Temperature stability is one of the indicators showing the stability of components and circuits. Its literal meaning indicates how much the output of such items is affected when temperature changes.
In the case of preamplifiers, temperature fluctuation of offset voltage (“offset drift”) may be particularly important. The offset voltage of a preamplifier fluctuates because the characteristics of the device (a transistor) used for the input are greatly related.
In general, bipolar transistor input tends to have small offset drift (about ± 1 µV / °C or less) and FET input tends to be large (about ± 5 to 20 µV / °C) in reverse.
Offset drifts of the main preamplifiers offered in our lineup are summarized below in the Table. The bipolar-transistor inputs achieve the best offset drift characteristics by more than one order of magnitude.
It is most effective to use the preamplifier in a place where the temperature is stable; however, if it is desirable to reduce the influence of temperature variation, a preamplifier with a bipolar transistor input is effective.
|Model||Offset drift||Input device|
Related keywords : Ultra low noise amplifier, LNA