1/f noise as a prediction of long-term instability in integrated operational amplifiers

It is shown from the accelerated life test and noise measurement that the long-term instability of integrated operational amplifiers due to the drift of input bias/offset current is strongly correlated with 1/f noise in the devices, and the current drift is approximately proportional to 1/f noise current measured before the test. In the mechanism analysis, the instability and the 1/f noise may be attributed to the same physical source and both are caused by the modulation of oxide traps to Si surface carriers. 1/f noise measurement may therefore be applied as a fast and nondestructive tool to predict the long-term instability of operational amplifiers.