The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 14, 1998
Filed:
Aug. 23, 1996
Motorola, Inc., Schaumburg, IL (US);
Abstract
A non-linear charge pump (1120) provides various voltages for use in a nonvolatile memory (400) and operates at low power supply voltages. The non-linear charge pump (1120) includes at least two non-linear voltage doubling stages (1132, 1134), which allows a capacitor formed with relatively thin gate oxide in a first stage (1132) to be made larger than a capacitor formed using relatively thick gate oxide in a second stage (1134). An output of a last voltage doubling stage (1136) is then input to a linear stage (1150) to generate a precise voltage. Another charge pump (1140) including non-linear stages (1142, 1144) followed by a linear stage (1146) is used to generate a reference voltage for the main non-linear charge pump (1130). The nonlinear stage (1130) includes a special bulk biasing circuit to bias the bulk of a transistor (1285) on the output side of the charging circuit (1284, 1285, 1286, 1287) continuously to prevent forward biasing the parasitic drain-bulk diode.