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:
Sep. 12, 1995
Filed:
Apr. 01, 1994
Tim M Coffman, Sugarland, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A level shifter circuit 150 for selecting different voltage levels for programming memory cells 10 is provided. The level shifter 150 has an input 152 connected to a control circuitry and an output 154 connected to memory cells 10. The level shifter 150 is connected to two voltage sources: a high voltage source 166 and a low voltage source 164. The level shifter 150 has an isolation transistor 156 to buffer the input control circuitry from the higher voltage in the level shifter 150. Depending on the input control signal, either a first switching transistor 158 will select the low voltage source 164 for output or a second switching transistor 162 will select the high voltage source 166 for output. A pull-up transistor 162 is used to maintain the state of the switching transistors 158, 160 when the voltage sources 164, 166 ramp up. A voltage limiting transistor 170 reduces the voltage potential (breakdown voltage) across the drain and source terminals of the pull-up transistor 162.