Frequency (Hz)

0

5

10

15

20

25

30

35

40

1

10

100

1k

10k

100k

1M

+

±

GND

R2

R1

Bias Current Cancellation Resistor = R1//R2

+

±

GND

Copyright © 2017, Texas Instruments Incorporated

Not recommended

18

OPA207

SBOS826A – DECEMBER 2017 – REVISED DECEMBER 2018

www.ti.com

Product Folder Links: OPA207

Submit Documentation Feedback

Copyright © 2017–2018, Texas Instruments Incorporated

Feature Description (continued)

Figure 44. Bias Current Cancellation Resistor — Not Recommended

7.3.7 Slew Boost

The OPA207 uses a novel internal slew-boost technique. This method allows the OPA207 to consume very low

power yet still achieve a high slew rate of 3.6 V/µs. This makes the OPA207 ideal for applications that require

low noise and high out voltage swings where the high slew rate is necessary to achieve fast settling times.

Figure 45. Full Power Bandwidth

7.3.8 EMI Rejection Ratio (EMIRR)

The electromagnetic interference (EMI) rejection ratio, or EMIRR, describes the EMI immunity of operational

amplifiers. An adverse effect that is common to many operational amplifiers is a change in the offset voltage as a

result of RF signal rectification. An operational amplifier that is more efficient at rejecting this change in offset as

a result of EMI has a higher EMIRR and is quantified by a decibel value. Measuring EMIRR can be performed in

many ways, but this report provides the EMIRR IN+, which specifically describes the EMIRR performance when

the RF signal is applied to the noninverting input pin of the operational amplifier. In general, only the noninverting

input is tested for EMIRR for the following three reasons:

1. Operational amplifier input pins are known to be the most sensitive to EMI, and typically rectify RF signals

better than the supply or output pins.

2. The noninverting and inverting operational amplifier inputs have symmetrical physical layouts and exhibit

nearly matching EMIRR performance.

3. EMIRR is easier to measure on noninverting pins than on other pins because the noninverting input terminal

can be isolated on a printed circuit board (PCB). This isolation allows the RF signal to be applied directly to

the noninverting input terminal with no complex interactions from other components or connecting PCB

traces.

A more formal discussion of the EMIRR IN+ definition and test method is provided in TI Application Report EMI

Rejection Ratio of Operational Amplifiers, available for download at www.ti.com. The EMIRR IN+ of the OPA207

is plotted versus frequency as shown in Figure 46.