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:
May. 23, 1989
Filed:
Feb. 03, 1988
Gerald A Miller, Hudson, NH (US);
Analog Devices, Incorporated, Norwood, MA (US);
Abstract
A sample/hold amplifier comprising two transconductance stages with their inverting input terminals connected together. In sample mode, the input signal is connected to the non-inverting input of the first stage, and a hold capacitor is connected to the non-inverting input terminal of the second stage and driven by the amplifier output through a feedback circuit which forces the hold capacitor voltage to track the input signal. Upon switchover to hold mold, the roles of the two transconductance stages are interchanged: The non-inverting input terminal of the first stage is connected through a feedback circuit to the amplifier output, and the second stage receives as an input signal the voltage of the hold capacitor, which now is disconnected from the amplifier output. The net offset voltage developed on the hold capacitor is the difference between the respective offsets of the two transconductance stages. This net offset voltage is compensated for by an equal and opposite voltage in hold mode, due to the interchange of roles of the two transconductance stages.