High-voltage CMOS level shifter
US5821800A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 11, 1997 |
| Grant date | Oct 13, 1998 |
| Priority date | — |
| Expiry date | Feb 11, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K3/356113
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A high-voltage level shifter includes one or more complementary NMOS/PMOS series intermediate transistor pairs to divide the high-voltage supply range into two or more sub-ranges. The level shifter has a differential structure with complementary NMOS input transistors. Cross-coupled PMOS output transistors provide complementary outputs. The complementary NMOS/PMOS series intermediate transistor pairs separate the NMOS input transistor drains from the PMOS output transistor drains. In order to divide the high voltage range into h subranges, h-1 complementary NMOS/PMOS series intermediate transistor pairs are used each being biased by monotonically increasing fixed intermediate voltages. In a shared-bias embodiment, each complementary NMOS/PMOS series intermediate transistor pair is biased by a single corresponding intermediate voltage. In a split-bias embodiment, each complementary NMOS/PMOS series intermediate transistor pair is biased by a corresponding NMOS bias voltage and a corresponding PMOS bias voltage, in which the NMOS bias voltage is higher than the PMOS bias voltage by the sum or the NMOS threshold voltage and the PMOS threshold voltage. In another aspect, the N-wells of…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.