Abstract: A drive circuit (100) includes an operational amplifier (OP1) that compares a voltage applied to an inverting input terminal with a reference voltage applied to a non-inverting input terminal, a MOS transistor (M1) that has an output connected to the inverting input terminal of the operational amplifier (OP1) and supplies a current to a load (3) depending on a comparison result of the operational amplifier (OP1), and a switch (SW1) that switches, based on a control signal, between outputting the comparison result of the operational amplifier (OP1) to the MOS transistor (M1) and outputting a predetermined voltage to the MOS transistor (M1) to turn off the MOS transistor (M1).

Abstract: In the power supply apparatus which performs voltage conversion of an input voltage (Vbat), with a predetermined set voltage as a target value, and outputs the converted voltage, a boost ratio setting unit sets a boost ratio (XCP) of the charge pump circuit based on the input voltage (Vbat) and a predetermined set voltage. A voltage adjustment unit is a regulator circuit, and adjusts voltage (Vx) so that output voltage (Vout) of the charge pump circuit approaches the set voltage. An output voltage setting unit generates a predetermined set voltage as a digital value (Dset). An A/D converter performs analog-digital conversion of the input voltage (Vbat). The boost ratio setting unit sets the boost ratio based on a result of comparing an input voltage (Ddet) that has undergone analog-digital conversion, and the set voltage (Dset).

Abstract: An LED driver 5 includes current sources (52R, 52G, 52B) for generating drive current of LED (4R, 4G, 4B); and a black insert control section (54) for generating a black insert signal (BK) for determining a black insert period in one frame from a frame synchronizing signal (such as vertical synchronizing signal VS). The current sources (52R, 52G, 52B) stop current supply to the LEDs (4R, 4G, 4B) during the black insert period according to the black insert signal (BK). With this configuration, it is possible to enhance the moving image visibility of a liquid crystal display device without increasing the load on display control means or significantly lowering the light source brightness.

Abstract: In a constant current circuit that supplies a constant current Ic to a circuit connected to a current output terminal, the first transistor M1 is disposed on a current path of the constant current Ic. The second transistor and the first transistor have commonly connected gate terminals which are control terminals. The first current-voltage converting unit converts the current Im2 flowing through the second transistor into a voltage. A constant current source generates a reference current Iref. The second current-voltage converting unit converts the reference current into a voltage. Into the first error amplifier, voltages Vx1, Vx2 are input, so as to adjust the gate voltage of the first and second transistors. A voltage adjusting unit adjusts the voltage at the gate terminal of the third transistor so that the voltage at one end of the second transistor will be approximated to a predetermined reference voltage.

Abstract: A drive circuit (100) includes an operational amplifier (OP1) that compares a voltage applied to an inverting input terminal with a reference voltage applied to a non-inverting input terminal, a MOS transistor (M1) that has an output connected to the inverting input terminal of the operational amplifier (OP1) and supplies a current to a load (3) depending on a comparison result of the operational amplifier (OP1), and a switch (SW1) that switches, based on a control signal, between outputting the comparison result of the operational amplifier (OP1) to the MOS transistor (M1) and outputting a predetermined voltage to the MOS transistor (M1) to turn off the MOS transistor (M1).

Abstract: A drive circuit (100) includes an operational amplifier (OP1) that compares a voltage applied to an inverting input terminal with a reference voltage applied to a non-inverting input terminal, a MOS transistor (M1) that has an output connected to the inverting input terminal of the operational amplifier (OP1) and supplies a current to a load (3) depending on a comparison result of the operational amplifier (OP1), and a switch (SW1) that switches, based on a control signal, between outputting the comparison result of the operational amplifier (OP1) to the MOS transistor (M1) and outputting a predetermined voltage to the MOS transistor (M1) to turn off the MOS transistor (M1).

Abstract: The backlight device of the present invention is provided with a light emitting unit emitting light of N (N?2) colors and a light emission control unit making the light emitting unit emit light of one of the N colors for each field. The light emission control unit varying, from one flame to the next, the order of light emission colors within each frame is designed for use in the backlight device and an image display device incorporating such a backlight device. Thus, it is possible to realize the backlight device and the image display device incorporating such a backlight device in which, irrespective of an image recognition period (a period in which an image is recognized during the movement of the viewpoint on a display), the continuous recognition of light of the same color is prevented during the movement of the viewpoint on a display.

Abstract: In a constant current circuit that supplies a constant current Ic to a circuit connected to a current output terminal, the first transistor M1 is disposed on a current path of the constant current Ic. The second transistor and the first transistor have commonly connected gate terminals which are control terminals. The first current-voltage converting unit converts the current Im2 flowing through the second transistor into a voltage. A constant current source generates a reference current Iref. The second current-voltage converting unit converts the reference current into a voltage. Into the first error amplifier, voltages Vx1, Vx2 are input, so as to adjust the gate voltage of the first and second transistors. A voltage adjusting unit adjusts the voltage at the gate terminal of the third transistor so that the voltage at one end of the second transistor will be approximated to a predetermined reference voltage.

Abstract: In the power supply apparatus which performs voltage conversion of an input voltage (Vbat), with a predetermined set voltage as a target value, and outputs the converted voltage, a boost ratio setting unit sets a boost ratio (XCP) of the charge pump circuit based on the input voltage (Vbat) and a predetermined set voltage. A voltage adjustment unit is a regulator circuit, and adjusts voltage (Vx) so that output voltage (Vout) of the charge pump circuit approaches the set voltage. An output voltage setting unit generates a predetermined set voltage as a digital value (Dset). An A/D converter performs analog-digital conversion of the input voltage (Vbat). The boost ratio setting unit sets the boost ratio based on a result of comparing an input voltage (Ddet) that has undergone analog-digital conversion, and the set voltage (Dset).

Abstract: A drive circuit (100) includes an operational amplifier (OP1) that compares a voltage applied to an inverting input terminal with a reference voltage applied to a non-inverting input terminal, a MOS transistor (M1) that has an output connected to the inverting input terminal of the operational amplifier (OP1) and supplies a current to a load (3) depending on a comparison result of the operational amplifier (OP1), and a switch (SW1) that switches, based on a control signal, between outputting the comparison result of the operational amplifier (OP1) to the MOS transistor (M1) and outputting a predetermined voltage to the MOS transistor (M1) to turn off the MOS transistor (M1).

Abstract: An LED driver 5 includes current sources (52R, 52G, 52B) for generating drive current of LED (4R, 4G, 4B); and a black insert control section (54) for generating a black insert signal (BK) for determining a black insert period in one frame from a frame synchronizing signal (such as vertical synchronizing signal VS). The current sources (52R, 52G, 52B) stop current supply to the LEDs (4R, 4G, 4B) during the black insert period according to the black insert signal (BK). With this configuration, it is possible to enhance the moving image visibility of a liquid crystal display device without increasing the load on display control means or significantly lowering the light source brightness.

Abstract: An electronic circuit has a voltage selection and output circuit, e.g. digital-to-analog converter (DAC), and a switched capacitor filter (SCF), in which operational conditions of the input side switches of the SCF are incorporated in the selection conditions for selecting respective multiple selection switches of the voltage selection and output circuit. This arrangement permits the selection switches to serve as the input side switches, thereby reducing in number serial switches such as MOS transistors in the circuit, and hence reducing the on-resistances of the serial switches, while preventing the clock feed-through thereof from increasing and suppressing output errors due to the linearity error of the buffer amplifier involved.

Abstract: Source potentials of n output transistors are fixed by common fixed voltage, and sources are connected to a current output terminal. A drain and a gate of an input transistor are commonly connected to the drains and the gates of the output transistors respectively. A first current-to-voltage conversion unit is connected onto the drain side of the input transistor to convert current Im2 flowing through the input transistor into voltage Vx1. A second current-to-voltage conversion unit converts reference current Iref into voltage Vx2. The voltages Vx1 and Vx2 are input to a first error amplifier, and the first error amplifier adjusts gate voltages of the input transistor and output transistors. n switches are provided on a path through which output of the first error amplifier reaches the gate of the output transistor. A control unit controls on/off of the switch according to a digital signal.

Abstract: In a balanced output circuit, an input signal inputted thereto is provided as a first output signal thereof on one hand, and on the other hand the input signal is inputted to an inverting amplification circuit and is compared with a comparison voltage before the signal is outputted as a second output signal. Based on the comparison of the first and second output signals, the comparison voltage is controlled by a charging voltage of a capacitor such that the DC voltage of the second output signal is equalized to that of the first output signal. Thus, the DC offset voltage between the first output signal (non-inverted output signal) and the second output signal (inverted output signal) can be properly annihilated by a simple circuit.

Abstract: Source potentials of n output transistors are fixed by common fixed voltage, and sources are connected to a current output terminal. A drain and a gate of an input transistor are commonly connected to the drains and the gates of the output transistors respectively. A first current-to-voltage conversion unit is connected onto the drain side of the input transistor to convert current Im2 flowing through the input transistor into voltage Vx1. A second current-to-voltage conversion unit converts reference current Iref into voltage Vx2. The voltages Vx1 and Vx2 are input to a first error amplifier, and the first error amplifier adjusts gate voltages of the input transistor and output transistors. n switches are provided on a path through which output of the first error amplifier reaches the gate of the output transistor. A control unit controls on/off of the switch according to a digital signal.

Abstract: In a balanced output circuit, an input signal inputted thereto is provided as a first output signal thereof on one hand, and on the other hand the input signal is inputted to an inverting amplification circuit and is compared with a comparison voltage before the signal is outputted as a second output signal. Based on the comparison of the first and second output signals, the comparison voltage is controlled by a charging voltage of a capacitor such that the DC voltage of the second output signal is equalized to that of the first output signal. Thus, the DC offset voltage between the first output signal (non-inverted output signal) and the second output signal (inverted output signal) can be properly annihilated by a simple circuit.