OA1NP Datasheet, PDF (17/31 Pages) STMicroelectronics – Rail-to-rail input and output

OA1NP, OA2NP, OA4NP
4
Application information
Application information
4.1
Operating voltages
The OA1NP, OA2NP and OA4NP series of low power op amp can operate from 1.5 V to
5.5 V. Their parameters are fully specified at 1.8 V, 3.3 V, and 5 V supply voltages and are
very stable in the full V_CC range. Additionally, main specifications are guaranteed on the
industrial temperature range from -40 to +85 ° C.
4.2
Rail-to-rail input
The OA1NP, OA2NP and OA4NP series is built with two complementary PMOS and NMOS
input differential pairs. Thus, these devices have a rail-to-rail input, and the input common
mode range is extended from V_CC- - 0.1 V to V_CC+ + 0.1 V.
The devices have been designed to prevent phase reversal behavior.
4.3
Input offset voltage drift over temperature
The maximum input voltage drift over the temperature variation 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 effects of temperature variations.
The maximum input voltage drift over temperature is computed in Equation 1.
Equation 1
_-----V_{--T--i-o- = max V-----i-o-----T---T-----––-----V2---5-i-o----C--2---5------C------}
with T = -40 °C and 85 °C.
The datasheet maximum value is guaranteed by measurements on a representative sample
size ensuring a C_pk (process capability index) greater than 2.
DocID025993 Rev 2
17/31
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