Datasheet LT1782 Datasheet (Linear Technology)

FEATURES

–900 –600 –300 0 300 600 900

PERCENTAGE OF AMPLIFIERS

INPUT OFFSET VOLTAGE (µV)

1782 TA01a

25

20

15

10

5

0

VS = 5V, 0V V

CM

= 2.5V

LT1782

Micropower, Over-The-Top

SOT-23, Rail-to-Rail

Input and Output Op Amp

U

DESCRIPTIO

■

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

+

U

APPLICATIO S

■

Portable Instrumentation

■

Battery- or Solar-Powered Systems

■

Sensor Conditioning

■

Supply Current Sensing

■

Battery Monitoring

■

MUX Amplifiers

■

4mA to 20mA Transmitters

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.

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.

, LTC and LT are registered trademarks of Linear Technology Corporation.

Over-The-Top is a trademark of Linear Technology Corporation.

TYPICAL APPLICATIO

Positive Supply Rail Current Sense

+

V

5V TO 18V

200Ω

LOAD

0.2Ω

200Ω

I

LOAD

+

LT1782

–

U

Distribution of Input Offset Voltage

5V

2N3904

V 0V TO 4.3V

2k

OUT

1782 TA01

= 2Ω(I

LOAD

)

1

LT1782

WW

W

ABSOLUTE MAXIMUM RATINGS

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

U

(Note 1)

Operating Temperature Range (Note 10) –40°C to 85°C

Specified Temperature Range ......................

Junction Temperature........................................... 150°C

Storage Temperature Range ................ –65°C to 150°C

Lead Temperature (Soldering, 10 sec)................. 300°C

Output Short-Circuit Duration (Note 2) ........... Indefinite

U

W

U

PACKAGE/ORDER INFORMATION

TOP VIEW

+

1

OUT

–

2

V

+IN

T

JMAX

Consult factory for Industrial and Military grade parts.

+

3

S5 PACKAGE

5-LEAD PLASTIC SOT-23

= 150°C, θJA = 250°C/ W

5

V

–

–IN

4

ORDER PART

LT1782CS5

S5 PART MARKING

NUMBER

LTLD

OUT

+IN

TOP VIEW

1

–

2

V

6-LEAD PLASTIC SOT-23

T

JMAX

+

3

= 150°C, θJA = 230°C/ W

–

S6 PACKAGE

+

V

6

SHDN

5

–IN

4

NUMBER

LT1782CS6

S6 PART MARKING

ORDER PART

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 = V

= half supply, for the 6-lead part V

OUT

= 0V, pulse power tested unless otherwise specified.

PIN5

0°C to 70°C

LTIS

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

OS

I

OS

I

B

e

n

i

n

R

IN

C

IN

CMRR Common Mode Rejection Ratio VCM = 0V to VCC – 1V ● 90 100 dB

PSRR Power Supply Rejection Ratio VS = 3V to 12.5V, VCM = VO = 1V ● 90 100 dB

A

VOL

Input Offset Voltage T

Input Offset Voltage Drift (Note 7) 0°C ≤ TA ≤ 70°C ● 25µV/°C Input Offset Current ● 0.7 2 nA

Input Bias Current ● 815 nA

Input Bias Current Drift 0°C ≤ TA ≤ 70°C ● 0.01 nA/°C Input Noise Voltage 0.1Hz to 10Hz 1 µV Input Noise Voltage Density f = 1kHz 50 nV/√Hz Input Noise Current Density f = 1kHz 0.05 pA/√Hz Input Resistance Differential 3.4 6.5 MΩ

Input Capacitance 5pF Input Voltage Range ● 018V

(Note 3) V

Large-Signal Voltage Gain VS = 3V, VO = 500mV to 2.5V, RL = 10k 200 1500 V/mV

= 25°C 400 800 µV

A

≤ 70°C ● 950 µV

0°C ≤ T

A

= 18V (Note 3) ● 1 µA

V

CM

= 18V (Note 3) ● 612 µA

V

CM

SHDN or V

Common Mode, V Common Mode, V

CM

= 3V, 0°C ≤ TA ≤ 70°C ● 133 V/mV

V

S

VS = 5V, VO = 500mV to 4.5V, RL = 10k 400 1500 V/mV

= 5V, 0°C ≤ TA ≤ 70°C ● 250 V/mV

V

S

= 0V, VCM = 0V to 18V 0.1 nA

S

P-P

= 0V to (V

CM

= 0V to 18V 1.5 3 MΩ

CM

= 0V to 18V (Note 6) ● 68 80 dB

– 1V) 5 GΩ

CC

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 = V

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

OL

V

OH

I

SC

I

S

I

SHDN

V

L

V

H

t

ON

t

OFF

GBW Gain Bandwidth Product f = 5kHz 110 200 kHz

SR Slew Rate AV = –1, R

t

S

THD Distortion VS = 3V, VO = 2V

FPBW Full-Power Bandwidth (Note 9) V

Output Voltage Swing LOW No Load ● 38 mV

Output Voltage Swing HIGH VS = 3V, No Load ● 2.91 2.94 V

Short-Circuit Current (Note 2) VS = 3V, Short to GND 5 10 mA

Minimum Supply Voltage ● 2.5 2.7 V

Reverse Supply Voltage I

Supply Current 40 55 µA

(Note 4)

Supply Current, SHDN V

Shutdown Pin Current V

Shutdown Output Leakage Current V

Maximum Shutdown Pin Current V Shutdown Pin Input Low Voltage (Note 8) ● 0.3 V Shutdown Pin Input High Voltage (Note 8) ● 2V

Turn-On Time V

Turn-Off Time V

(Note 3) 0°C ≤ T

(Note 5) 0°C ≤ T

Settling Time V

= half supply, for the 6-lead part V

OUT

= 5mA ● 200 500 mV

I

SINK

V

= 5V, I

S

V

= 3V, I

S

= 10mA ● 400 800 mV

SINK

= 5mA ● 2.6 2.8 V

SOURCE

VS = 5V, No Load ● 4.91 4.94 V

= 5V, I

V

S

= 3V, Short to V

V

S

= 10mA ● 4.5 4.74 V

SOURCE

CC

VS = 5V, Short to GND 15 30 mA V

= 5V, Short to V

S

= –100µA ● 18 V

S

= 2V, No Load (Note 8) ● 515 µA

PIN5

= 0.3V, No load (Note 8) ● 0.5 nA

PIN5

V

= 2V, No Load (Note 8) ● 28 µA

PIN5

= 5V, No Load (Note 8) ● 5 µA

V

PIN5

= 2V, No Load (Note 8) ● 0.05 1 µA

PIN5

= 18V, No Load (Note 8) ● 10 30 µA

PIN5

= 5V to 0V, R

PIN5

= 0V to 5V, R

PIN5

≤ 70°C ● 100 kHz

A

≤ 70°C ● 0.031 V/µs

A

= 5V, ∆V

S

= 2V

OUT

P–P

CC

= 10k (Note 8) 100 µs

L

= 10k (Note 8) 6 µs

L

= ∞ 0.035 0.07 V/µs

L

= 2V to 0.1%, A

OUT

, AV = 1, RL = 10k, f =1kHz 0.003 %

P–P

= 0V, pulse power tested unless otherwise specified.

PIN5

15 30 mA

20 40 mA

● 60 µA

= –1 45 µs

V

11 kHz

V

= ±5V, V

S

V

OS

I

OS

I

B

e

n

i

n

= 0V,V

CM

= 0V, for the 6-lead part V

OUT

Input Offset Voltage T

SHDN

= 25°C 500 900 µV

A

≤ 70°C ● 1050 µV

0°C ≤ T

A

= V

–

Input Offset Voltage Drift (Note 7) 0°C ≤ TA ≤ 70°C ● 25µV/°C Input Offset Current ● 0.7 2 nA Input Bias Current ● 815 nA Input Bias Current Drift 0°C ≤ TA ≤ 70°C ● 0.01 nA/°C Input Noise Voltage 0.1Hz to 10Hz 1 µV

P-P

Input Noise Voltage Density f = 1kHz 50 nV/√Hz 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. V

= ±5V, V

S

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

R

IN

C

IN

CMRR Common Mode Rejection Ratio VCM = –5V to 13V ● 68 80 dB

A

VOL

V

OL

V

OH

I

SC

PSRR Power Supply Rejection Ratio V

I

S

I

SHDN

V

L

V

H

t

ON

t

OFF

GBW Gain Bandwidth Product f = 5kHz 120 225 kHz

SR Slew Rate AV = –1, R

t

S

FPBW Full-Power Bandwidth (Note 9) V

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: V V

= ±5V or VS = ±9V tests.

S

Note 4: V V

= ±5V or VS = ±9V tests.

S

Note 5: Guaranteed by correlation to slew rate at V V

= 3V and V

S

= 0V,V

CM

= 0V, for the 6-lead part V

OUT

= V–, unless otherwise specified.

SHDN

Input Resistance Differential ● 3.4 6.5 MΩ

Common Mode, V

= –5V to 13V ● 1.5 3 MΩ

CM

Input Capacitance 5pF Input Voltage Range ● –5 13 V

Large-Signal Voltage Gain V

= ±4V, R

O

0°C ≤ T

= 10k 55 150 V/mV

L

≤ 70°C ● 40 V/mV

A

Output Voltage Swing LOW No Load ● –4.997 –4.992 V

I

= 5mA ● –4.8 –4.5 V

SINK

= 10mA ● –4.6 –4.2 V

I

SINK

Output Voltage Swing HIGH No Load ● 4.91 4.94 V

= 5mA ● 4.6 4.8 V

I

SOURCE

I

= 10mA ● 4.5 4.74 V

SOURCE

Short-Circuit Current (Note 2) Short to GND 18 30 mA

0°C ≤ T

≤ 70°C ● 15 mA

A

= ±1.5V to ±9V ● 90 100 dB

S

Supply Current 45 60 µA

● 65 µA

Supply Current, SHDN V

Shutdown Pin Current V

Maximum Shutdown Pin Current V

Shutdown Output Leakage Current V

Shutdown Pin Input Low Voltage V

Shutdown Pin Input High Voltage V

Turn-On Time V

Turn-Off Time V

Settling Time ∆V

= –3V, V

PIN5

= –4.7V, V

PIN5

= –3V, V

V

PIN5

= 9V, V

PIN5

= –7V, V

PIN5

= ±5V (Note 8) ● –4.7 V

S

= ±5V (Note 8) ● –3 V

S

= 0V to –5V, R

PIN5

= –5V to 0V, R

PIN5

0°C ≤ T

= 4V to 0.1%, A

OUT

= 8V

OUT

= ±5V, No Load (Note 8) ● 620 µA

S

= ±5V, No load (Note 8) ● 0.5 nA

S

= ±5V, No Load (Note 8) ● 28 µA

S

= ±9V (Note 8) ● 10 30 µA

S

= ±9V, No Load (Note 8) ● 0.05 1 µA

S

= 10k (Note 8) ● 100 µs

L

= 10k (Note 8) ● 6 µs

L

≤ 70°C ● 110 kHz

A

= ∞, VO = ±4V, Measured at VO = ±2V 0.0375 0.075 V/µs

L

≤ 70°C ● 0.033 V/µs

A

= 1 50 µs

V

P–P

3kHz

Note 6: This specification implies a typical input offset voltage of 1.8mV at V

= 18V and a maximum input offset voltage of 7.2mV at VCM = 18V.

CM

Note 7: This parameter is not 100% tested. Note 8: Specifications apply to 6-lead SOT-23 with shutdown.

= 5V limits are guaranteed by correlation to VS = 3V and

S

= 3V limits are guaranteed by correlation to VS = 5V and

S

Note 9: Full-power bandwidth is calculated for the slew rate.

FPBW = SR/2πV

.

P

Note 10: The LT1782 is guaranteed functional over the operating

temperature range –40°C to 85°C.

= ±5V, and GBW at

= ±5V tests.

S

4

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Supply Current vs Supply Voltage

50

T

= 125°C

45

40

35

30

SUPPLY CURRENT (µA)

25

20

2

A

T

= 25°C

A

T

= –55°C

A

6 10 144 8 12 16 18

SUPPLY VOLTAGE (V)

1782 G01

Minimum Supply Voltage

400

300

200

100

0

T

= 125°C

A

0

1 2 3 4 5

TOTAL SUPPLY VOLTAGE (V)

INPUT OFFSET VOLTAGE CHANGE (µV)

–100

–200

–300

–400

T

= –55°C

A

T

= 25°C

A

1782 G02

Output Voltage vs Large Input Voltage

5

VS = 5V, 0V

4

3

(V)

OUT

V

2

V

IN

1

0

–8 6 8 10 12 14 16 18

–10

–6 –4 0 2–2 4

VIN (V)

LT1782

5V

+

–

1782 G02a

Input Bias Current vs Common Mode Voltage

6000

VS = 5V, 0V

5000

4000

3000

2000

1000

40

30

20

INPUT BIAS CURRENT (nA)

10

0

–10

4.2 4.4 4.6 4.8 5 5.2 5.4 15 16 18

3.8 4

T

= 125°C

A

COMMON MODE VOLTAGE (V)

Output Saturation Voltage vs Input Overdrive

100

OUTPUT HIGH

10

OUTPUT LOW

V

= ±2.5V

OUTPUT SATURATION VOLTAGE (mV)

S

NO LOAD

1

0

10 20 30 40 50 60

INPUT OVERDRIVE (mV)

T

= –55°C

A

T

A

= 25°C

1782 G06

1782 G03

Output Saturation Voltage vs Load Current (Output High)

1

V

= ±2.5V

S

V

= 30mV

OD

T

= 125°C

A

0.1 T

= 25°C

A

OUTPUT SATURATION VOLTAGE (V)

0.01

1µ

SOURCING LOAD CURRENT (A)

100µ10µ 1m 10m

T

A

Output Short-Circuit Current vs Temperature

40

V

= ±5V

S

35

30

SOURCING CURRENT

25

OUTPUT CURRENT (mA)

20

15

–50 –25 0 25 50 75 100 125

TEMPERATURE (°C)

SINKING CURRENT

= –55°C

1782 G04

1782 G06a

Output Saturation Voltage vs Load Current (Output Low)

1

V

= ±2.5V

S

V

= 30mV

OD

T

= 125°C

0.1

T

= 25°C

A

0.01

OUTPUT SATURATION VOLTAGE (V)

0.001

1µ 1µ 1m 10m

10µ

SINKING LOAD CURRENT (A)

A

0.1Hz to 10Hz Noise Voltage

V

= ±2.5V

S

NOISE VOLTAGE (400nV/DIV)

012345678910

TIME (sec)

T

= –55°C

A

1782 G05

1782 G07

5

LT1782

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Noise Voltage Density vs Frequency

80

70

60

50

40

30

INPUT NOISE VOLTAGE DENSITY (nV/√Hz)

20

1 100 1k 10k

10

FREQUENCY (Hz)

Gain Bandwidth Product vs Temperature

230

f = 5kHz

= ±2.5V

V

S

220

210

200

190

GAIN BANDWIDTH (kHz)

180

170

–50 –25 0 25 50 75 100 125

TEMPERATURE (°C)

1782 G08

1782 G11

Input Noise Current vs Frequency

0.40

0.35

0.30

0.25

0.20

0.15

0.10

0.05

INPUT NOISE CURRENT DENSITY (pA/√Hz)

0

1 100 1k 10k

10

FREQUENCY (Hz)

Slew Rate vs Temperature

0.11

V

= ±2.5V

S

0.10

0.09

0.08

0.07

SLEW RATE (V/µs)

0.06

0.05

0.04 –50 –25 0 25 50 75 100 125

RISING

FALLING

TEMPERATURE (°C)

V

= ±2.5V

S

1782 G09

1782 G12

Gain and Phase Shift vs Frequency

70

60

50

40

30

20

GAIN (dB)

10

0

–10

–20

–30

1k

PHASE

GAIN

10k 100k 1M

FREQUENCY (Hz)

Gain Bandwidth Product and Phase Margin vs Supply Voltage

PHASE MARGIN

240

220

200

AV = –1

180

R f = 5kHz

160

GAIN BAINDWIDTH PRODUCT (kHz)

0

GAIN BANDWIDTH PRODUCT

= RG = 10k

F

2 4 6 8 10 12 14 16 18

TOTAL SUPPLY VOLTAGE (V)

V

= ±2.5V

S

1782 G10

1782 G13

100

80

60

PHASE SHIFT (DEG)

40

20

0

–20

–40

–60

–80

–100

PHASE MARGIN (DEG)

60

55

50

Gain Bandwidth Product and Phase Margin vs Load Resistance PSRR vs Frequency

PHASE MARGIN

V

= ±2.5V

S

= –1

A

V

250

200

150

100

GAIN BANDWIDTH PRODUCT (kHz)

= RG = 10k

R

F

f = 5kHz

GAIN BANDWIDTH PRODUCT

50

1k

10k 100k

LOAD RESISTANCE (Ω)

PHASE MARGIN (DEG)

70

60

50

1782 G14

90

V

= ±2.5V

S

80

70

60

50

40

30

20

10

NEGATIVE SUPPLY

0

POWER SUPPLY REJECTION RATIO (dB)

–10

1k

6

POSITIVE SUPPLY

10k 100k 1M

FREQUENCY (Hz)

1782 G15

CMRR vs Frequency

110

100

90

80

70

60

50

40

COMMON MODE REJECTION RATIO (dB)

30

1k

10k 100k

FREQUENCY (Hz)

V

= ±2.5V

S

1782 G16

UW

TYPICAL PERFOR A CE CHARACTERISTICS

LT1782

Output Impedance vs Frequency

10k

V

= ±2.5V

S

AV = 100

1k

100

OUTPUT IMPEDANCE (Ω)

0.1

AV = 10

10

AV = 1

1

100

10k1k 100k 1M

FREQUENCY (Hz)

Capacitive Load Handling Overshoot vs Capacitive Load

40

VS = 5V, 0V

35

30

25

20

15

OVERSHOOT (%)

10

= 2.5V

V

CM

AV = 1

AV = 5

5

0

10

100 1000 10000

CAPACITIVE LOAD (pF)

AV = 10

1782 G17

1782 G19

Disabled Output Impedance vs Frequency (Note 8)

1M

V

= ±2.5V

S

(SHUTDOWN) = 2.5V

V

PIN5

100k

10k

1k

OUTPUT IMPEDANCE (Ω)

100

1k 10k 100k 1M

FREQUENCY (Hz)

Undistorted Output Swing vs Frequency

12

V

= ±5V

10

)

P-P

8

6

4

OUTPUT SWING (V

2

0

100 1k 10k 100k

S

V

= ±1.5V

S

FREQUENCY (Hz)

DISTORTION ≤ 1%

Settling Time to 0.1% vs Output Step

4

3

AV = 1 AV = –1

2

1

V

= ±5V

0

S

–1

OUTPUT STEP (V)

1782 G17a

–2

–3

–4

25 30 35 40 50 60 70 80

AV = 1 AV = –1

SETTLING TIME (µs)

1782 G18

Total Harmonic Distortion + Noise vs Frequency

1

= 1

A

V

THD + NOISE (%)

1782 G20

VS = 3V, 0V V

= 2V

OUT

P-P

VCM = 1.2V R

= 10k

L

0.1

0.010

0.001

AV = –1 R

= RG = 100k

F

AV = 1

10 1k 10k

100

FREQUENCY (Hz)

1782 G21

Total Harmonic Distortion + Noise vs Load Resistance

10

VS = 3V TOTAL

= 1

A

V

= 2V

V

1

0.1

THD + NOISE (%)

0.01

0.001 100 100k

AT 1kHz

IN

P-P

V

= ±1.5V

S

= ±1V

V

IN

VS = 3V, 0V

= 0.5V TO 2.5V

V

IN

VS = 3V, 0V

= 0.2V TO 2.2V

V

IN

1k 10k

LOAD RESISTANCE TO GROUND (Ω)

1782 G22

Total Harmonic Distortion + Noise vs Output Voltage Amplitude

10

f = 1kHz, RL = 10k

= 0V

AV = –1, RF = RG = 100k

= ±1.5V

V

S

= 0V

V

CM

AV = –1, RF = RG = 100k

= 3V, 0V

V

S

= 1.5V

V

CM

)

P-P

1782 G23

AV = 1

1

0.1

THD + NOISE (%)

0.01

0.001

= ±1.5V

V

S

V

CM

AV = 1

= 3V. 0V

V

S

= 1.5V

V

CM

0123

OUTPUT VOLTAGE AMPLITUDE (V

Open-Loop Gain

V

= ±5V

S

RL = 10k

RL = 50k

RL = 2k

INPUT OFFSET VOLTAGE CHANGE (50µV/DIV)

–6

–5 –4 –3 –2 –1 0 1 2 3 456

OUTPUT VOLTAGE (V)

1782 G24

7

LT1782

UW

TYPICAL PERFOR A CE CHARACTERISTICS

Supply Current vs Shutdown Voltage

50

T

= 125°C

A

40

T

= 25°C

A

30

20

SUPPLY CURRENT (µA)

10

0

0 0.5 1 1.5 2 2.5

SHUTDOWN PIN VOLTAGE (V)

T

= –55°C

A

VS = 5V, 0V

1782 G25

Large-Signal Response

V

= ±5V 1782 G26

S

AV = 1 CL = 15pF

Small-Signal Response

V

= ±5V 1782 G27

S

AV = 1 CL = 15pF

U

WUU

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.

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 volt-

age 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,

8

LT1782

U

WUU

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 condi-

tions. 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– ≤ V

OUT

≤ 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.”

SI PLIFIED

SHDN

J1

Q26

+

2µA

Q23 Q24Q25

WW

SCHE ATIC

Q1

R1 30k

Q4

–IN

+IN

Q5

R2 6k

R3 6k

Q6

+

Q22

Q21

1782 SS

V

OUT

V

–

Q2

D1

Q7

Q8

Q9

D5

D4

Q10

Q11 Q12

Q13 Q14

R4 40k

R5 40k

Q15

Q3

D3

Q19

Q17 Q20

Q16 Q18

9

LT1782

PACKAGE DESCRIPTIO

U

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)

1.90

2.60 – 3.00

(0.102 – 0.118)

1.50 – 1.75

(0.059 – 0.069)

0.35 – 0.55

(0.014 – 0.022)

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)

0.09 – 0.20

(0.004 – 0.008)

(NOTE 2)

(0.074)

REF

0.00 – 0.15

(0.00 – 0.006)

0.35 – 0.50

(0.014 – 0.020)

FIVE PLACES (NOTE 2)

0.95

(0.037)

REF

0.90 – 1.45

(0.035 – 0.057)

0.90 – 1.30

(0.035 – 0.051)

S5 SOT-23 0599

10

PACKAGE DESCRIPTIO

LT1782

U

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

2.6 – 3.0

(0.110 – 0.118)

1.50 – 1.75

(0.059 – 0.069)

0.35 – 0.55

(0.014 – 0.022)

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)

0.09 – 0.20

(0.004 – 0.008)

(NOTE 2)

(0.074)

REF

0.00 – 0.15

(0.00 – 0.006)

0.35 – 0.50

(0.014 – 0.020)

SIX PLACES (NOTE 2)

0.95

(0.037)

REF

0.90 – 1.45

(0.035 – 0.057)

0.90 – 1.30

(0.035 – 0.051)

S6 SOT-23 0898

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

TYPICAL APPLICATIO S

U

Current Source

V

CC

LT1634-1.25

R1

+

I

OUT

2N3906

1.25V

=

R1

1782 TA02

LT1782

–

Protected Fault Conditions

–18V

+

V

LT1782

+

24V

REVERSE BATTERY INPUT OVERVOLTAGE

5V

5VOK! OK!

LT1782

5VOK! OK!

+

18V

INPUT DIFFERENTIAL VOLTAGE INPUT BELOW GROUND

LT1782 LT1782

10V

+

1782 TA03

RELATED PARTS

PART NUMBER DESCRIPTION COMMENTS

LT1783 Micropower Over-The-Top SOT-23 Rail-to-Rail Input SOT-23 Package, Micropower 210µA per Amplifier, Rail-to-Rail Input

and Output Op Amp and Output , 1.25MHz GBW

LT1490/LT1491 Dual/Quad Over-The-Top Micropower Rail-to-Rail Input Single Supply Input Range: –0.4V to 44V, Micropower 50µA per

and Output Op Amps Amplifier, Rail-to-Rail Input and Output , 200kHz GBW

LT1636 Single Over-The-Top Micropower Rail-to-Rail Input 55µA Supply Current, V

and Output Op Amp V

, MSOP Package, Shutdown Function

CC

LT1638/LT1639 Dual/Quad, 1.2MHz, 0.4V/µs, Over-The-Top Micropower 170µA Supply Current, Single Supply Input Range: –0.4V to 44V,

Rail-to-Rail Input and Output Op Amps Rail-to-Rail Input and Output

Linear Technology Corporation

12

1630 McCarthy Blvd., Milpitas, CA 95035-7417

(408) 432-1900 ● FAX: (408) 434-0507

●

www.linear-tech.com

Extends 44V Above VEE, Independent of

CM

1782f LT/TP 0400 4K • PRINTED IN USA

 LINEAR TECHNOLOGY CORPORATION 1999