7.3.1.1 Input-Signal Bandwidth

The INA280 –3-dB bandwidth is gain dependent with several gain options of 20 V/V, 50 V/V, 100 V/V, 200 V/V,

and 500 V/V as shown in Figure 6-2. The unique multistage design enables the amplifier to achieve high

bandwidth at all gains. This high bandwidth provides the throughput and fast response that is required for the

rapid detection and processing of overcurrent events.

The bandwidth of the device also depends on the applied VSENSE voltage. Figure 7-2 shows the bandwidth

performance profile of the device over frequency as output voltage increases for each gain variation. As shown

in Figure 7-2, the device exhibits the highest bandwidth with higher VSENSE voltages, and the bandwidth is higher

with lower device gain options. Individual requirements determine the acceptable limits of error for high-

frequency, current-sensing applications. Testing and evaluation in the end application or circuit is required to

determine the acceptance criteria and validate whether or not the performance levels meet the system

specifications.

Output Voltage (V)

0

0.5

1

1.5

2

2.5

3

3.5

4

200

300

400

500

600

700

800

900

1000

1100

1200

G = 20

G = 50

G = 100

G = 200

G = 500

Figure 7-2. Bandwidth vs Output Voltage

7.3.1.2 Low Input Bias Current

The INA280 input bias current draws 20 μA (typical) even with common-mode voltages as high as 120 V. This

enables precision current sensing in applications where the sensed current is small or applications that require

lower input leakage current.

7.3.1.3 Multiple Fixed Gain Outputs

The INA280 gain error is < 0.5% at room temperature for all gain options, with a maximum drift of 20ppm/°C over

the full temperature range of –40 °C to +125 °C. The INA280 is available in multiple gain options of 20 V/V, 50

V/V, 100 V/V, 200 V/V, and 500 V/V, which the system designer should select based on their desired signal-to-

noise ratio and other system requirements.

The INA280 closed-loop gain is set by a precision, low-drift internal resistor network. Even though the ratio of

these resistors are well matched, the absolute value of these reisistors may vary significantly. TI does not

recommend adding additional resistance around the INA280 to change the effective gain because of this

variation, however. The typical values of the gain resistors are described in Table 7-1.

Table 7-1. Fixed Gain Resistor

GAIN

R1

RL

20 (V/V)

25 kΩ

500 kΩ

50 (V/V)

10 kΩ

500 kΩ

100 (V/V)

10 kΩ

1000 kΩ

200 (V/V)

5 kΩ

1000 kΩ

500 (V/V)

2 kΩ

1000 kΩ

INA280

SBOSA19 – OCTOBER 2020

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