300Ω

+5V

R

G

INA128

V

O

Ref

2.5V − ∆V

2.5V + ∆V

G = 1

5V/div

G = 10

5 s/div

m

5V/div

G =1000

20 s/div

m

G =100

INA128, INA129

SBOS051C – OCTOBER 1995 – REVISED OCTOBER 2015

www.ti.com

Typical Application (continued)

G = 1, 10

G = 100, 1000

Figure 29. Large Signal

Figure 30. Large Signal

9 Power Supply Recommendations

The minimum power supply voltage for INA12x is ±2.25 V and the maximum power supply voltage is ±18 V. This

minimum and maximum range covers a wide range of power supplies; but for optimum performance, ±15 V is

recommended. TI recommends adding a bypass capacitor at the input to compensate for the layout and power

supply source impedance.

9.1 Low Voltage Operation

The INA12x can be operated on power supplies as low as ±2.25 V. Performance remains excellent with power

supplies ranging from ±2.25 V to ±18 V. Most parameters vary only slightly throughout this supply voltage

range—see Typical Characteristics.

Operation at very low supply voltage requires careful attention to assure that the input voltages remain within

their linear range. Voltage swing requirements of internal nodes limit the input common-mode range with low

power supply voltage. Figure 6 shows the range of linear operation for ±15-V, ±5-V, and ±2.5-V supplies.

Figure 31. Bridge Amplifier

16

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