±4V, RL= 10k
0°C ≤ TA ≤ 70°C
55
40
150
●
V/mV
V/mV
VOL
Output Voltage Swing LOW
No Load
ISINK = 5mA
ISINK = 10mA
●
●
●
VOH
Output Voltage Swing HIGH
No Load
ISOURCE = 5mA
ISOURCE = 10mA
●
●
●
4.91
4.6
4.5
4.94
4.8
4.74
ISC
Short-Circuit Current (Note 2)
Short to GND
0°C ≤ TA ≤ 70°C
18
15
30
●
VS = ±1.5V to ±9V
●
90
100
PSRR
Power Supply Rejection Ratio
IS
Supply Current
–4.997
–4.8
–4.6
V
V
V
V
V
V
mA
mA
dB
45
60
65
µA
µA
●
ISHDN
–4.992
–4.5
–4.2
Supply Current, SHDN
VPIN5 = –3V, VS = ±5V, No Load (Note 8)
●
6
20
µA
Shutdown Pin Current
VPIN5 = –4.7V, VS = ±5V, No load (Note 8)
VPIN5 = –3V, VS = ±5V, No Load (Note 8)
●
●
0.5
2
8
nA
µA
VPIN5 = 9V, VS = ±9V (Note 8)
●
10
30
µA
0.05
1
µA
–4.7
V
Maximum Shutdown Pin Current
Shutdown Output Leakage Current
VPIN5 = –7V, VS = ±9V, No Load (Note 8)
●
VL
Shutdown Pin Input Low Voltage
VS = ±5V (Note 8)
●
VH
Shutdown Pin Input High Voltage
VS = ±5V (Note 8)
●
tON
Turn-On Time
VPIN5 = 0V to –5V, RL = 10k (Note 8)
●
100
µs
tOFF
Turn-Off Time
VPIN5 = –5V to 0V, RL = 10k (Note 8)
●
6
µs
GBW
Gain Bandwidth Product
f = 5kHz
0°C ≤ TA ≤ 70°C
120
110
225
●
kHz
kHz
AV = –1, RL = ∞, VO = ±4V, Measured at VO = ±2V
0°C ≤ TA ≤ 70°C
0.0375
0.033
0.075
●
V/µs
V/µs
SR
Slew Rate
–3
V
tS
Settling Time
∆VOUT = 4V to 0.1%, AV = 1
50
µs
FPBW
Full-Power Bandwidth (Note 9)
VOUT = 8VP–P
3
kHz
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 to keep the junction temperature
below absolute maximum.
Note 3: VS = 5V limits are guaranteed by correlation to VS = 3V and
VS = ±5V or VS = ±9V tests.
Note 4: VS = 3V limits are guaranteed by correlation to VS = 5V and
VS = ±5V or VS = ±9V tests.
Note 5: Guaranteed by correlation to slew rate at VS = ±5V, and GBW at
VS = 3V and VS = ±5V tests.
4
Note 6: This specification implies a typical input offset voltage of 1.8mV at
VCM = 18V and a maximum input offset voltage of 7.2mV at VCM = 18V.
Note 7: This parameter is not 100% tested.
Note 8: Specifications apply to 6-lead SOT-23 with shutdown.
Note 9: Full-power bandwidth is calculated for the slew rate.
FPBW = SR/2πVP.
Note 10: The LT1782 is guaranteed functional over the operating
temperature range – 40°C to 85°C.
LT1782
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TYPICAL PERFOR A CE CHARACTERISTICS
50
400
INPUT OFFSET VOLTAGE CHANGE (µV)
40
TA = 25°C
35
TA = –55°C
30
25
4
6
8
10 12 14
SUPPLY VOLTAGE (V)
16
4
200
100
0
TA = 125°C
TA = –55°C
–100
–400
18
0
1
2
3
4
TOTAL SUPPLY VOLTAGE (V)
1782 G02a
Output Saturation Voltage vs Load
Current (Output Low)
1
1
VS = 5V, 0V
2000
TA = 25°C
1000
40
30
VS = ±2.5V
VOD = 30mV
OUTPUT SATURATION VOLTAGE (V)
3000
TA = –55°C
20
10
0
–10
15 16 18
3.8 4 4.2 4.4 4.6 4.8 5 5.2 5.4
COMMON MODE VOLTAGE (V)
–
0
–10–8 –6 –4 –2 0 2 4 6 8 10 12 14 16 18
VIN (V)
5
Output Saturation Voltage vs Load
Current (Output High)
TA = 125°C
+
1782 G02
6000
TA = 125°C
0.1
TA = 25°C
0.01
1µ
TA = –55°C
VS = ±2.5V
VOD = 30mV
TA = 125°C
0.1
TA = –55°C
TA = 25°C
0.01
0.001
10µ
100µ
1m
SOURCING LOAD CURRENT (A)
1782 G03
10m
10µ
1µ
1m
SINKING LOAD CURRENT (A)
1µ
1782 G05
1782 G04
Output Saturation Voltage vs
Input Overdrive
10m
Output Short-Circuit Current vs
Temperature
0.1Hz to 10Hz Noise Voltage
40
100
VS = ±5V
OUTPUT HIGH
VS = ±2.5V
OUTPUT CURRENT (mA)
35
10
OUTPUT LOW
1
10
20
30
40
50
INPUT OVERDRIVE (mV)
SINKING CURRENT
30
SOURCING CURRENT
25
20
VS = ±2.5V
NO LOAD
0
NOISE VOLTAGE (400nV/DIV)
INPUT BIAS CURRENT (nA)
VIN
1
Input Bias Current vs Common
Mode Voltage
4000
5V
2
–300
1782 G01
5000
3
TA = 25°C
–200
20
2
VS = 5V, 0V
300
OUTPUT SATURATION VOLTAGE (V)
SUPPLY CURRENT (µA)
45
5
VOUT (V)
TA = 125°C
OUTPUT SATURATION VOLTAGE (mV)
Output Voltage vs Large Input
Voltage
Minimum Supply Voltage
Supply Current vs Supply Voltage
60
1782 G06
15
–50
–25
0
25
50
75
TEMPERATURE (°C)
100
125
1782 G06a
0
1
2
3
4 5 6
TIME (sec)
7
8
9
10
1782 G07
5
LT1782
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TYPICAL PERFOR A CE CHARACTERISTICS
Noise Voltage Density vs
Frequency
70
70
60
50
40
30
1
100
1k
FREQUENCY (Hz)
10
10k
VS = ±2.5V
0.35
50
0.30
0.25
0.20
0.10
20
GAIN
20
0
10
–20
0
–40
–10
–60
0.05
–20
–80
0
–30
1
10
100
1k
FREQUENCY (Hz)
–100
1M
10k
100k
FREQUENCY (Hz)
1k
10k
1782 G10
Gain Bandwidth Product and
Phase Margin vs Supply Voltage
Slew Rate vs Temperature
VS = ±2.5V
0.10
200
190
180
GAIN BAINDWIDTH PRODUCT (kHz)
SLEW RATE (V/µs)
210
0.09
0.08
FALLING
0.07
0.06
0.05
–25
0
25
50
75
TEMPERATURE (°C)
100
0.04
–50
125
–25
0
25
50
75
TEMPERATURE (°C)
100
1782 G11
200
50
GAIN BANDWIDTH PRODUCT
150
100
10k
LOAD RESISTANCE (Ω)
100k
1782 G14
AV = –1
RF = RG = 10k
f = 5kHz
180
160
0
125
2
4
6
8 10 12 14 16
TOTAL SUPPLY VOLTAGE (V)
CMRR vs Frequency
110
VS = ±2.5V
80
70
60
50
POSITIVE SUPPLY
40
30
20
10
18
1782 G13
NEGATIVE SUPPLY
0
–10
50
1k
GAIN BANDWIDTH PRODUCT
200
90
POWER SUPPLY REJECTION RATIO (dB)
60
PHASE MARGIN (DEG)
250
220
PSRR vs Frequency
70
VS = ±2.5V
AV = –1
RF = RG = 10k
f = 5kHz
50
1782 G12
Gain Bandwidth Product and
Phase Margin vs Load Resistance
PHASE MARGIN
240
COMMON MODE REJECTION RATIO (dB)
170
–50
55
PHASE MARGIN
RISING
PHASE MARGIN (DEG)
60
0.11
f = 5kHz
VS = ±2.5V
220
GAIN BANDWIDTH (kHz)
30
0.15
Gain Bandwidth Product vs
Temperature
GAIN BANDWIDTH PRODUCT (kHz)
60
40
1782 G09
230
80
PHASE
40
1782 G08
6
100
VS = ±2.5V
60
GAIN (dB)
INPUT NOISE CURRENT DENSITY (pA/√Hz)
0.40
PHASE SHIFT (DEG)
INPUT NOISE VOLTAGE DENSITY (nV/√Hz)
80
20
Gain and Phase Shift vs
Frequency
Input Noise Current vs Frequency
VS = ±2.5V
100
90
80
70
60
50
40
30
1k
10k
100k
FREQUENCY (Hz)
1M
1782 G15
1k
10k
FREQUENCY (Hz)
100k
1782 G16
LT1782
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TYPICAL PERFOR A CE CHARACTERISTICS
Disabled Output Impedance vs
Frequency (Note 8)
Output Impedance vs Frequency
1M
10k
4
VS = ±2.5V
VPIN5 (SHUTDOWN) = 2.5V
VS = ±2.5V
AV = 10
100
10
AV = 1
3
100k
AV = 1
AV = –1
2
OUTPUT STEP (V)
OUTPUT IMPEDANCE (Ω)
AV = 100
1k
OUTPUT IMPEDANCE (Ω)
Settling Time to 0.1% vs Output
Step
10k
1k
1
VS = ±5V
0
–1
–2
1
AV = 1
AV = –1
–3
0.1
100
1k
10k
100k
FREQUENCY (Hz)
100
100
1M
1k
10k
100k
FREQUENCY (Hz)
VS = ±5V
10
OUTPUT SWING (VP-P)
30
25
20
AV = 1
AV = 5
10
AV = 10
5
70
80
1
DISTORTION ≤ 1%
AV = 1
8
THD + NOISE (%)
VS = 5V, 0V
VCM = 2.5V
15
35
40
50
60
SETTLING TIME (µs)
Total Harmonic Distortion + Noise
vs Frequency
12
40
35
30
1782 G18
Undistorted Output Swing vs
Frequency
Capacitive Load Handling
Overshoot vs Capacitive Load
6
4
VS = ±1.5V
VS = 3V, 0V
VOUT = 2VP-P
VCM = 1.2V
RL = 10k
0.1
AV = –1
RF = RG = 100k
0.010
2
AV = 1
10
100
1000
CAPACITIVE LOAD (pF)
0.001
0
100
0
10000
1k
10k
FREQUENCY (Hz)
10
10
f = 1kHz, RL = 10k
VS = 3V TOTAL
AV = 1
VIN = 2VP-P AT 1kHz
THD + NOISE (%)
VS = 3V, 0V
VIN = 0.5V TO 2.5V
0.01
0.001
100
AV = 1
VS = ±1.5V
VCM = 0V
1
0.1
AV = –1, RF = RG = 100k
VS = ±1.5V
VCM = 0V
0.1
0.01
VS = 3V, 0V
VIN = 0.2V TO 2.2V
AV = 1
VS = 3V. 0V
VCM = 1.5V
0.001
1k
10k
LOAD RESISTANCE TO GROUND (Ω)
100k
1782 G22
1k
100
FREQUENCY (Hz)
10k
1782 G21
Total Harmonic Distortion + Noise
vs Output Voltage Amplitude
Total Harmonic Distortion + Noise
vs Load Resistance
VS = ±1.5V
VIN = ±1V
10
1782 G20
1782 G19
1
100k
0
AV = –1, RF = RG = 100k
VS = 3V, 0V
VCM = 1.5V
1
2
OUTPUT VOLTAGE AMPLITUDE (VP-P)
Open-Loop Gain
INPUT OFFSET VOLTAGE CHANGE (50µV/DIV)
OVERSHOOT (%)
25
1782 G17a
1782 G17
THD + NOISE (%)
–4
1M
3
1782 G23
VS = ±5V
RL = 10k
RL = 50k
RL = 2k
–6 –5 –4 –3 –2 –1 0 1 2 3
OUTPUT VOLTAGE (V)
4
5
6
1782 G24
7
LT1782
U W
TYPICAL PERFOR A CE CHARACTERISTICS
Supply Current vs Shutdown
Voltage
Small-Signal Response
Large-Signal Response
50
VS = 5V, 0V
TA = 125°C
SUPPLY CURRENT (µA)
40
TA = 25°C
30
TA = –55°C
20
10
0
0
0.5
1
1.5
2
SHUTDOWN PIN VOLTAGE (V)
2.5
VS = ±5V
AV = 1
CL = 15pF
1782 G26
VS = ±5V
AV = 1
CL = 15pF
1782 G27
1782 G25
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APPLICATIO S I FOR ATIO
Supply Voltage
The positive supply pin of the LT1782 should be bypassed
with a small capacitor (typically 0.1µF) within an inch of
the pin. When driving heavy loads, an additional 4.7µF
electrolytic capacitor should be used. When using split
supplies, the same is true for the negative supply pin.
The LT1782 is protected against reverse battery voltages
up to 18V. In the event a reverse battery condition occurs,
the supply current is typically less than 1nA.
Inputs
The LT1782 has two input stages, NPN and PNP (see the
Simplified Schematic), resulting in three distinct operating regions as shown in the Input Bias Current vs Common
Mode typical performance curve.
For input voltages about 0.8V or more below V +, the PNP
input stage is active and the input bias current is typically
–8nA. When the input common mode voltage is within
0.5V of the positive rail, the NPN stage is operating and the
input bias current is typically 15nA. Increases in temperature will cause the voltage at which operation switches
from the PNP input stage to the NPN input stage to move
towards V +. The input offset voltage of the NPN stage is
untrimmed and is typically 1.8mV.
8
A Schottky diode in the collector of the input NPN transistors, along with special geometries for these NPN transistors, allows the LT1782 to operate with either or both of its
inputs above V +. At about 0.3V above V +, the NPN input
transistor is fully saturated and the input bias current is
typically 4µA at room temperature. The input offset voltage is typically 1.8mV when operating above V +. The
LT1782 will operate with its inputs 18V above V – regardless of V +.
The inputs are protected against excursions as much as
10V below V – by an internal 6k resistor in series with each
input and a diode from the input to the negative supply.
The input stage of the LT1782 incorporates phase reversal
protection to prevent the output from phase reversing for
inputs up to 9V below V –. There are no clamping diodes
between the inputs and the maximum differential input
voltage is 18V.
Output
The output of the LT1782 can swing to within 60mV of the
positive rail with no load and within 3mV of the negative
rail with no load. When monitoring voltages within 60mV
of the positive rail or within 3mV of the negative rail, gain
should be taken to keep the output from clipping. The
LT1782 can sink and source over 30mA at ±5V supplies,
LT1782
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APPLICATIO S I FOR ATIO
sourcing current is reduced to 10mA at 3V total supplies
as noted in the Electrical Characteristics.
The LT1782 is internally compensated to drive at least
600pF of capacitance under any output loading conditions. A 0.22µF capacitor in series with a 150Ω resistor
between the output and ground will compensate these
amplifiers for larger capacitive loads, up to 10,000pF, at all
output currents.
Distortion
There are two main contributors to distortion in op amps:
output crossover distortion as the output transitions from
sourcing to sinking current, and distortion caused by
nonlinear common mode rejection. If the op amp is
operating inverting, there is no common mode induced
distortion. If the op amp is operating in the PNP input stage
(input is not within 0.8V of V +), the CMRR is very good,
typically 100dB. When the LT1782 switches between
input stages, there is significant nonlinearity in the CMRR.
Lower load resistance increases the output crossover
distortion but has no effect on the input stage transition
distortion. For lowest distortion, the LT1782 should be
operated single supply, with the output always sourcing
current and with the input voltage swing between ground
and (V + – 0.8V). See the Typical Performance Characteristics curves, “Total Harmonic Distortion + Noise vs Ouput
Voltage Amplitude.”
Gain
The open-loop gain is almost independent of load when
the output is sourcing current. This optimizes performance in single supply applications where the load is
returned to ground. The typical performance curve of
open-loop gain for various loads shows the details.
Shutdown
The 6-lead part includes a shutdown feature that disables
the part, reducing quiescent current and making the
output high impedance. The part can be shut down by
bringing the SHDN pin 1.2V or more above V –. When shut
down, the supply current is about 5µA and the output
leakage current is less than 1µA (V – ≤ VOUT ≤ V +). In
normal operation, the SHDN pin can be tied to V – or left
floating. See the Typical Performance Characteristics
curves, “Supply Current vs Shutdown Pin Voltage.”
W
W
SI PLIFIED SCHE ATIC
V+
Q2
Q1
Q3
SHDN
R1
30k
R2
6k
Q4
Q19
– IN
Q17
+
J1
Q7
R3
6k
2µA
Q8
Q11
OUT
+IN
Q5
Q18
Q15
Q9
Q24
Q20
Q12
Q16
Q26
Q25 Q23
Q22
D3
D1
Q6
D4
D5
Q10
Q13
Q14
R4
40k
Q21
R5
40k
V–
1782 SS
9
LT1782
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PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S5 Package
5-Lead Plastic SOT-23
(LTC DWG # 05-08-1633)
2.80 – 3.00
(0.110 – 0.118)
(NOTE 3)
2.60 – 3.00
(0.102 – 0.118)
1.50 – 1.75
(0.059 – 0.069)
0.35 – 0.55
(0.014 – 0.022)
1.90
(0.074)
REF
0.00 – 0.15
(0.00 – 0.006)
0.09 – 0.20
(0.004 – 0.008)
(NOTE 2)
0.90 – 1.45
(0.035 – 0.057)
0.35 – 0.50
0.90 – 1.30
(0.014 – 0.020)
(0.035 – 0.051)
FIVE PLACES (NOTE 2)
S5 SOT-23 0599
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DIMENSIONS ARE INCLUSIVE OF PLATING
3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
4. MOLD FLASH SHALL NOT EXCEED 0.254mm
5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
10
0.95
(0.037)
REF
LT1782
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PACKAGE DESCRIPTIO
Dimensions in inches (millimeters) unless otherwise noted.
S6 Package
6-Lead Plastic SOT-23
(LTC DWG # 05-08-1634)
2.80 – 3.00
(0.110 – 0.118)
(NOTE 3)
PIN 1
1.90
(0.074)
REF
2.6 – 3.0
(0.110 – 0.118)
1.50 – 1.75
(0.059 – 0.069)
0.35 – 0.55
(0.014 – 0.022)
0.00 – 0.15
(0.00 – 0.006)
0.09 – 0.20
(0.004 – 0.008)
(NOTE 2)
0.95
(0.037)
REF
0.90 – 1.45
(0.035 – 0.057)
0.35 – 0.50
0.90 – 1.30
(0.014 – 0.020)
(0.035 – 0.051)
SIX PLACES (NOTE 2)
S6 SOT-23 0898
NOTE:
1. DIMENSIONS ARE IN MILLIMETERS
2. DIMENSIONS ARE INCLUSIVE OF PLATING
3. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR
4. MOLD FLASH SHALL NOT EXCEED 0.254mm
5. PACKAGE EIAJ REFERENCE IS SC-74A (EIAJ)
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
LT1782
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TYPICAL APPLICATIO S
Current Source
VCC
LT1634-1.25
R1
+
LT1782
2N3906
–
IOUT =
1.25V
R1
1782 TA02
Protected Fault Conditions
OK!
–18V
OK!
5V
V+
LT1782
LT1782
+
24V
REVERSE BATTERY
OK!
OK!
5V
+
LT1782
LT1782
10V
INPUT DIFFERENTIAL VOLTAGE
+
18V
5V
INPUT OVERVOLTAGE
INPUT BELOW GROUND
1782 TA03
RELATED PARTS
PART NUMBER
DESCRIPTION
COMMENTS
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Dual/Quad Over-The-Top Micropower Rail-to-Rail Input
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LT1636
Single Over-The-Top Micropower Rail-to-Rail Input
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VCC, MSOP Package, Shutdown Function
LT1638/LT1639
Dual/Quad, 1.2MHz, 0.4V/µs, Over-The-Top Micropower
Rail-to-Rail Input and Output Op Amps
170µA Supply Current, Single Supply Input Range: –0.4V to 44V,
Rail-to-Rail Input and Output
12
Linear Technology Corporation
1782f LT/TP 0400 4K • PRINTED IN USA
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com
 LINEAR TECHNOLOGY CORPORATION 1999