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:
Jan. 23, 2001
Filed:
Nov. 19, 1998
Roy Clifton Jones, III, Dallas, TX (US);
Wayne T. Chen, Plano, TX (US);
David Cotton, Plano, TX (US);
Baoson Nguyen, Plano, TX (US);
Texas Instruments Incorporated, Dallas, TX (US);
Abstract
A charge pump uses switching transistors including a PMOS transistor (P,), a first transistor (N,), and a second transistor (N,) instead of diodes (D,, D,) to control the transfer of charge from a pump capacitor (,) to a storage capacitor (,). The voltage (,) at the storage capacitor (,) is applied to a level shifter (,) and to the source of the PMOS transistor (P,) which, in turn, biases the first transistor (N,) during low state of an oscillating waveform (,B). A supply rail (,) charges the pump capacitor (,) when the first transistor (N,) is in its active region during the low state of the oscillating waveform (,B) and turns OFF during the high state of the waveform (,B) causing the charge on the pump capacitor (,) to be transferred to the storage capacitor (,). The level shifter (,) is used to synchronize the oscillating waveform (,B) so that no charge is lost from the pump capacitor (,) back to the supply and minimal charge is conducted through a parasitic diode (,).