The present disclosure generally relates to junction diode isolation in an integrated circuit die. In an example, a semiconductor device includes a diode and a transistor. The diode is in a semiconductor substrate. The diode includes an anode region, an n-type well, a cathode region, and an n-type buried layer each in the semiconductor substrate. The cathode region is in the n-type well. The n-type buried layer extends from the n-type well laterally towards the anode region. The transistor includes a source region and a drain region in the semiconductor substrate. The source and drain regions are between the anode and cathode regions. A lateral distance is between the cathode region and a lateral edge of the n-type buried layer proximate the anode region. The lateral distance is parallel to a channel length of the transistor. The lateral distance decreases from proximate the transistor to distal from the transistor.

A rectifier includes a first transistor of a drain/source common field effect type and a second transistor of a drain/source common field effect type in which the second transistor is diode-connected to the first transistor so as to allow the first transistor to perform a diode operation, and configures a rectifier stage with the first transistor.