Dynamic power supply switching for clocking signals
US8829944B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Sep 30, 2013 |
| Grant date | Sep 9, 2014 |
| Priority date | — |
| Expiry date | Sep 30, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0018
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In an integrated circuit having input circuitry whose positive and/or negative input signals are gated by one or more clocked input switches, the switch clock signal CLK_SW used to clock the input switch(es) is automatically generated based on the higher of the IC's power supply voltage VDD and the positive input signal voltage Vplus. In one embodiment, a clock level shifter shifts an input clock signal CLK_VDD from the VDD voltage domain to generate a level-shifted clock signal CLK_VPLUS in the Vplus voltage domain. Based on a control signal VSEL, a clock selector selects either the input clock signal or the level-shifted clock signal to be the switch clock signal. An over-voltage detector generates both the logic state and the voltage domain of the control signal based on the higher of VDD and Vplus, such that the input switches are appropriately clocked even during over-voltage conditions in which Vplus>VDD.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.