Driving device
Output signal waveform having high input signal reproducibility is outputted from inductive load or the like. Output signals V 1 a and V 1 b obtained by feeding back an output signal Vp-n 1 at output terminals 50 and 51 across load L 1 to input terminals 9 a and 9 b are compared with an input signal Vin to detect an error between signals; a first error suppression signal Vout 1 is produced such that the detected error between the signals is suppressed; inclination of first error suppression signal Vout 1 is detected, and a second error suppression signal Vout 2 is produced such that inclination error to input signal Vin is suppressed based on the detected inclination signal; and the ratio between the period that electric power is supplied to the load L 1 and the period that electric power is not supplied to the load L 1 is modified according to the error of the error suppression signal.
1. A driving device for controlling electric power to load based on switching elements, the device comprising:
a driving means having a switching circuit including a plurality of switching elements connected to the load;
a first feedback means for feeding back an output signal at an output terminal of the load to an input terminal to which an input signal is inputted;
an error suppression means, connected to the input terminal, for comparing the output signal fed back via the first feedback means with the input signal to detect an error between signals, and producing an error suppression signal that the error is corrected;
a control means for controlling switching of operation of the plurality of the switching elements in the driving means based on the error suppression signal; and
a second feedback means for detecting a inclination component of a signal outputted from the error suppression means, and feeding back the inclination component to an input terminal of the error suppression means,
wherein the error suppression means compares the input signal with a combination signal that the inclination component fed back via the second feedback means is added to the output signal fed back via the first feedback means to detect an error between signals, and produces an error suppression signal in which the error is corrected.
2. The driving device according to claim 1 , wherein the second feedback means is a differentiation circuit that differentiates a signal outputted from the error suppression means.
3. The driving device according to claim 1 , wherein the second feedback means is a high-pass filter or a band pass filter.
4. The driving device according to claim 1 , wherein the load is capacitive load or inductive load.
5. The driving device according to claim 1 , wherein the load is a piezoelectric speaker or a dynamic speaker.
6. An information apparatus comprising:
a driving device according to any one of claims 1 to 5 ,
controlling electric power to load based on switching elements;
an information processing portion, having a communication function and an information processing function, for controlling the driving device; and
a battery for supplying electric power to the driving device and the information processing portion.