PRODUCT

GAIN

INA282

50V/V

INA283

200V/V

INA284

500V/V

INA285

1000V/V

INA286

100V/V

33.3kW

33.3kW

1

Æ

2

Æ

2

Æ

1

Æ

2

Æ

2

Zer

-

Drift

Æ

OUT

REF2

REF1

GND

V+=5V

V+

SeeNote(1)

Connectto 10V

-

Supply

24Vto+70V

-

Load

+IN

-

IN

Æ

1

Æ

1

INA282, INA283

INA284, INA285

INA286

SBOS485A – NOVEMBER 2009 – REVISED JULY 2010

www.ti.com

EXTENDED NEGATIVE COMMON-MODE RANGE

Using a negative power supply can extend the common-mode range 14V more negative than the supply used.

For instance, a –10V supply allows up to –24V negative common-mode. Remember to keep the total voltage

between the GND pin and V+ pin to less than 18V. The positive common-mode decreases by the same amount.

The reference input simplifies this type of operation because the output quiescent bias point is always based on

the reference connections. Figure 39 shows a circuit configuration for common-mode ranges from –24V to +70V.

(1)

Connect the REF pins as desired; however, they cannot exceed 9V above the GND pin voltage.

Figure 39. Circuit Configuration for Common-Mode Ranges from –24V to +70V

CALCULATING TOTAL ERROR

The electrical specifications for the INA282-286 family of devices include the typical individual errors terms such

as gain error, offset error, and nonlinearity error. Total error including all of these individual error components is

not specified in the Electrical Characteristics table. In order to accurately calculate the error that can be expected

from the device, we must first know the operating conditions to which the device is subjected. Some current

shunt monitors specify a total error in the product data sheet. However, this total error term is accurate under

only one particular set of operating conditions. Specifying the total error at this one point has little practical value

because any deviation from these specific operating conditions no longer yields the same total error value. This

section discusses the individual error sources, with information on how to apply them in order to calculate the

total error value for the device under any normal operating conditions.

The typical error sources that have the largest impact on the total error of the device are input offset voltage,

common-mode voltage rejection, gain error and nonlinearity error. For the INA282-286, an additional error source

referred to as Reference Common-Mode Rejection is also included in the total error value.

20

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