Positive/negative high voltage charge pump system
US6023188A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 15, 1999 |
| Grant date | Feb 8, 2000 |
| Priority date | — |
| Expiry date | Jan 15, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/073
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A two-phase high voltage generator circuit is electronically reconfigurable to output positive (V.sub.Pp) or negative (V.sub.Pn) high voltage, depending upon whether positive or negative mode operation is selected. The circuit includes a plurality of series-connected charge multiplier stages that each comprises a MOS transistor and a charging capacitor. Collectively the stages define an anode node and a cathode node. One of two non-overlapping phase signals is coupled to the free end of each charging capacitor such that adjacent charging capacitors are driven by different phases. First and second two-way multiplexers (MUX1, MUX2) control voltages presented to the anode and cathode nodes, to determine whether circuit operation is positive or negative mode. The MOS devices may be PMOS or NMOS, and preferably Vt-cancellation is provided for each charging stage. A precharge/discharge circuit preferably is coupled to each voltage node including the load capacitor. Further, substrate-well protection is provided such that the MOS devices are less prone to exhibit voltage breakdown or substrate to source/drain current flow.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.