5

Application information

5.1

Operating voltages

The TSV771 and TSV772 devices can operate from 2.0 to 5.5 V. The parameters are fully specified at 2.0 V,

3.3 V and 5 V power supplies. However, the parameters are very stable over the full VCC range and several

characterization curves show the TSV771 and TSV772 devices characteristics over the full operating range.

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

The TSV772 device is rail-to-rail input and output and features two input transistor pairs, allowing the op amp to

operate over all the common mode range, from Vcc- - 0.2 V, to Vcc+ + 0.1 V. The input pair transition typically

occurs at Vcc+ - 1 V, as seen in Figure 11 and Figure 12. The precision and dynamic performances are particularly

optimized on the low pair, from Vcc- - 0.1 V to Vcc+ - 1.8 V, and operating in this Vicm range is advised for the best

performance whenever possible. Besides, operating near the pair transition should be avoided when precision is

a concern, as CMRR can be lower in these conditions.

5.2

Input offset voltage drift over the temperature

The input voltage drift variation over the temperature 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 (Vio) is a major contributor to the chain accuracy. The signal chain accuracy at 25 °C can be

compensated during the production at the application level. The maximum input voltage drift over the temperature

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 datasheet maximum value is guaranteed by a measurement on a representative sample size ensuring a Cpk

(process capability index) greater than 1.3. The absolute worst case value between -40 °C and 125 °C is reported

in the datasheet.

5.3

Unused channel

When one of the two channels of TSV771 and TSV772 are 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:

Gain or buffer configuration: the channel can be set in gain, the input can be set to any voltage within the Vicm

operating 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 and within operating range) and the

differential input is lower than the maximum specified in the operating range.

TSV771, TSV772

Application information

DS13842 - Rev 3

page 18/32