Level shift circuit
US7768308B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 4, 2008 |
| Grant date | Aug 3, 2010 |
| Priority date | — |
| Expiry date | Jul 31, 2028 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/102
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
In a level shift circuit, the threshold voltage of N-type high-voltage transistors, to whose gates the voltage of a low-voltage supply VDD is applied, is set low. An input signal IN powered by the low-voltage supply VDD is input to the gate of an N-type transistor by way of an inverter. Therefore, even if the potentials at nodes W3 and W4 exceed the voltage of the low-voltage supply VDD, reverse current flow from the nodes W3 and W4 via parasitic diodes within the inverters into the low-voltage supply VDD is prevented. A protection circuit, composed of N-type transistor whose respective gates are fixed to the low-voltage supply VDD, is disposed between the two N-type high-voltage transistors N5, N6 and two N-type low-voltage transistors N1, N2 for receiving the complementary signals IN and XIN, thereby preventing the breakdown of those N-type complementary-signal-receiving transistors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.