2.0

1.8

1.6

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

0

2

4

6

8

10

12

14

16

18

V

(mV)

SENSE

20

Actual

Ideal

20

INA200, INA201, INA202

SBOS374E – NOVEMBER 2006 – REVISED SEPTEMBER 2017

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Copyright © 2006–2017, Texas Instruments Incorporated

Device Functional Modes (continued)

7.4.2.2 Normal Case 2: VSENSE ≥ 20 mv, VCM < VS

This region of operation is less accurate than normal case 1 as a result of the common-mode operating area in

which the part functions, as shown in the Figure 7 curve (Figure 7). As noted, for this graph VS = 12 V; for VCM <

12 V, the output error increases as VCM decreases to less than 12 V, with a typical maximum error of 0.005% at

the most negative VCM = –16 V.

7.4.2.3 Low VSENSE Case 1: VSENSE < 20 mV, –16 V ≤ VCM < 0

and Low VSENSE Case 3: VSENSE < 20 mV, VS < VCM ≤ 80 V

Although the INA200 family of devices are not designed for accurate operation in these regions, some

applications are exposed to these conditions. For example, when monitoring power supplies that are switched on

and off while VS is still applied to the INA20x devices, it is important to know what the behavior of the devices is

in these regions.

As VSENSE approaches 0 mV, in these VCM regions, the accuracy of the device output degrades. A larger-than-

normal offset can appear at the current shunt monitor output with a typical maximum value of VOUT = 300 mV for

VSENSE = 0 mV. As VSENSE approaches 20 mV, VOUT returns to the expected output value with accuracy as

shown in Electrical Characteristics: Current-Shunt Monitor. Figure 32 shows this effect using the INA202 (gain =

100).

Figure 32. Example For Low VSENSE Cases 1 and 3 (INA202, Gain = 100)

7.4.2.4 Low VSENSE Case 2: VSENSE < 20 mV, 0 V ≤ VCM ≤ VS

This region of operation is the least accurate for the INA20x family. To achieve the wide input common-mode

voltage range, these devices use two op amp front ends in parallel. One op amp front end operates in the

positive input common-mode voltage range, and the other in the negative input region. For this case, neither of

these two internal amplifiers dominates and overall loop gain is low. Within this region, VOUT approaches voltages

close to linear operation levels for normal case 2. This deviation from linear operation becomes greatest the

closer VSENSE approaches 0 V. Within this region, as VSENSE approaches 20 mV, device operation is closer to that

is described in normal case 2. Figure 33 shows this behavior for the INA202. The VOUT maximum peak for this

case is tested by maintaining a constant VS, setting VSENSE equal to 0 mV and sweeping VCM from 0 V to VS. The

exact VCM at which VOUT peaks during this test varies from device to device, but the VOUT maximum peak is

tested to be less than the specified VOUT tested limit.