Capacitive load driving device
AssigneeFujitsu Limited
InventorYutaka Takita
Life of this patent
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Abstract
A capacitive load driving device applies a multi-level voltage to a capacitive load to drive the capacitive load. In the capacitive load driving device, a voltage control signal generator unit generates a voltage control signal. A voltage amplifier unit amplifies a voltage of the voltage control signal. A current amplifier unit amplifies a current of an output of the voltage amplifier unit to perform charging of the capacitive load. A falling control signal generator unit generates a falling pulse having a predetermined pulse width when a width of falling of the voltage control signal exceeds a predetermined value. A switching unit performs discharging of the capacitive load in response to the falling pulse received.
Claims2
A capacitive load driving device which applies a multi-level voltage to a capacitive load to drive the capacitive load, comprising:
- a voltage control signal generator unit to generate a voltage control signal;
- a voltage amplifier unit to amplify a voltage of the voltage control signal;
- a current amplifier unit to amplify a current of an output of the voltage amplifier unit to perform charging of the capacitive load;
- a falling control signal generator unit to generate a falling pulse with a predetermined pulse width when a width of falling of the voltage control signal exceeds a predetermined value;
- and
- a switching unit to perform discharging of the capacitive load in response to the falling pulse received from the falling control signal generator unit,
- wherein the falling control signal generator unit comprises:
- table unit to access a table with a digital value of a previously supplied voltage control signal and a digital value of a currently supplied voltage control signal, and read a specific value from the table when a width of falling from the previously supplied voltage control signal value to the currently supplied voltage control signal value exceeds a predetermined value;
- and
- a pulse generator unit to generate a falling pulse when the specific value is read from the table.
Dependencies are inferred from the claim text.