12V)

-

CM

1

CMRR_dB

20

(

10

R

(2.048V

V

)

-

CMR

REF

´

(V ) +(V

) +(V

)

OS

OS_CM

OS_REF

2

2

2

V

V

OS_Total

SENSE

(Error_V ) +(Error_Gain) +(Error_Lin)

OS

2

2

2

Æ

1

Æ

2

Æ

2

Æ

1

Æ

2

Æ

2

Æ

1

Æ

1

V

IN+

V

IN-

V

REF

GND

V

+

Æ

1

Æ

2

Æ

2

Æ

1

Æ

2

Æ

2

V

IN+

V

IN-

GND

V

+

Æ

1

Æ

2

Æ

2

Æ

1

Æ

2

Æ

2

V

IN+

V

IN-

GND

V

+

Output

Output

Output

Summed

Output

FirstCircuit

SecondCircuit

ThirdCircuit

Æ

1

Æ

1

INA282, INA283

INA284, INA285

INA286

SBOS485A – NOVEMBER 2009 – REVISED JULY 2010

www.ti.com

Example 2

Table 2. Example 2

TERM

SYMBOL

EQUATION

TYPICAL VALUE

MAXIMUM VALUE

Initial Input Offset

—

20mV

70mV

Voltage

Added Input Offset

Voltage Because of

1.2mV

12mV

Common-Mode

Voltage

Added Input Offset

Voltage Because of

34.8mV

92.2mV

Reference Voltage

Total Input Offset

40.2mV

116.4mV

Voltage

Error from Input

0.40%

1.16%

Offset Voltage

Gain Error

Error_Gain

—

0.40%

1.40%

Nonlinearity Error

Error_Lin

—

0.01%

0.01%

Total Error

—

0.57%

1.82%

SUMMING CURRENTS AND PARALLELING

The outputs of multiple INA282 family devices are easily summed by connecting the output of one INA282 family

device to the reference input of a second INA282 family device. Summing beyond two devices is possible by

repeating this connection, and is shown for three devices in Figure 40. The reference input of the first INA282

family device sets the output quiescent level for all the devices in the string.

NOTE: The voltage applied to the reference inputs cannot exceed 9V.

Figure 40. Summing the Outputs of Multiple INA282 Family Devices

22

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