Abstract: An LED driving device (30) includes: a plurality of LED terminals (LED1 to LED6 terminals) to have connected to them the cathodes of LEDs (41 to 46) in a plurality of channels; a lowest voltage input terminal (MINSELIN); a lowest voltage output terminal (MINSELOUT); and a selector (10). When the lowest voltage input terminal is used, the selector selects the lowest among the voltages at the plurality of LED terminals and the voltage at the lowest voltage input terminal, to output the lowest voltage from the lowest voltage output terminal; when the lowest voltage input terminal is not used, the selector selects the lowest among the voltages at the plurality of LED terminals, to output the lowest voltage from the lowest voltage output terminal.

Abstract: The present disclosure provides a light emitting element driving device. The light emitting element driving device includes a constant current circuit and a current detection unit. The constant current circuit includes: a first transistor including a first end, a second end and a control end connected to an external terminal; a current setting resistance connected to the second end of the first transistor; and a drive amplifier including a first input end connected to a first node to which the first transistor and the current setting resistance are connected, a second input end to which a current set voltage is applied, and an output end connected to the control end of the first transistor. The current detection unit generates a current detection signal based on a feedback voltage generated in the first node.

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

Abstract: The present disclosure provides a light emitting element driving device. The light emitting element driving device includes a constant current circuit and a current detection unit. The constant current circuit includes: a first transistor including a first end, a second end and a control end connected to an external terminal; a current setting resistance connected to the second end of the first transistor; and a drive amplifier including a first input end connected to a first node to which the first transistor and the current setting resistance are connected, a second input end to which a current set voltage is applied, and an output end connected to the control end of the first transistor. The current detection unit generates a current detection signal based on a feedback voltage generated in the first node.

Abstract: In an LED driving device, a DC-DC controller performs control such that the voltage at an LED terminal remains equal to a reference voltage, and a reference voltage generator generates the reference voltage such that it decreases as the set value of the LED current set by an LED current setter decreases.

Abstract: This LED driving device comprises: a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED, wherein the current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal, and the DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage, and a pulse addition control unit which performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

Abstract: An LED driving device includes a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED. The current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal. The DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage. A pulse addition control unit performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

Abstract: An LED driving device includes a DC/DC controller which controls an output stage for supplying an output voltage to an LED; and a current driver which generates an output current of the LED. The current driver performs PWM dimming by turning on the output current in accordance with an LED-current-on period of a PWM dimming signal and turning off the output current in accordance with an LED-current-off period of the PWM dimming signal. The DC/DC controller includes a feedback control unit which performs feedback control for outputting a switching pulse to the output stage so as to make a cathode voltage of the LED equal to a reference voltage. A pulse addition control unit performs pulse addition control for adding a predetermined pulse number of additional switching pulses at a time of switching between the LED-current-on period and the LED-current-off period.

Abstract: An LED drive circuit drives an LED module. The LED module has a light-emitting diode, and an identification unit having characteristic information relating to light-emitting characteristics of the light-emitting diode. The LED drive circuit includes a detection unit and a drive circuit. The detection unit is provided for detecting characteristic information, and generates a detection signal that corresponds to the characteristic information. The drive circuit generates drive current by a drive signal supplied according to the characteristic information based on the detection signal, and supplies the drive current to drive the light-emitting diode.

Abstract: A light-emitting element driving semiconductor integrated circuit constitutes at least part of a light-emitting element driving device that is configured to drive a first and a second light source when the first light source is not short-circuited and drive the second light source when the first light source is short-circuited and that includes an output capacitor. The light-emitting element driving semiconductor integrated circuit has a controller configured to control the resistance value of a variable resistor connected in series with the first and second light sources according to the voltage across a resistor connected in series with the first and second light sources.

Abstract: An LED drive circuit drives an LED module. The LED module has a light-emitting diode, and an identification unit having characteristic information relating to light-emitting characteristics of the light-emitting diode. The LED drive circuit includes a detection unit and a drive circuit. The detection unit is provided for detecting characteristic information, and generates a detection signal that corresponds to the characteristic information. The drive circuit generates drive current by a drive signal supplied according to the characteristic information based on the detection signal, and supplies the drive current to drive the light-emitting diode.

Abstract: A light emitting element driving apparatus includes the following: current source; error amplifier generating error signal based on comparison of a first reference voltage with the highest voltage among total forward drop voltages of element arrays or feedback voltage corresponding to a drive voltage; first and second switches for ON/OFF control to apply the feedback voltage to first and second input terminals of the error amplifier respectively; slope voltage generating circuit; PWM comparator generating a pulse modulation signal; drive amplifier controlled by the pulse modulation signal and drives a switching element supplying the drive voltage to the element arrays; PWM width detector that outputs a pulse width detection signal having different levels between when the pulse width is less than predetermined threshold value and when equal to or greater than the threshold value, and switches ON/OFF of the first and second switches based on the pulse width detection signal.

Abstract: A light emitting element driving apparatus includes the following: current source; error amplifier generating error signal based on comparison of a first reference voltage with the highest voltage among total forward drop voltages of element arrays or feedback voltage corresponding to a drive voltage; first and second switches for ON/OFF control to apply the feedback voltage to first and second input terminals of the error amplifier respectively; slope voltage generating circuit; PWM comparator generating a pulse modulation signal; drive amplifier controlled by the pulse modulation signal and drives a switching element supplying the drive voltage to the element arrays; PWM width detector that outputs a pulse width detection signal having different levels between when the pulse width is less than predetermined threshold value and when equal to or greater than the threshold value, and switches ON/OFF of the first and second switches based on the pulse width detection signal.

Abstract: An oscillation circuit for generating a clock signal of a switching power supply circuit is provided. The oscillation circuit includes a circuit configured to perform frequency spreading control of the clock signal in synchronization with an output operation control signal for periodically turning on/off an output operation of the switching power supply circuit.

Abstract: A light-emitting element driving semiconductor integrated circuit constitutes at least part of a light-emitting element driving device that is configured to drive a first and a second light source when the first light source is not short-circuited and drive the second light source when the first light source is short-circuited and that includes an output capacitor. The light-emitting element driving semiconductor integrated circuit has a controller configured to control the resistance value of a variable resistor connected in series with the first and second light sources according to the voltage across a resistor connected in series with the first and second light sources.

Abstract: An oscillation circuit for generating a clock signal of a switching power supply circuit is provided. The oscillation circuit includes a circuit configured to perform frequency spreading control of the clock signal in synchronization with an output operation control signal for periodically turning on/off an output operation of the switching power supply circuit.

Abstract: An LED short-circuit detection circuit produces an LED short-circuit detection signal by monitoring an LEDC terminal voltage (a first voltage obtained at a chip-to-chip node in a row of LED chips, or a divided voltage thereof) and an LEDR terminal voltage (a second voltage obtained by dividing the end-to-end voltage of the row of LED chips).

Abstract: An oscillation circuit includes: a ramp voltage generating unit configured to generate a ramp voltage; and a clock signal generating unit configured to generate a clock signal. The clock signal generating unit includes: a bias unit configured to apply one of the ramp voltage and a fixed voltage, as a bias voltage, to a resistor; and an oscillator configured to determine an oscillation frequency of the clock signal in response to a bias current flowing through the resistor.

Abstract: An oscillation circuit includes: a ramp voltage generating unit configured to generate a ramp voltage; and a clock signal generating unit configured to generate a clock signal. The clock signal generating unit includes: a bias unit configured to apply one of the ramp voltage and a fixed voltage, as a bias voltage, to a resistor; and an oscillator configured to determine an oscillation frequency of the clock signal in response to a bias current flowing through the resistor.