Patent ID: 9110643
Filing Date: 2015-08-18
Classification: G06F,H03K

Abstract:
1. An integrated circuit comprising: a virtual power supply rail coupled via at least one operational mode transistor to a first power supply having a first voltage level; functional circuitry coupled to said virtual power supply rail to draw power therefrom at a virtual rail voltage; control circuitry coupled to said at least one operational mode transistor and configured to supply a control voltage with a control voltage level to said at least one operational mode transistor to control current flow through said at least one operational mode transistor, wherein said control voltage provides a gate bias voltage to said at least one operational mode transistor; and voltage sensor circuitry coupled to said virtual power supply rail and said control circuitry and configured to sense said virtual rail voltage and to generate a sensed voltage signal for supply to said control circuitry; wherein said control circuitry is configured to operate in an adaptive retention mode when said at least one operational mode transistor is in a high impedance state to vary said control voltage supplied to said at least one operational mode transistor in dependence upon said sensed voltage signal such that: