5

Application information

5.1

Operating voltages

The TSV7722 device can operate from 1.8 to 5.5 V. The parameters are fully specified at 1.8 V, 3.3 V

characterization curves show the TSV7722 device characteristics over the full operating range. Additionally, the

main specifications are guaranteed in extended temperature range from - 40 to 125 °C.

5.2

Input offset voltage drift over the temperature

The maximum input voltage drift variation overtemperature is defined as the offset variation related to the offset

value measured at 25 °C. The operational amplifier is one of the main circuits of the signal conditioning chain, and

the amplifier input offset is a major contributor to the chain accuracy. The signal chain accuracy at 25 °C can be

compensated during production at application level. The maximum input voltage drift overtemperature enables the

system designer to anticipate the effect of temperature variations.

The maximum input voltage drift overtemperature is computed using the following equation:

∆Vio∆T=maxVioT−Vio25°C

T−25°C

(1)

Where T = - 40 °C and 125 °C.

The TSV7721, TSV7722, TSV7723 datasheet maximum value is guaranteed by measurements on a

5.3

Unused channel

When one of the two channels of the TSV7722 is not used, it must be properly connected in order to avoid

internal oscillations that can negatively impact the signal integrity on the other channel, as well as the current

consumption. Two different configurations can be used:

range.

Comparator configuration: the channel can be set to a comparator configuration (without negative feedback). In

this case, positive and negative inputs can be set to any value provided these values are significantly different

(100 mV or more, to avoid oscillation between positive and negative state).

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 TSV7722 has been specially designed to minimize susceptibility to EMIRR and shows a low sensitivity. As

can be seen in Figure 46. 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.

TSV7721, TSV7722, TSV7723

Application information

DS13614 - Rev 3

page 19/40