Circuits and methods for reliable startup of bandgap reference circuits

Abstract

A method for obtaining reliable startup of a bandgap reference circuit, the bandgap reference circuit including a bandgap core with at least two branches, a feedback loop, and a startup circuit. The method includes generating a startup stimulus with an initial magnitude sufficient to transition the circuit from an inactive state to an active state, controlling the decline of the startup stimulus by regulating its reduction progressively over time, and modifying local time constants of the bandgap reference circuit to prevent a condition in which the transient decline of a voltage across a first branch is faster than the transient decline of a voltage across a second branch. By doing so, the voltages across the branches of the bandgap core converge to a target operating point, ensuring a reliable startup of the bandgap reference circuit.

Dependencies are inferred from the claim text.