Characterization of Changes in LDO Susceptibility After Electrical Stress

The low dropout voltage regulator (LDO) is very sensitive to electromagnetic interference (EMI) coupled onto the power supply, with concomitant output voltage offset. Most electromagnetic compatibility analyses of the LDO do not account for the effects of ageing. However, device ageing can degrade the physical parameters of semiconductor devices and can worsen the effect of EMI. This paper analyses the drift in LDO immunity after accelerated ageing. A large number of measurements that show the variations in the test results for dc characteristic, impedance, and immunity reveal increasing susceptibility after electrical accelerated ageing.