5.4

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 in Eq. (2):

EMIRR=20.log Vin pp∆Vio

(2)

The TSV771 and TSV772 have been specially designed to minimize susceptibility to EMIRR and shows a low

sensitivity. As can be seen in Figure 44. EMIRR on In+, In- and Out pins, EMI rejection ratio has been measured

on both inputs and output, from 400 MHz to 2.4 GHz.

Figure 44. EMIRR on In+, In- and Out pins

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

supply and output pins.

These capacitances help to minimize the impedance of these nodes at high frequencies.

5.5

Maximum power dissipation

The usable output load current drive is limited by the maximum power dissipation allowed by the device package.

The absolute maximum junction temperature for the TSV772 is 150 °C. The junction temperature can be

estimated as follows:

TJ=PD×θJA+TA

(3)

TJ is the die junction temperature

PD is the power dissipated in the package

θJA is the junction-to-ambient thermal resistance of the package

TA is the ambient temperature

The power dissipated in the package PD is the sum of the quiescent power dissipated and the power dissipated

by the output stage transistor. It is calculated as follows:

PD= VCC×ICC + VCC+−VOUT ×ILoadwhentheopampissourcingthecurrent.

PD= VCC×ICC + VOUT−VCC− ×ILoadwhentheopampissinkingthecurrent.

Do not exceed the 150 °C maximum junction temperature for the device. Exceeding the junction temperature limit

can cause degradation in the parametric performance or even destroy the device.

TSV771, TSV772

EMI rejection

DS13842 - Rev 3

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