Drive device
AssigneeAsahi Kasei Microdevices Corporation
InventorsToshio Kaiho, Hidenobu Takeshita
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Abstract
There is provided a drive device capable of driving a capacitive load with efficiency and with low power consumption while keeping quality input reproducibility for output signal. A switching drive circuit 10f repeatedly performs operations in the order of VCP charging phase PH_VCP_CH, VCP discharging phase PH_VCP_dCH, VCN charging phase PH_VCN_CH, and VCN discharging phase PH_VCN_dCH. A drive circuit switching amplifier 10 allows a charging phase per cycle for an input signal VIN that is a reference for operation to be either a phase in which the slope of the input signal VIN is positive from a reference voltage REFL or greater until a maximum voltage, or a phase in which the slope of the input signal VIN is negative from a reference voltage REFH or less until a minimum voltage.
Claims17
A drive device for performing a pulse modulation of an input signal and outputting an output signal for driving a capacitive load;
- the drive device comprising:
- switching driver for including a charging switching element for charging the capacitive load and a short-circuiting switching element for short-circuiting between both terminals of the capacitive load to discharge the capacitive load, and operating the charging switching element and the short-circuiting switching element to output the output signal;
- and
- driving controller for controlling the switching driver based on the pulse-modulated input signal so as to repeatedly perform a charging phase that alternately repeats a phase charging the capacitive load and a phase not charging the capacitive load, and a discharging phase that alternately repeats a phase discharging the capacitive load and a phase not discharging the capacitive load,
- wherein the driving controller controls so as to change over from the charging phase to the discharging phase or from the discharging phase to the charging phase when a slope of the input signal changes.
A driving method of performing a pulse modulation of an input signal and driving a capacitive load, the driving method comprising:
- repeatedly performing a charging phase that alternately repeats a phase charging the capacitive load and a phase not charging the capacitive load, and a discharging phase that alternately repeats a phase discharging the capacitive load and a phase not discharging the capacitive load, based on the input signal, and
- changing over from the charging phase to the discharging phase or from the discharging phase to the charging phase, when a slope of the input signal changes.
Dependencies are inferred from the claim text.