INA145 [BB]

Programmable Gain DIFFERENCE AMPLIFIER; 可编程增益差动放大器器


型号：	INA145
厂家：	BURR-BROWN CORPORATION
描述：	Programmable Gain DIFFERENCE AMPLIFIER 可编程增益差动放大器器放大器
文件：	总11页 (文件大小：129K)
中文：	中文翻译
下载：	下载PDF数据表文档文件

INA145

For most current data sheet and other product

information, visit www.burr-brown.com

Programmable Gain

DIFFERENCE AMPLIFIER

FEATURES

DESCRIPTION

● DIFFERENTIAL GAIN = 1V/V TO 1000V/V:

The INA145 is a precision, unity-gain difference

amplifier consisting of a precision op amp and on-

chip precision resistor network. Two external resistors

set the gain from 1V/V to 1000V/V. The input com-

mon-mode voltage range extends beyond the positive

and negative rails.

Set with External Resistors

● LOW QUIESCENT CURRENT: 570µA

● WIDE SUPPLY RANGE:

Single Supply: 4.5V to 36V

Dual Supplies: ±2.25V to ±18V

On-chip precision resistors are laser-trimmed to achieve

accurate gain and high common-mode rejection. Ex-

cellent TCR tracking of these resistors assures contin-

ued high precision over temperature.

● HIGH COMMON-MODE VOLTAGE:

+8V at V_S= +5V

±28V at V_S= ±15V

● LOW GAIN ERROR: 0.01%

● HIGH CMR: 86dB

The INA145 is available in the SO-8 surface-mount

package specified for the extended industrial tempera-

ture range, –40°C to +85°C.

● SO-8 PACKAGE

APPLICATIONS

● CURRENT SHUNT MEASUREMENTS

● SENSOR AMPLIFIER

●

DIFFERENTIAL LINE RECEIVER

● BATTERY POWERED SYSTEMS

R_G1

R_G2

V+

R_G

R₁

R₂

40kΩ

V_IN^–

R₅

10kΩ

(1%)

V_O

G = 1

R₃

_O= (V_I⁺_N– V_I^–_N)(1 + R_G2/R_G1

)

R₄

40kΩ

V_IN⁺

INA145

V–

Ref

V₀₁

International Airport Industrial Park • Mailing Address: PO Box 11400, Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706 • Tel: (520) 746-1111

Twx: 910-952-1111 • Internet: http://www.burr-brown.com/ • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

PDS-1567B

Printed in U.S.A. March, 2000

INA145

SPECIFICATIONS: V_S= ±2.25V to ±18V

Boldface limits apply over the specified temperature range, T_A= –40°C to +85°C

At T_A= +25°C, G = 1, R_L= 10kΩ connected to ground and ref pin connected to ground unless otherwise noted.

INA145UA

PARAMETER

CONDITION

MIN

TYP

MAX

UNITS

OFFSET VOLTAGE, V_O

Input Offset Voltage

vs Temperature

vs Power Supply

vs Time

RTI^{(1, 2)}

V_CM= V_O= 0V

V_OS

∆V_OS/∆T

PSRR

±0.2

±1

See Typical Curve

V_S= ±1.35V to ±18V

±20

±0.3

±0.4

±60

µV/V

µV/mo

Offset Voltage, V₀₁

RTI^{(1, 2)}

INPUT VOLTAGE RANGE

Common-Mode Voltage Range

Common-Mode Rejection

Over Temperature

V_CM

CMRR

(V_IN+) – (V_IN–) = 0V, V_O= 0V

V_CM= 2(V–) to 2(V+) – 2V, R_S= 0Ω

V_S= ±15V

2(V–)

2(V+) –2

INPUT BIAS CURRENT⁽²⁾

Bias Current

Offset Current

V_CM= V_S/2

I_B

I_OS

±50

±5

INPUT IMPEDANCE

Differential (non-inverting input)

Differential (inverting input)

Common-Mode

kΩ

NOISE

RTI^{(1, 3)}

Voltage Noise, f = 0.1Hz to 10Hz

Voltage Noise Density, f = 1kHz

µVp-p

nV/√Hz

e_n

GAIN

G = 1 to 1000

Gain Equation

Initial⁽¹⁾

Gain Error

vs Temperature

G = 1 + R_G2/R_G1

V/V

ppm/°C

% of FS

±0.01

±2

±0.01

±2

R_L= 100kΩ, V_O= (V–)+0.15 to (V+)–1, G = 1

R_L= 100kΩ, V_O= (V–)+0.25 to (V+)–1, G = 1

R_L= 10kΩ, V_O= (V–)+0.3 to (V+)–1.25, G = 1

R_L= 10kΩ, V_O= (V–)+0.5 to (V+)–1.25, G = 1

R_L= 10kΩ, V_O= (V–)+0.3 to (V+)–1.25, G = 1

±0.1

±10

±0.1

±10

±0.005

vs Temperature

Nonlinearity

±0.0002

FREQUENCY RESPONSE

Small Signal Bandwidth

G = 1

G = 10

500

0.45

kHz

V/µs

µs

Slew Rate

Settling Time, 0.1%

0.01%

G = 1, 10V Step

µs

Overload Recovery

50% Input Overload

µs

OUTPUT, V_O

Voltage Output

Over Temperature

R_L= 100kΩ, G = 1

R_L= 10kΩ, G = 1

Continuous to Common

Stable Operation

(V–) + 0.15

(V–) + 0.25

(V–) + 0.3

(V–) + 0.5

(V+) – 1

(V+) – 1.25

Over Temperature

Short-Circuit Current

Capacitive Load

±15

1000

POWER SUPPLY

Specified Voltage Range, Dual Supplies

Operating Voltage Range

Quiescent Current

±2.25

±1.35

±18

±700

±800

µA

V_IN= 0, I_O= 0

±570

Over Temperature

TEMPERATURE RANGE

Specified Range

Operating Range

Storage Range

–40

–55

+85

+125

°C

Thermal Resistance

θ_JA

150

°C/W

NOTES: (1) Referred to input pins (V_IN+ and V_IN–), Gain = 1V/V. Specified with 10kΩ in feedback of A2. (2) Input offset voltage specification includes effects of amplifier’s

input bias and offset currents. (3) Includes effects of input bias current noise and thermal noise contribution of resistor network.

The information provided herein is believed to be reliable; however, BURR-BROWN assumes no responsibility for inaccuracies or omissions. BURR-BROWN assumes

no responsibility for the use of this information, and all use of such information shall be entirely at the user’s own risk. Prices and specifications are subject to change

without notice. No patent rights or licenses to any of the circuits described herein are implied or granted to any third party. BURR-BROWN does not authorize or warrant

any BURR-BROWN product for use in life support devices and/or systems.

INA145

SPECIFICATIONS: V_S= +5V Single Supply

Boldface limits apply over the specified temperature range, T_A= –40°C to +85°C

At T_A= +25°C, G = 1, R_L= 10kΩ connected to ground and ref pin connected to 2.5V unless otherwise noted.

INA145UA

PARAMETER

CONDITION

MIN

TYP

MAX

UNITS

OFFSET VOLTAGE, V_O

Input Offset Voltage

vs Temperature

vs Power Supply Rejection Ratio

vs Time

RTI^{(1, 2)}

V_CM= V_O= 2.5V

V_OS

∆V_OS/∆T

PSRR

±0.35

See Typical Curve

±1

V_S= ±1.35V to ±18V

±20

±0.3

±0.55

±60

µV/°C

µV/mo

Offset Voltage, V₀₁

RTI^{(1, 2)}

INPUT VOLTAGE RANGE

Common-Mode Voltage Range⁽³⁾

Common-Mode Rejection Ratio

Over Temperature

V_CM

CMRR

V_IN+ – V_IN– = 0V, V_O= 2.5V

V_CM= –2.5V to +5.5V, R_S= 0Ω

–2.5

5.5

INPUT BIAS CURRENT⁽²⁾

Bias Current

Offset Current

I_B

I_OS

±50

±5

INPUT IMPEDANCE

Differential (non-inverting input)

Differential (inverting input)

Common-Mode

kΩ

NOISE

RTI^{(1, 4)}

Voltage Noise, f = 0.1Hz to 10Hz

Voltage Noise Density, f = 1kHz

µVp-p

nV/√Hz

e_n

GAIN

Gain Equation

Initial⁽¹⁾

G = 1 to 1000

G = 1 + R_G2/R_G1

V/V

Gain Error

vs Temperature

R_L= 100kΩ, V_O= 0.15V to 4V, G = 1

R_L= 100kΩ, V_O= 0.25V to 4V, G = 1

R_L= 10kΩ, V_O= 0.3V to 3.75V, G = 1

R_L= 10kΩ, V_O= 0.5V to 3.75V, G = 1

R_L= 10kΩ, V_O= +0.3 to +3.75, G = 1

±0.01

±2

±0.01

±2

±0.001

±0.1

±10

±0.1

±10

±0.005

ppm/°C

% of FS

vs Temperature

Nonlinearity

FREQUENCY RESPONSE

Small Signal Bandwidth

G = 0.1

G = 1

500

0.45

kHz

V/µs

µs

Slew Rate

Settling Time, 0.1%

0.01%

G = 1, 10V Step

µs

Overload Recovery

50% Input Overload

µs

OUTPUT, V_O

Voltage Output

Over Temperature

R_L= 100kΩ, G = 1

R_L= 10kΩ, G = 1

Continuous to Common

Stable Operation

0.15

0.25

0.3

3.75

Over Temperature

Short-Circuit Current

Capacitive Load

0.5

±15

1000

POWER SUPPLY

Specified Voltage Range, Single Supply

Operating Voltage Range

Quiescent Current

+4.5

+2.7

+36

700

800

µA

V_IN= 0, I_O= 0

550

Over Temperature

TEMPERATURE RANGE

Specified Range

Operating Range

Storage Range

–40

–55

+85

+125

°C

Thermal Resistance

θ_JA

150

°C/W

NOTES: (1) Referred to input pins (V_IN+ and V_IN–), Gain = 1V/V. Specified with 10kΩ in feedback of A2. (2) Input offset voltage specification includes effects of

amplifier’s input bias and offset currents. (3) Common-mode voltage range with single supply is 2(V+) – 2V – V_REFto –V_REF. (4) Includes effects of input current

noise and thermal noise contribution of resistor network.

INA145

AMPLIFIER A1, A2 PERFORMANCE

Boldface limits apply over the specified temperature range, T_A= –40°C to +85°C

At T_A= +25°C, G = 1, R_L= 10kΩ connected to ground and ref pin connected to ground unless otherwise noted.

INA145UA

PARAMETER

CONDITION

MIN

TYP

MAX

UNITS

OFFSET VOLTAGE, V_O

Input Offset Voltage

vs Temperature

RTI^{(1, 2)}

V_S= ±15V, V_CM= V_O= 0V

V_OS

∆V_OS/∆T

±0.5

±1

µV/°C

INPUT VOLTAGE RANGE

Common-Mode Voltage Range

Common-Mode Rejection Ratio

V_CM

CMRR

V_IN+ – V_IN– = 0V, V_O= 0V

V_CM= (V–) to (V+) –1

(V–) to (V+) –1

OPEN-LOOP GAIN

Open Loop Gain

A_OL

110

INPUT BIAS CURRENT⁽²⁾

Bias Current

Offset Current

I_B

I_OS

±50

±5

RESISTOR AT A1 OUTPUT, V_O1

Initial

Error

±0.2

±50

kΩ

ppm/°C

Temperature Drift Coefficient

PIN CONFIGURATION

ELECTROSTATIC

DISCHARGE SENSITIVITY

Top View

SO-8

This integrated circuit can be damaged by ESD. Burr-Brown

recommends that all integrated circuits be handled with

appropriate precautions. Failure to observe proper handling

and installation procedures can cause damage.

Ref

V_I^–_N

V_I⁺_N

V–

V_O1

V+

V_O

R_G

ESD damage can range from subtle performance degradation

to complete device failure. Precision integrated circuits may

be more susceptible to damage because very small parametric

changes could cause the device not to meet its published

specifications.

ABSOLUTE MAXIMUM RATINGS⁽¹⁾

Supply Voltage, V+ to V– .................................................................... 36V

Signal Input Terminals, Voltage ........................................................ ±80V

Current ....................................................... ±1mA

Output Short Circuit (to ground).............................................. Continuous

Operating Temperature .................................................. –55°C to +125°C

Storage Temperature .....................................................–55°C to +150°C

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

Lead Temperature (soldering, 10s)............................................... +240°C

NOTE: (1) Stresses above these ratings may cause permanent damage.

Exposure to absolute maximum conditions for extended periods may degrade

device reliability.

PACKAGE/ORDERING INFORMATION

PACKAGE

SPECIFIED

DRAWING

NUMBER

TEMPERATURE

RANGE

PACKAGE

MARKING

ORDERING

NUMBER⁽¹⁾

TRANSPORT

MEDIA

PRODUCT

PACKAGE

INA145UA

SO-8

182

–40°C to +85°C

INA145UA

Rails

INA145UA/2K5

Tape and Reel

NOTE: (1) Models with a slash (/) are available only in Tape and Reel in the quantities indicated (e.g., /2K5 indicates 2500 devices per reel). Ordering 2500 pieces

of “INA145UA/2K5” will get a single 2500-piece Tape and Reel.

INA145

TYPICAL PERFORMANCE CURVES

At T_A= +25°C, V_S= ±15V, G = 1, R_L= 10kΩ connected to ground and Ref pin connected to ground, unless otherwise noted.

GAIN vs FREQUENCY

G = 100

GAIN vs FREQUENCY

V_S= ±15V

_L= 1000pF

V_S= ±15V

C_L= 200pF 10kΩ

G = 100

G = 10

G = 1

–20

100

10K

100K

10M

100k

100

10K

100K

10M

Frequency (Hz)

POWER SUPPLY REJECTION vs FREQUENCY

COMMON-MODE REJECTION vs FREQUENCY

100

PSR+

(V_S= ±15V)

PSR+

(V_S= +5V)

PSR–

(V_S= ±15V)

100

10k

100k

100

10k

100k

Frequency (Hz)

0.1Hz to 10Hz VOLTAGE NOISE (RTI)

INPUT VOLTAGE NOISE DENSITY

100

G = 1

G = 100

G = 10

0.1

100

10k

500ms/div

Frequency (Hz)

INA145

TYPICAL PERFORMANCE CURVES (Cont.)

At T_A= +25°C, V_S= ±15V, G = 1, R_L= 10kΩ connected to ground and Ref pin connected to ground, unless otherwise noted.

QUIESCENT CURRENT AND

SHORT-CIRCUIT CURRENT vs TEMPERATURE

SLEW RATE vs TEMPERATURE

670

650

630

610

590

570

550

530

510

490

470

0.6

0.55

0.5

G = 1

I_SC

0.45

0.4

I_Q

0.35

0.3

0.25

0.2

–60 –40 –20

60 80 100

140

120

–60 –40 –20

60 80 100

140

120

Temperature (°C)

GAIN AND PHASE vs FREQUENCY

Op Amp A1 and A2

SETTLING TIME vs LOAD CAPACITANCE

110

100

160

140

120

100

R_L= 10kΩ || 200pF

G = 1

0.01%

G = 10

0.01%

–90

R_L= 1nF

G = 10

0.1%

G = 1

0.1%

–135

–180

–10

100

Frequency (Hz)

10k

100k

100

Load Capacitance (nF)

MAXIMUM OUTPUT VOLTAGE SWING

vs OUTPUT CURRENT

OFFSET VOLTAGE

PRODUCTION DISTRIBUTION

Typical Production

Distribution of

Packaged Units.

V_S= ±2.25V

–25°C

+25°C

+125°C

+85°C

–55°C

+125°C

–5

–10

–15

+25°C

–25°C

+85°C

Output Current (mA)

Offset Voltage, RTI (mV)

INA145

TYPICAL PERFORMANCE CURVES (Cont.)

At T_A= +25°C, V_S= ±15V, G = 1, R_L= 10kΩ connected to ground and Ref pin connected to ground, unless otherwise noted.

OFFSET VOLTAGE DRIFT

OFFSET VOLTAGE

PRODUCTION DISTRIBUTION

Typical Production

Distribution of

Packaged Devices

V_S= ±15V

Offset Voltage Drift, RTI (µV/°C)

Offset Voltage, RTI (mV)

SMALL-SIGNAL STEP RESPONSE

(G = 1, C_L= 1000pF)

(G = 1, R_L= 10kΩ, C_L= 200pF)

5µs/div

LARGE-SIGNAL STEP RESPONSE

SMALL-SIGNAL STEP RESPONSE

(G = 10, C_L= 1000pF)

(G = 10, R_L= 10kΩ, C_L= 200pF)

50µs/div

5µs/div

INA145

SETTING THE GAIN

APPLICATION INFORMATION

The gain of the INA145 is set by using two external

resistors, R_G1and R_G2, according to the equation:

The INA145 is a programmable gain difference amplifier

consisting of a gain of 1 difference amplifier and a program-

mable-gain output buffer stage. Basic circuit connections are

shown in Figure 1. Power supply bypass capacitors should

be connected close to pins 4 and 7, as shown. The amplifier

is programmable in the range of G = 1 to G = 1000 with two

external resistors.

G = 1 + R_G2/R_G1

For a total gain of 1, A2 is connected as a buffer amplifier

with no R_G1. A feedback resistor, R_G2= 10kΩ, should be

used in the buffer connection. This provides bias current

cancellation (in combination with internal R₅) to assure

specified offset voltage performance. Commonly used val-

ues are shown in the table of Figure 1. Resistor values for

other gains should be chosen to provide a 10kΩ parallel

resistance.

The output of A1 is connected to the noninverting input of

A2 through a 10kΩ resistor which is trimmed to ±1%

absolute accuracy. The A2 input is available for applications

such as a filter or a precision current source. See application

figures for examples.

COMMON-MODE RANGE

OPERATING VOLTAGE

The input resistors of the INA145 provides an input com-

mon-mode range that extends well beyond the power supply

rails. Exact range depends on the power supply voltage and

the voltage applied to the Ref terminal (pin 1). To assure

proper operation, the voltage at the non-inverting input of

A1 (an internal node) must be within its linear operating

range. Its voltage is determined by the simple 1:1 voltage

divider between pin 3 and pin 1. This voltage must be

between V– and (V+) – 1V.

The INA145 is fully specified for supply voltages from

±2.25V to ±18V, with key parameters guaranteed over the

temperature range –40°C to +85°C. The INA145 can be

operated with single or dual supplies, with excellent perfor-

mance. Parameters that vary significantly with operating

voltage, load conditions, or temperature are shown in the

typical performance curves.

+V_S

R_G1

R_G2

0.1µF

R_B

R₁

R₂

40kΩ

V_IN^–

V_O= (V_I⁺_N– V_I^–_N)(1 + R_G2/R_G1

)

R₅

10kΩ

(1%)

V_O

STANDARD 1% RESISTORS

R₃

40kΩ

R₄

40kΩ

TOTAL GAIN A2 GAIN

R_G1

(W)

R_G2

(W)

R_B

(W)

(V/V)

V_I⁺_N

INA145

(None)

20k

10k

20k

—

9.53k

10k

12.4k

11.0k

10.5k

10.2k

499

49.9k

100k

200k

499k

100k

49.9k

100k

0.1µF

V₀₁

–V_S

100

200

500

1000

100

200

500

1000

100

FIGURE 1. Basic Circuit Connections.

INA145

OFFSET TRIM

INPUT IMPEDANCE

The INA145 is laser-trimmed for low offset voltage and

drift. Most applications require no external offset adjust-

ment. Figure 2 shows an optional circuit for trimming the

offset voltage. A voltage applied to the Ref terminal will

be summed with the output signal. This can be used to null

offset voltage. To maintain good common-mode rejection,

the source impedance of a signal applied to the Ref

terminal should be less than 10Ω and a resistor added to

the positive input terminal should be 10 times that, or

100Ω. Alternatively, the trim voltage can be buffered with

an op amp such as the OPA277.

The input impedance of the INA145 is determined by the

input resistor network and is approximately 40kΩ. The

source impedance at the two input terminals must be nearly

equal to maintain good common-mode rejection. A 5Ω

mismatch in impedance between the two inputs will cause

the typical common-mode rejection to be degraded to ap-

proximately 72dB. Figure 7 shows a common application

measuring power supply current through a shunt resistor.

The source impedance of the shunt resistor, R_S, is balanced

by an equal compensation resistor, R_C.

Source impedances greater than 300Ω are not recommended,

even if they are perfectly matched. Internal resistors are laser

trimmed for accurate ratios, not to absolute values. Adding

equal resistors greater than 300Ω can cause a mismatch in

the total resistor ratios, degrading CMR.

10kΩ

40kΩ

V_I^–_N

10kΩ

V_O

10Ω

V_I⁺_N

40kΩ

INA145

+15V

Offset Adjustment Range = ±15mV, RTI

(±1.5mV at pin 1)

V_O1

R_T

100kΩ

10Ω

NOTE: Increasing the trim resistor

_Twill decrease the trim range

–15V

FIGURE 2. Optional Offset Trim Circuit.

R_G1

10.2kΩ

R_G2

1MΩ

V+

+5V

R_S

1Ω

G = 100

I_L

V_B

10kΩ

V_O= 100 I_LR_S

Load

INA145

V+

Max V_B

+5V

+7V

12V

18V

28V

+10V

+15V

FIGURE 3. Measuring Current with Shunt Resistor.

INA145

10kΩ

Pole at

106Hz

G = 1

1500pF

R_G2

1MΩ

R_G1

10kΩ

V_I^–_N

V_O

V_I^–_N

V_I⁺_N

10kΩ

V_O

INA145

R₄

R₃

V_I⁺_N

R₃

INA145

G =

R₃+ R₄

G ≤ 1

22nF

Pole at

720Hz

FIGURE 5. Creating Gains Less Than Unity.

FIGURE 4. Noise Filtering.

R_G2

10kΩ

R₁

R₂

V_I^–_N

0V ≤ V_O≤ 5V

Alternate

Soft Clamp

10kΩ

V_O

To Pin 8

R₃

R₄

V_I⁺_N

INA145

1N4684

(3.3V)

1N914

(1)

5.0V

or Analog-to-Digital V_S

Voltage

Reference

1N914

(1)

NOTE: (1) 1/2 OPA2342 with V_Sconnected to +5V and GND.

FIGURE 6. Clamp Circuits.

INA145

R_G2

R_G1

100kΩ

11kΩ

Power

Supply

For sense resistors (R_S)

greater than 5Ω, use

G = 10

V_O

R_C

10Ω

series

compensation

resistor (R_C) for good

common-mode rejection.

Sense resistors greater

than 200Ω are not

recommended.

R_S

10Ω

INA145

Load

V_O1

FIGURE 7. Current Monitor, G = 1.

+5V

24V

8.4kΩ

Feedback

8kΩ

V_O

10kΩ

2kΩ

SHUNT

R-I Lamp/10

e.g., 0.1Ω for 1A

1V – 50mV

INA145

10MΩ

Lamp

FIGURE 8. Comparator Output with Optional Hysteresis Application to Sense Lamp Burn-Out.

R_G2

R_G1

100kΩ

11kΩ

R_G2

10kΩ

V_I^–_N

V_O

10kΩ

V_O

R₁

1MΩ

V_I⁺_N

INA145

V_I⁺_N

C₁

0.1µF

INA145

Pole at

I_OUT= (V_I⁺_N– V_I^–_N)/10kΩ

f =

= 1.6Hz

OPA277

2πR₁R_C

FIGURE 9. AC Coupling (DC Restoration).

FIGURE 10. Precision Current Source.

INA145

INA145 [BB]

相关型号：

SI9130DB

SI9135LG-T1

SI9135LG-T1-E3

SI9135_11

SI9136_11

SI9130CG-T1-E3

SI9130LG-T1-E3

SI9130_11

SI9137

SI9137DB

SI9137LG

SI9122E