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. 05, 2000
Filed:
May. 20, 1999
David Kwong, Fremont, CA (US);
Alex Chi-Ming Hui, Los Altos, CA (US);
Pericom Semiconductor Corp., San Jose, CA (US);
Abstract
A voltage translator uses an n-channel translator transistor to translate an input voltage at its drain to an output voltage at its source. The gate and substrate of the translator transistor are each biased by charge pumps. A reference transistor is also biased by the charge pumps. A reference input voltage is translated to a reference output voltage by the reference transistor. The reference output voltage is compared to a target output voltage by comparators. When the reference output voltage is below the target, the gate charge pump is turned on, raising the gate voltage to both the reference and translator transistors. The higher gate voltage VGATE raises the output voltage VOUT since VOUT=VGATE-VT for a transistor in saturation. When the reference output voltage is above the target, the substrate charge pump is turned on, pulling the substrate bias voltage below ground. The body effect causes the transistor threshold VT to increase as the substrate is pumped. The higher threshold lowers the output voltage. Once the reference output voltage reaches the target, the charge pumps turn off. The input voltage can toggle high and low since the reference transistor sets the gate and substrate voltages.