INA2332

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INA2332 | Manualzz

INA3

32 INA2332

®

INA332

INA2332

SBOS216B – SEPTEMBER 2001 - REVISED OCTOBER 2006

Low-Power, Single-Supply, CMOS

INSTRUMENTATION AMPLIFIERS

FEATURES

DESIGNED FOR LOW COST

HIGH GAIN ACCURACY: G = 5, 0.07%, 2ppm/

°

C

GAIN SET WITH EXT. RESISTORS FOR > 5V/V

HIGH CMRR: 73dB DC, 50dB at 45kHz

LOW BIAS CURRENT: 0.5pA

BANDWIDTH, SLEW RATE: 2.0MHz, 5V/

µ

s

RAIL-TO-RAIL OUTPUT SWING: (V+) – 0.02V

WIDE TEMPERATURE RANGE: –55

°

C to +125

°

C

LOW QUIESCENT CURRENT: 490

µ

A max/chan

SHUTDOWN: 0.01

µ

A

MSOP-8 SINGLE AND TSSOP-14 DUAL PACKAGES

APPLICATIONS

INDUSTRIAL SENSOR AMPLIFIERS:

Bridge, RTD, Thermocouple, Position

PHYSIOLOGICAL AMPLIFIERS: ECG, EEG, EMG

A/D CONVERTER SIGNAL CONDITIONING

DIFFERENTIAL LINE RECEIVERS WITH GAIN

FIELD UTILITY METERS

PCMCIA CARDS

AUDIO AMPLIFIERS

COMMUNICATION SYSTEMS

TEST EQUIPMENT

AUTOMOTIVE INSTRUMENTATION

DESCRIPTION

The INA332 and INA2332 are rail-to-rail output, low-power

CMOS instrumentation amplifiers that offer wide range, singlesupply, and bipolar-supply operation. Using a special manufacturing flow, the INA332 family provides the lowest cost available, while still achieving low-noise amplification of differential signals with low quiescent current of 415

µ

A (dropping to 0.01

µ

A when shut down). Returning to normal operation within microseconds, this INA can be used for battery or multichannel applications.

Configured internally in a gain of 5V/V, the INA332 offers flexibility in higher gains by choosing external resistors.

R

1

40k

G = 5 + 5(R

2

/R

1

)

10k

V

REF

40k

10k

A1

A2

V

IN

V

IN

+

The INA332 rejects line noise and its harmonics because common-mode error remains low even at higher frequencies.

High bandwidth and slew rate make the INA332 ideal for directly driving sampling Analog-to-Digital (A/D) converters as well as general-purpose applications.

With high precision, low cost, and small packages, the

INA332 outperforms discrete designs.

Additionally, because they are specified for a wide temperature range of –55

°

C to +125

°

C, the INA332 family can be used in demanding environments.

R

2

R

G

INA332

A3

V

OUT

INA2332

Ch A

Ch B

V+ V– Shutdown

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

All trademarks are the property of their respective owners.

Copyright © 2001-2006, Texas Instruments Incorporated

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters.

www.ti.com

2

ABSOLUTE MAXIMUM RATINGS

(1)

Supply Voltage, V+ to V– .................................................................... 7.5V

Signal Input Terminals, Voltage

(2)

..................... (V–) – 0.5V to (V+) + 0.5V

Current

(2)

..................................................... 10mA

Output Short-Circuit

(3)

.............................................................. Continuous

Operating Temperature .................................................. –55

°

C to +125

°

C

Storage Temperature ...................................................... –65

°

C to +150

°

C

Junction Temperature .................................................................... +150

°

C

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

Exposure to absolute maximum conditions for extended periods may degrade device reliability. (2) Input terminals are diode-clamped to the power-supply rails.

Input signals that can swing more than 0.5V beyond the supply rails should be current limited to 10mA or less. (3) Short-circuit to ground, one amplifier per package.

ELECTROSTATIC

DISCHARGE SENSITIVITY

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

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.

PACKAGE/ORDERING INFORMATION

(1)

PRODUCT

Single

INA332AIDGK

"

Dual

INA2332AIPW

"

PACKAGE-LEAD

MSOP-8

"

TSSOP-14

"

PACKAGE

DESIGNATOR

DGK

"

PW

"

TEMPERATURE

RANGE

–55

°

C to +125

°

C

"

–55

°

C to +125

°

C

"

SPECIFIED

PACKAGE

MARKING

B32

"

2332A

"

ORDERING

NUMBER

INA332AIDGKT

INA332AIDGKR

INA2332AIPWT

INA2332AIPWR

TRANSPORT

MEDIA, QUANTITY

Tape and Reel, 250

Tape and Reel, 2500

Tape and Reel, 250

Tape and Reel, 2500

NOTE: (1) For the most current package and ordering information, see the Package Option Addendum at the end of this data sheet, or see the TI web site at www.ti.com.

PIN CONFIGURATION

Top View

INA2332

RG 1

V

IN

V

IN

+

2

3

V– 4

INA332

MSOP-8 (DGK)

8 Shutdown

7 V+

6 V

OUT

5 REF

RGA

V

IN

–A

V

IN

+A

V–

V

IN

+B

V

IN

–B

RGB

5

6

7

3

4

1

2

14

13

12

11

Shutdown A

V

OUT

A

REFA

V+

REFB 10

9

8

V

OUT

B

Shutdown B

Dual, TSSOP-14 (PW) www.ti.com

INA332, INA2332

SBOS216B

ELECTRICAL CHARACTERISTICS: V

S

= +2.7V TO +5.5V

BOLDFACE limits apply over the specified temperature range, T

A

= –55

At T

A

= +25

°

C, R

L

= 10k

, G = 25, and V

CM

= V

S

/2, unless otherwise noted.

°

C TO +125

°

C

CONDITION MIN

INA332AIDGK

INA2332AIPW

TYP MAX PARAMETER

INPUT

Input Offset Voltage, RTI

Over Temperature

Temperature Coefficient

vs Power Supply

Over Temperature

Long-Term Stability

Input Impedance

Input Common-Mode Range

V

OS dV

OS

/dT

PSRR

V

S

= +5V

V

S

= +2.7V to +5.5V

±

2

±

5

±

50

±

0.4

10

13

|| 3

±

8

±

9

±

250

±

260

Common-Mode Rejection

Over Temperature

CMRR

V

S

= 2.7V

V

S

= 5V

V

S

= 5V, V

CM

= 0.55V to 3.8V

V

S

= 5V, V

CM

= 0.55V to 3.8V

V

S

= 2.7V, V

CM

= 0.35V to 1.5V

0.35

0.55

60

60

73

73

114

1.5

3.8

Crosstalk, Dual

INPUT BIAS CURRENT

Bias Current

Offset Current

I

B

I

OS

NOISE, RTI

Voltage Noise: f = 10Hz f = 100Hz f = 1kHz f = 0.1Hz to 10Hz

Current Noise: f = 1kHz

GAIN

(1)

Gain Equation, Externally Set

Range of Gain

Gain Error

vs Temperature

Nonlinearity

Over Temperature

OUTPUT

Output Voltage Swing from Rail

(2)

Over Temperature

Capacitance Load Drive

Short-Circuit Current e i

N

N

I

SC

FREQUENCY RESPONSE

Bandwidth, –3dB

Slew Rate

Settling Time, 0.1%

0.01%

Overload Recovery

BW

SR t

S

POWER SUPPLY

Specified Voltage Range

Operating Voltage Range

Quiescent Current per Channel I

Q

Over Temperature

Shutdown Quiescent Current/Chan I

SD

TEMPERATURE RANGE

Specified/Operating Range

Storage Range

Thermal Resistance

θ

JA

V

CM

= V

S

/2

R

S

= 0

G > 5

G = 5

G = 25, V

S

= 5V, V

O

= 0.05 to 4.95

G

10

G = 25

V

S

= 5V, G = 25

G = 25, C

L

= 100pF, V

O

= 2V step

50% Input Overload G = 25

V

SD

> 2.5

(4)

V

SD

< 0.8

(4)

MSOP-8, TSSOP-14 Surface Mount

5

50

50

+2.7

–55

–65

±

0.5

±

0.5

2.0

5

1.7

2.5

2

280

96

46

7

0.5

G = 5 + 5(R

2

/R

1

)

±

0.07

±

2

±

0.001

±

0.002

25

See Typical Characteristics

(3)

+48/–32

+2.5 to +5.5

415

0.01

150

±

10

±

10

1000

±

0.4

±

10

±

0.010

±

0.015

+5.5

490

600

1

+125

+150

UNITS

pA pA nV/

Hz nV/

Hz nV/

Hz

µ

Vp-p fA/

Hz

V/V

%

ppm/

°

C

% of FS

% of FS

V

V

µ

A

µ

A

µ

A

MHz

V/

µ s

µ s

µ s

µ s

°

C

°

C

°

C/W

NOTES: (1) Does not include errors from external gain setting resistors.

(2) Output voltage swings are measured between the output and power-supply rails. Output swings to rail only if G

10. Output does not swing to positive rail if gain is less than 10.

(3) See typical characteristic curve, Percent Overshoot vs Load Capacitance.

(4) See typical characteristic curve,

Shutdown Voltage vs Supply Voltage.

mV

mV

µ

V/

°

C

µ

V/V

µ

V/V

µ

V/month

|| pF

V

V dB

dB

dB dB mV

mV

pF mA

INA332, INA2332

SBOS216B

www.ti.com

3

4

TYPICAL CHARACTERISTICS

At T

A

= +25

°

C, V

S

= 5V, V

CM

= V

S

/2, R

L

= 10k

, and C

L

= 100pF, unless otherwise noted.

40

30

20

10

0

80

70

60

50

–10

–20

10

Gain = 500

Gain = 100

Gain = 25

Gain = 5

100

GAIN vs FREQUENCY

1k 10k

Frequency (Hz)

100k 1M 10M

120

100

80

60

40

20

0

10

COMMON-MODE REJECTION RATIO vs FREQUENCY

100 1k

Frequency (Hz)

10k 100k

POWER-SUPPLY REJECTION RATIO vs FREQUENCY

60

50

40

30

100

90

80

70

20

10

0

1 10 100 1k

Frequency (Hz)

10k 100k

6

5

4

V

V

MAXIMUM OUTPUT VOLTAGE vs FREQUENCY

S

S

= 5.5V

= 5.0V

3

2

1

0

100

V

S

= 2.7V

1k 10k 100k

Frequency (Hz)

1M 10M

0.1Hz TO 10Hz VOLTAGE NOISE

NOISE vs FREQUENCY

10k

1k

100 1

10

1 10 100 1k

Frequency (Hz)

10k 100k

0.1

100

10

1s/div

www.ti.com

INA332, INA2332

SBOS216B

TYPICAL CHARACTERISTICS

(Cont.)

At T

A

= +25

°

C, V

S

= 5V, V

CM

= V

S

/2, R

L

= 10k

, and C

L

= 100pF, unless otherwise noted.

OUTPUT SWING vs LOAD RESISTANCE

25

20

15

10

5

To Negative Rail

0

0 10k

To Positive Rail

20k

R

LOAD

(

)

30k 40k 50k

3

2

1

0

0

6

5

4

COMMON-MODE INPUT RANGE vs REFERENCE VOLTAGE

Outside of Normal Operation

REF

Increasing

1 2 3

Input Common-Mode Voltage (V)

4 5

500

450

400

350

300

250

200

150

100

50

0

2.5

QUIESCENT CURRENT AND SHUTDOWN CURRENT vs POWER SUPPLY

3

I

I

Q

SD

3.5

4 4.5

Supply Voltage (V)

5 5.5

QUIESCENT CURRENT AND SHUTDOWN CURRENT vs TEMPERATURE

350

300

250

200

150

100

50

0

600

550

500

450

400

–75 –50 –25 0

I

Q

25 50

Temperature (

°

C)

I

SD

75 100 125

150

60

50

40

30

20

10

0

2.5

SHORT-CIRCUIT CURRENT vs POWER SUPPLY

3 3.5

I

I

SC+

SC–

4 4.5

Supply Voltage (V)

5 5.5

SHORT-CIRCUIT CURRENT vs TEMPERATURE

60

50

40

I

SC+

I

SC–

30

20

10

0

–75 –50 –25 0 25 50

Temperature (

°

C)

75

100 125 150

INA332, INA2332

SBOS216B

www.ti.com

5

TYPICAL CHARACTERISTICS

(Cont.)

At T

A

= +25

°

C, V

S

= 5V, V

CM

= V

S

/2, R

L

= 10k

, and C

L

= 100pF, unless otherwise noted.

SMALL-SIGNAL STEP RESPONSE (G = 5) SMALL-SIGNAL STEP RESPONSE (G = 100)

4

µ s/div

SMALL-SIGNAL STEP RESPONSE

(G = 5, C

L

= 1000pF)

4

µ s/div

SMALL-SIGNAL STEP RESPONSE

(G = 100, C

L

= 1000pF)

4

µ s/div

SMALL-SIGNAL STEP RESPONSE

(G = 100, C

L

= 4700pF)

10

µ s/div

LARGE-SIGNAL STEP RESPONSE (G = 25)

6

10

µ s/div

www.ti.com

10

µ s/div

INA332, INA2332

SBOS216B

TYPICAL CHARACTERISTICS

(Cont.)

At T

A

= +25

°

C, V

S

= 5V, V

CM

= V

S

/2, R

L

= 10k

, and C

L

= 100pF, unless otherwise noted.

20

10

0

1

40

30

60

50

Output 2Vp-p

Differential

Input Drive

SETTLING TIME vs GAIN

0.01%

10

Gain (V/V)

100

0.1%

1k

PERCENT OVERSHOOT vs LOAD CAPACITANCE

60

50

40

30

100

90

80

70

20

10

0

10

Output 100mVp-p

Differential Drive

100 1k

Load Capacitance (pF)

G = 5

G = 25

10k

SHUTDOWN VOLTAGE vs SUPPLY VOLTAGE

3

2.5

2

Normal Operation Mode

1.5

1

Operation in this Region is not Recommended

0.5

0

2.5

3

Shutdown Mode

Part Draws Below 1

µ

A Quiescent Current

3.5

4 4.5

Supply Voltage (V)

5 5.5

5

0

15

10

25

20

OFFSET VOLTAGE PRODUCTION DISTRIBUTION

Offset Voltage (mV)

V

OUT

V

SD

SHUTDOWN TRANSIENT BEHAVIOR

50

µ s/div

14

12

10

8

20

18

16

2

0

6

4

OFFSET VOLTAGE DRIFT

PRODUCTION DISTRIBUTION

Offset Voltage (

µ

V/

°

C)

INA332, INA2332

SBOS216B

www.ti.com

7

TYPICAL CHARACTERISTICS

(Cont.)

At T

A

= +25

°

C, V

S

= 5V, V

CM

= V

S

/2, R

L

= 10k

, and C

L

= 100pF, unless otherwise noted.

SLEW RATE vs TEMPERATURE

4

3

2

8

7

6

5

1

0

–75 –50 –25 0 25 50

Temperature (

°

C)

75 100 125 150

INPUT BIAS CURRENT vs TEMPERATURE

10000

1000

100

10

1

0.1

–75 –50 –25 0 25 50

Temperature (

°

C)

75 100 125 150

CHANNEL SEPARATION vs FREQUENCY

120

100

80

60

40

20

0

1 10 100 1k 10k

Frequency (Hz)

100k 1M 10M

5

OUTPUT VOLTAGE SWING vs OUTPUT CURRENT

4

3

125

°

C 25

°

C –55

°

C

2

1

0

0 5 10 15 20 25 30 35 40

Output Current (mA)

45 50 55 60

8

www.ti.com

INA332, INA2332

SBOS216B

APPLICATIONS INFORMATION

The INA332 is a modified version of the classic two op amp instrumentation amplifier, with an additional gain amplifier.

Figure 1 shows the basic connections for the operation of the

INA332 and INA2332. The power supply should be capacitively decoupled with 0.1

µ

F capacitors as close to the INA332 as possible for noisy or high-impedance applications.

The output is referred to the reference terminal, which must be at least 1.2V below the positive supply rail.

OPERATING VOLTAGE

The INA332 family is fully specified over a supply range of

+2.7V to +5.5V, with key parameters tested over the temperature range of –55

°

C to +125

°

C. Parameters that vary significantly with operating conditions, such as load conditions or temperature, are shown in the Typical Characteristics.

The INA332 may be operated on a single supply. Figure 2 shows a bridge amplifier circuit operated from a single +5V supply. The bridge provides a small differential voltage riding on an input common-mode voltage.

2

V

IN

V

IN

+

3

R

1

Short V

OUT

to RG for G = 5

R

2

RG

1

G = 5 + 5 (R

2

/ R

1

)

DESIRED GAIN

(V/V)

5

10

50

100

R

1

R

2

OPEN

100k

10k

10k

SHORT

100k

90k

190k

REF

5

40k

10k

40k

A1

8

Shutdown

0.1

µ

F

V+

7

10k

A2

(For Single

Supply)

V–

4

A3

0.1

µ

F

6

V

O

= ((V

IN

+) – (V

IN

–)) • G

Also drawn in simplified form:

V

IN

+

REF

V

IN

3

5

2

V+

Shutdown

7

INA332

8

6

1

4

V– RG

V

OUT

FIGURE 1. Basic Connections.

Bridge

Sensor

+5V

V

IN

+

REF (1)

V

IN

3

5

2

V+

7

Shutdown

INA332

8

6

1

4

V–

RG

V

OUT

NOTE: (1) REF should be adjusted for the desired output level, keeping in mind that the value of REF affects the common-mode input range. See Typical Characteristics.

FIGURE 2. Single-Supply Bridge Amplifier.

INA332, INA2332

SBOS216B

www.ti.com

9

SETTING THE GAIN

The ratio of R

2

to R

1

, or the impedance between pins 1, 5, and 6, determines the gain of the INA332. With an internally set gain of 5, the INA332 can be programmed for gains greater than 5 according to the following equation:

G = 5 + 5 (R

2

/R

1

)

The INA332 is designed to provide accurate gain, with gain error less than 0.4%. Setting gain with matching TC resistors will minimize gain drift. Errors from external resistors will add directly to the error, and may become dominant error sources.

COMMON-MODE INPUT RANGE

The upper limit of the common-mode input range is set by the common-mode input range of the second amplifier, A2, to

1.2V below positive supply. Under most conditions, the amplifier operates beyond this point with reduced performance. The lower limit of the input range is bounded by the output swing of amplifier A1, and is a function of the reference voltage according to the following equation:

V

OA1

= 5/4 V

CM

– 1/4 V

REF

(See typical characteristic curve, Common-Mode Input Range vs Reference Voltage).

REFERENCE

The reference terminal defines the zero output voltage level.

In setting the reference voltage, the common-mode input of

A3 should be considered according to the following equation:

V

OA2

= V

REF

+ 5 (V

IN

+ – V

IN

–)

For ensured operation, V

OA2

should be less than V

DD

– 1.2V.

The reference pin requires a low-impedance connection. As little as 160

in series with the reference pin will degrade the

CMRR to 50dB. The reference pin may be used to compensate for the offset voltage (see the Offset Trimming section).

The reference voltage level also influences the commonmode input range (see the Common-Mode Input Range section).

INPUT BIAS CURRENT RETURN

With a high input impedance of 10

13

, the INA332 is ideal for use with high-impedance sources. The input bias current of less than 10pA makes the INA332 nearly independent of input impedance and ideal for low-power applications.

For proper operation, a path must be provided for input bias currents for both inputs. Without input bias current paths, the inputs will float to a potential that exceeds common-mode range and the input amplifier will saturate. Figure 3 shows how bias current path can be provided in the cases of microphone applications, thermistor applications, ground returns, and dc-coupled resistive bridge applications.

Microphone,

Hydrophone, etc.

V

IN

+

3

REF

V

IN

5

2

V+

Shutdown

7

INA332

8

6

1

4

47k

V– RG

V

B

(1)

V

OUT

Transformer

V

B

(1)

V

IN

+

3

REF

V

IN

5

2

V+

Shutdown

7

INA332

8

6

1

4

V–

V

OUT

RG

Center-tap provides bias current return

V

EX

Bridge

Amplifier

Bridge

Sensor

V

IN

+

3

REF

V

IN

5

2

V+

Shutdown

7

INA332

8

6

1

4

V–

V

OUT

RG

Bridge resistance provides bias current return

NOTE: (1) V

B

is bias voltage within common-mode range, dependent on REF.

FIGURE 3. Providing an Input Common-Mode Path.

When differential source impedance is low, the bias current return path can be connected to one input. With higher source impedance, two equal resistors will provide a balanced input. The advantages are lower input offset voltage due to bias current flowing through the source impedance and better high-frequency gain.

10

www.ti.com

INA332, INA2332

SBOS216B

SHUTDOWN MODE

The shutdown pin of the INA332 is nominally connected to V+.

When the pin is pulled below 0.8V on a 5V supply, the INA332 goes into sleep mode within nanoseconds. For actual shutdown threshold, see typical characteristic curve, Shutdown

Voltage vs Supply Voltage. Drawing less than 2

µ

A of current, and returning from sleep mode in microseconds, the shutdown feature is useful for portable applications. Once in sleep mode, the amplifier has high output impedance, making the INA332 suitable for multiplexing.

RAIL-TO-RAIL OUTPUT

A class AB output stage with common-source transistors is used to achieve rail-to-rail output for gains of 10 or greater.

For resistive loads greater than 10k

, the output voltage can swing to within 25mV of the supply rail while maintaining low gain error. For heavier loads and over temperature, see the typical characteristic curve, Output Voltage Swing vs Output

Current. The INA332’s low output impedance at high frequencies makes it suitable for directly driving Capacitive-Input

A/D converters, as shown in Figure 4.

+5V

V

IN

+

REF

V

IN

0.1

µ

F

3

5

2

V+

7

4

Shutdown

INA332

8

6

1

V

OUT

V– RG

OPA340

0.1

µ

F

V

OUT

FIGURE 5. Output Buffering Circuit. Able to drive loads as low as 600

.

V

IN

+

REF (1)

3

5

V

IN

2

V+

Shutdown

7

INA332

8

6

1

4

V–

RG

V

OUT

+5V

V

IN

+

REF

V

IN

3

5

2

V+

7

Shutdown

INA332

8

6

V

OUT

1

4

V–

RG

ADS7818

or

ADS7822

12-Bits f

S

< 100kHz

FIGURE 4. INA332 Directly Drives Capacitive-Input, High-

Speed A/D Converter.

OUTPUT BUFFERING

The INA332 is optimized for a load impedance of 10k

or greater. For higher output current the INA332 can be buffered using the OPA340, as shown in Figure 5. The OPA340 can swing within 50mV of the supply rail, driving a 600

load.

The OPA340 is available in the tiny MSOP-8 package.

OFFSET TRIMMING

The INA332 is laser trimmed for low offset voltage. In the event that external offset adjustment is required, the offset can be adjusted by applying a correction voltage to the reference terminal. Figure 6 shows an optional circuit for trimming offset voltage. The voltage applied to the REF terminal is added to the output signal. The gain from REF to

V

OUT

is +1. An op amp buffer is used to provide low impedance at the REF terminal to preserve good commonmode rejection.

OPA336

Adjustable

Voltage

NOTE: (1) REF should be adjusted for the desired output level.

The value of REF affects the common-mode input range.

FIGURE 6. Optional Offset Trimming Voltage.

INPUT PROTECTION

Device inputs are protected by ESD diodes that will conduct if the input voltages exceed the power supplies by more than

500mV. Momentary voltages greater than 500mV beyond the power supply can be tolerated if the current through the input pins is limited to 10mA. This is easily accomplished with input resistor R

LIM

, as shown in Figure 7. Many input signals are inherently current-limited to less than 10mA; therefore, a limiting resistor is not required.

V

IN

+

V

IN

R

I

OVERLOAD

10mA max

REF

R

LIM

LIM

3

5

2

V+

Shutdown

7

INA332

8

6

1

4

V– RG

V

OUT

FIGURE 7. Sample Output Buffering Circuit.

INA332, INA2332

SBOS216B

www.ti.com

11

OFFSET VOLTAGE ERROR CALCULATION

The offset voltage (V

OS

) of the INA332AIDGK is specified at a maximum of 500

µ

V with a +5V power supply and the common-mode voltage at V

S

/2. Additional specifications for power-supply rejection and common-mode rejection are provided to allow the user to easily calculate worst-case expected offset under the conditions of a given application.

Power-Supply Rejection Ratio (PSRR) is specified in

µ

V/V.

For the INA332, worst case PSRR is 200

µ

V/V, which means for each volt of change in power supply, the offset may shift up to 200

µ

V. Common-Mode Rejection Ratio (CMRR) is specified in dB, which can be converted to

µ

V/V using the following equation:

CMRR (in

µ

V/V) = 10

[(CMRR in dB)/–20]

• 10

6

For the INA332, the worst case CMRR over the specified common-mode range is 60dB (at G = 25) or about 30

µ

V/V

This means that for every volt of change in common-mode, the offset will shift less than 30

µ

V.

These numbers can be used to calculate excursions from the specified offset voltage under different application conditions. For example, an application might configure the amplifier with a 3.3V supply with 1V common-mode. This configuration varies from the specified configuration, representing a

1.7V variation in power supply (5V in the offset specification versus 3.3V in the application) and a 0.65V variation in common-mode voltage from the specified V

S

/2.

Calculation of the worst-case expected offset would be as follows:

Adjusted V

OS

= Maximum specified V

OS

+

(power-supply variation) • PSRR +

(common-mode variation) • CMRR

V

OS

= 0.5mV + (1.7V • 200

µ

V) + (0.65V • 30

µ

V)

=

±

0.860mV

However, the typical value will be smaller, as seen in the

Typical Characteristics.

FEEDBACK CAPACITOR IMPROVES RESPONSE

For optimum settling time and stability with high-impedance feedback networks, it may be necessary to add a feedback capacitor across the feedback resistor, R

F

, as shown in

Figure 8. This capacitor compensates for the zero created by the feedback network impedance and the INA332’s RG-pin input capacitance (and any parasitic layout capacitance).

The effect becomes more significant with higher impedance networks. Also, R

X

and C

L

can be added to reduce highfrequency noise.

V

IN

+

REF

V

IN

3

5

2

V+

INA332

7

Shutdown

8

6

C

IN

4

1

RG

R

IN

V–

R

F

C

F

R

X

C

L

V

OUT

R

IN

• C

IN

= R

F

• C

F

Where C

IN is equal to the INA332’s input capacitance

(approximately 3pF) plus any parastic layout capacitance.

FIGURE 8. Feedback Capacitor Improves Dynamic Performance.

It is suggested that a variable capacitor be used for the feedback capacitor since input capacitance may vary between instrumentation amplifiers, and layout capacitance is difficult to determine. For the circuit shown in Figure 8, the value of the variable feedback capacitor should be chosen by the following equation:

R

IN

• C

IN

= R

F

• C

F

Where C

IN

is equal to the INA332’s RG-pin input capacitance

(typically 3pF) plus the layout capacitance. The capacitor can be varied until optimum performance is obtained.

12

www.ti.com

INA332, INA2332

SBOS216B

APPLICATION CIRCUITS

MEDICAL ECG APPLICATIONS

Figure 9 shows the INA332 configured to serve as a low-cost

ECG amplifier, suitable for moderate accuracy heart-rate applications such as fitness equipment. The input signals are obtained from the left and right arms of the patient. The common-mode voltage is set by two 2M

resistors. This potential through a buffer provides optional right leg drive.

Filtering can be modified to suit application needs by changing the capacitor value of the output filter.

LOW-POWER, SINGLE-SUPPLY DATA

ACQUISITION SYSTEMS

Refer to Figure 4 to see the INA332 configured to drive an

ADS7818. Functioning at frequencies of up to 500kHz, the

INA332 is ideal for low-power data acquisition.

100k

Left Arm

Right Arm

+5V

100k

2k

V

R

= +2.5V

2k

2M

V

R

OPA336

0.1

µ

F

V

IN

+

3

REF

5

V

IN

2

V+

Shutdown

7

INA332

8

6

1

4

V–

2M

RG

V

R

1M

10k

10k

OPA336

Right

Leg

1.6nF

1M

1M

OPA336

V

OUT PUT

FIGURE 9. Simplified ECG Circuit for Medical Applications.

INA332, INA2332

SBOS216B

www.ti.com

13

www.ti.com

PACKAGE OPTION ADDENDUM

12-Sep-2006

PACKAGING INFORMATION

Orderable Device

INA2332AIPWR

INA2332AIPWRG4

INA2332AIPWT

INA2332AIPWTG4

INA332AIDGKR

INA332AIDGKRG4

INA332AIDGKT

INA332AIDGKTG4

Status

(1)

ACTIVE

ACTIVE

ACTIVE

ACTIVE

ACTIVE

ACTIVE

ACTIVE

ACTIVE

Package

Type

TSSOP

TSSOP

TSSOP

TSSOP

MSOP

MSOP

MSOP

MSOP

Package

Drawing

PW

PW

PW

PW

DGK

DGK

DGK

DGK

Eco Plan

(2)

Pins Package

Qty

14 2500 Green (RoHS & no Sb/Br)

Lead/Ball Finish MSL Peak Temp

(3)

CU NIPDAU Level-2-260C-1 YEAR

14 CU NIPDAU Level-2-260C-1 YEAR

14

2500 Green (RoHS & no Sb/Br)

250 Green (RoHS & no Sb/Br)

CU NIPDAU Level-2-260C-1 YEAR

14 CU NIPDAU Level-2-260C-1 YEAR

8

8

8

8

250 Green (RoHS & no Sb/Br)

2500 Green (RoHS & no Sb/Br)

2500 Green (RoHS & no Sb/Br)

250 Green (RoHS & no Sb/Br)

250 Green (RoHS & no Sb/Br)

CU NIPDAU

CU NIPDAU

CU NIPDAU

CU NIPDAU

Level-2-260C-1 YEAR

Level-2-260C-1 YEAR

Level-2-260C-1 YEAR

Level-2-260C-1 YEAR

(1)

The marketing status values are defined as follows:

ACTIVE: Product device recommended for new designs.

LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.

NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.

PREVIEW: Device has been announced but is not in production. Samples may or may not be available.

OBSOLETE: TI has discontinued the production of the device.

(2)

Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details.

TBD: The Pb-Free/Green conversion plan has not been defined.

Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.

Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.

Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material)

(3)

MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.

Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.

In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.

Addendum-Page 1

www.ti.com

TAPE AND REEL INFORMATION

PACKAGE MATERIALS INFORMATION

30-Jan-2009

*All dimensions are nominal

Device

INA2332AIPWR

INA2332AIPWT

INA332AIDGKR

INA332AIDGKT

Package

Type

Package

Drawing

TSSOP

TSSOP

MSOP

MSOP

PW

PW

DGK

DGK

Pins

14

14

8

8

SPQ

2500

250

2500

250

Reel

Diameter

(mm)

Reel

Width

W1 (mm)

330.0

12.4

180.0

330.0

180.0

12.4

12.4

12.4

A0 (mm)

7.0

7.0

5.3

5.3

B0 (mm)

5.6

5.6

3.4

3.4

K0 (mm) P1

(mm)

W

(mm)

Pin1

Quadrant

1.6

1.6

1.4

1.4

8.0

8.0

8.0

8.0

12.0

12.0

12.0

12.0

Q1

Q1

Q1

Q1

Pack Materials-Page 1

www.ti.com

PACKAGE MATERIALS INFORMATION

30-Jan-2009

*All dimensions are nominal

Device

INA2332AIPWR

INA2332AIPWT

INA332AIDGKR

INA332AIDGKT

Package Type Package Drawing Pins

TSSOP

TSSOP

MSOP

MSOP

PW

PW

DGK

DGK

14

14

8

8

SPQ

2500

250

2500

250

Length (mm) Width (mm) Height (mm)

346.0

190.5

346.0

190.5

346.0

212.7

346.0

212.7

29.0

31.8

29.0

31.8

Pack Materials-Page 2

MECHANICAL DATA

MTSS001C – JANUARY 1995 – REVISED FEBRUARY 1999

PLASTIC SMALL-OUTLINE PACKAGE PW (R-PDSO-G**)

14 PINS SHOWN

0,65

14 8

0,30

0,19

0,10

M

1

A

7

4,50

4,30

6,60

6,20

0,15 NOM

Gage Plane

0

°

– 8

°

0,25

0,75

0,50

1,20 MAX

0,15

0,05

Seating Plane

0,10

DIM

PINS **

A MAX

8

3,10

A MIN 2,90

14

5,10

4,90

16

5,10

20

6,60

4,90 6,40

24

7,90

28

9,80

7,70 9,60

4040064/F 01/97

NOTES: A. All linear dimensions are in millimeters.

B. This drawing is subject to change without notice.

C. Body dimensions do not include mold flash or protrusion not to exceed 0,15.

D. Falls within JEDEC MO-153

POST OFFICE BOX 655303

DALLAS, TEXAS 75265

IMPORTANT NOTICE

Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment.

TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed.

TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards.

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Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements.

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DLP® Products

DSP

Clocks and Timers

Interface

Logic

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www.dlp.com

dsp.ti.com

www.ti.com/clocks interface.ti.com

logic.ti.com

power.ti.com

microcontroller.ti.com

www.ti-rfid.com

RF/IF and ZigBee® Solutions www.ti.com/lprf

Applications

Audio

Automotive

Broadband

Digital Control

Medical

Military

Optical Networking

Security

Telephony

Video & Imaging

Wireless www.ti.com/audio www.ti.com/automotive www.ti.com/broadband www.ti.com/digitalcontrol www.ti.com/medical www.ti.com/military www.ti.com/opticalnetwork www.ti.com/security www.ti.com/telephony www.ti.com/video www.ti.com/wireless

Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265

Copyright © 2009, Texas Instruments Incorporated

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