TSB572 Datasheet, PDF (18/27 Pages) STMicroelectronics – Low-power, 2.5 MHz, RR IO, 36 V BiCMOS operational amplifier

Application information
TSB572
4.4
4.5
18/27
Input offset voltage drift over temperature
The maximum input voltage drift variation over 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 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 over temperature
enables the system designer to anticipate the effect of temperature variations.
The maximum input voltage drift over temperature is computed using Equation 1.
Equation 1
∆V_io
∆T
=
ma x ^Vio
T – V_io 25 °C
T – 25 °C
where T = -40 °C and 125 °C.
The TSB572 datasheet maximum value is guaranteed by measurements on a
representative sample size ensuring a C_pk (process capability index) greater than 1.3.
Long term input offset voltage drift
To evaluate product reliability, two types of stress acceleration are used:
Voltage acceleration, by changing the applied voltage
Temperature acceleration, by changing the die temperature (below the maximum
junction temperature allowed by the technology) with the ambient temperature.
The voltage acceleration has been defined based on JEDEC results, and is defined using
Equation 2.
Equation 2
A_FV
=
β.
e
V_S – V_U
Where:
A_FV is the voltage acceleration factor
β is the voltage acceleration constant in 1/V, constant technology parameter (β = 1)
V_S is the stress voltage used for the accelerated test
V_U is the voltage used for the application
The temperature acceleration is driven by the Arrhenius model, and is defined in
Equation 3.
Equation 3
E_{--k---a- .}
A_FT = e
1_–1
T_U T_S
Where:
A_FT is the temperature acceleration factor
E_a is the activation energy of the technology based on the failure rate
DocID028308 Rev 2