Driver for piezoelectric actuator
First Claim
1. A driver including a boost converter, a pulse width modulator controlling the boost converter, and an amplifier powered by the boost converter, characterized in thatthe pulse width modulator and the amplifier are packaged as a single semiconductor device.
3 Assignments
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Accused Products
Abstract
A driver for a piezoelectric actuator includes a pulse width modulator and an output amplifier packaged as a single semiconductor device, preferably on a single semiconductor die. The driver includes a first boost converter that supplies power to the output amplifier, which preferably has programmable gain. A second amplifier, for driving the gate of a switching transistor in the first boost converter, is powered by a second boost converter. The piezoelectric actuator provides tactile feedback for the keyboard or the display in a battery operated electronic device.
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Citations
19 Claims
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1. A driver including a boost converter, a pulse width modulator controlling the boost converter, and an amplifier powered by the boost converter, characterized in that
the pulse width modulator and the amplifier are packaged as a single semiconductor device.
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7. In a battery operated, electronic device having a display and a keypad, at least one of which includes a piezoelectric actuator for tactile feedback, a driver coupled to said piezoelectric actuator and including a first boost converter, a pulse width modulator controlling the boost converter, and an output amplifier powered by the boost converter, characterized in that the driver further includes
a second amplifier coupling said pulse width modulator to said boost converter and a second boost converter for powering said second amplifier.
Specification