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:
Jun. 12, 2001
Filed:
Nov. 12, 1999
Luca Fontanella, Venice, IT;
Giovanni Frattini, Travaco, IT;
Giorgio Pedrazzini, Pavia, IT;
Giulio Ricotti, Broni, IT;
STMicroelectronics S.r.l., Agrate Brianza, IT;
Abstract
A driver circuit for controlling a piezoelectric actuator in a charge mode includes an amplifier having a first input terminal for receiving a control voltage, a second input terminal, and a main final stage with a main output terminal connected to the piezoelectric actuator. The amplifier also includes an additional final stage with an additional output terminal connected to the second input terminal. The main final stage and the additional final stage are connected in parallel with one another so that a current which passes through the main output terminal is proportional in accordance with a predefined factor to a current which passes through the additional output terminal. The driver circuit includes a device having a constant capacitance connected to the second input terminal so that an electrical charge transferred to the piezoelectric actuator is correlated with the control voltage in accordance with the predefined factor and the capacitance.