The Vio final drift, in µV, to be measured on the device in real operation conditions can be computed from:

(8)

Where:

5.6

EMI rejection

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

amplifiers. An adverse effect that is common to many op-amps is a change in the offset voltage as a result of RF

signal rectification. EMIRR is defined as follows:

EMIRR=20.log VinppΔVio

(9)

The TSB7191, TSB7191A, TSB7192 and TSB7192A have been specially designed to minimize susceptibility to

EMIRR and shows a low sensitivity. As visible on figure below, EMI rejection ratio has been measured on both

inputs and outputs, from 400 MHz to 2.4 GHz.

EMIRR performance might be improved by adding small capacitances (in the pF range) on the inputs, power

supply and output pins. These capacitances help in minimizing the impedance of these nodes at high frequencies.

5.7

Minimum gain

The TSB7191 and TSB7192 series is non-compensated op-amp, and thus it is not stable at unity gain. The

stability at all biases and temperatures. For a lower gain, the TSB712 series must be preferred.

However, a TSB7191 and TSB7192 op-amp can be used in follower mode at low frequency, provided that the

circuit is externally compensated. This can be useful for the second channel, when the TSB7192 frequency or

slew rate performance is needed for the first channel. In this case, the circuit topology described in the figure

below can be used. At low frequency, the circuit behaves as a follower, but at high frequency (>1 MHz), the circuit

is stabilized by attenuating the feedback injected into the negative input.

TSB7191, TSB7191A, TSB7192, TSB7192A

EMI rejection

DS12641 - Rev 5

page 20/34