+

±

GND

R2

R1

Bias Current Cancellation Resistor = R1//R2

+

±

GND

Copyright © 2017, Texas Instruments Incorporated

Not recommended

Temperature (qC)

-50

-25

0

25

50

75

100

125

-1000

0

1000

2000

3000

4000

5000

6000

OPA2

OPA207

Typical CMOS/JFET

17

OPA207

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SBOS826D – DECEMBER 2017 – REVISED OCTOBER 2019

Product Folder Links: OPA207

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Feature Description (continued)

7.3.6 Low Input Bias Current

The OPA207 uses super-beta bipolar transistors and employs an input bias current cancellation technique. This

combination results in very low input bias currents that remain low over the full specified temperature range from

–40°C to + 125°C unlike CMOS or JFET amplifiers whose input bias currents typically double every 10°C and

can be extremely high at 125°C. Figure 43 illustrates the comparison between the OPA207 and typical CMOS or

JFET amplifiers.

Figure 43. Input Bias Current vs Temperature

It is common practice to place a bias current cancellation resistor as illustrated in Figure 42. This approach works

well with amplifiers that do not employ an internal input bias current cancellation technique. Because the

OPA207 uses an internal bias current cancellation technique, TI does not recommend the bias cancellation

resistor.

Figure 44. Bias Current Cancellation Resistor — Not Recommended