Abstract:
A decoder device has a reference voltage generating section for outputting first and second threshold level signals, a first comparator for comparing a stair-stepped waveform input signal and the first threshold level signal to output a comparison result, a second comparator for comparing the input signal and the second threshold level signal to output a comparison result, and a logical operation section for performing a logical operation between output signals of the first and second comparators to output a signal decoded from the input signal. A threshold level represented by the first threshold level signal intersects a riser section of one stepped waveform out of two adjacent stepped waveforms in the input signal, and a threshold level represented by the second threshold level signal intersects a riser section of the other stepped waveform out of the two adjacent stepped waveforms of the stair-stepped waveform input signal.
Abstract:
A decoder device has a reference voltage generating section for outputting first and second threshold level signals, a first comparator for comparing a stair-stepped waveform input signal and the first threshold level signal to output a comparison result, a second comparator for comparing the input signal and the second threshold level signal to output a comparison result, and a logical operation section for performing a logical operation between output signals of the first and second comparators to output a signal decoded from the input signal. A threshold level represented by the first threshold level signal intersects a riser section of one stepped waveform out of two adjacent stepped waveforms in the input signal, and a threshold level represented by the second threshold level signal intersects a riser section of the other stepped waveform out of the two adjacent stepped waveforms of the stair-stepped waveform input signal.
Abstract:
The optical sensor includes a photodiode PD1 with its anode grounded, a diode group DG1 having one end connected to a cathode of the photodiode PD1, a current source I1 having one end connected to the other end of the diode group DG1, a power supply section for applying a constant voltage to the other end of the current source I1, and a grounded-emitter NPN transistor QOUT1 having a base connected to the cathode of the photodiode PD1 and a collector connected to one end of the current source I1. The diode group DG1 is provided by n diodes D1, D2, . . . , Dn connected in series so that their forward directions are directed toward the photodiode PD1 side, and a photocurrent which flows from a connecting point between the diode group and the current source to the photodiode is converted into a voltage and outputted as a photoelectric conversion signal.
Abstract:
The optical sensor includes a photodiode PD1 with its anode grounded, a diode group DG1 having one end connected to a cathode of the photodiode PD1, a current source I1 having one end connected to the other end of the diode group DG1, a power supply section for applying a constant voltage to the other end of the current source I1, and a grounded-emitter NPN transistor QOUT1 having a base connected to the cathode of the photodiode PD1 and a collector connected to one end of the current source I1. The diode group DG1 is provided by n diodes D1, D2, . . . , Dn connected in series so that their forward directions are directed toward the photodiode PD1 side, and a photocurrent which flows from a connecting point between the diode group and the current source to the photodiode is converted into a voltage and outputted as a photoelectric conversion signal.
Abstract:
A decoder circuit of the present invention, mounted on an integrated circuit, decodes input voltage Vin supplied to a single external input terminal into three or more control outputs, and an object of the present invention is to reduce the size of a chip. The foregoing decoder circuit includes: a P-type transistor in which an emitter is connected to a power source line of high level, a base is connected to the external input terminal, and a collector is an output terminal of a first control output; and an N-type transistor in which an emitter is connected to a power source line of low level, a base is connected to the external input terminal, and a collector is an output terminal of a second control output, and decodes the control outputs to three or more sets of data by carrying out logic operations. Therefore, as compared to the case of using a comparator requiring many transistors, a constant current source, and other elements, one each transistor is required for each of the two control outputs to be generated. This facilitates size reduction of a chip.