Light source driving apparatus having a snubber to prevent voltage and current spikes, display apparatus and driving method thereof

A display apparatus comprising:

• a display which displays an image;
• and
• a driver which drives the display and comprises a tapped-inductor boost converter (TIBC) circuit,
• the TIBC circuit comprising:
• a switching unit which is turned on and off in accordance with a driving signal;
• a tapped inductor which transfers a current from a primary side to a secondary side as the switching unit is turned on and off, the tapped inductor comprising a first inductor and a second inductor coupled to the first inductor;
• a snubber provided at the secondary side of the tapped inductor, the snubber comprising a clamp capacitor and a clamp diode configured to clamp a voltage of the switching unit, a first resonance diode and a second resonance diode connected in series to each other, and a resonance capacitor connected to the secondary side of the tapped inductor at one end thereof and connected to a point between the first and second resonance diodes at the other end thereof, the resonance capacitor being configured to perform a resonance as being charged and discharged corresponding to a switching cycle of the switching unit;
• an output-side diode connected to the secondary side of the tapped inductor at one end thereof and connected to the second resonance diode at the other end thereof;
• and
• an output-side capacitor connected to the output-side diode and the second resonance diode,
• wherein the clamp capacitor is configured to have a larger capacity than the resonance capacitor.

A driving method of a light source driving apparatus with a tapped-inductor boost converter circuit comprising a switching unit turned on and off in accordance with a preset cycle, a tapped inductor transferring a current from a primary side to a secondary side as the switching unit is turned on and comprising a first inductor and a second inductor coupled to the first inductor, and a snubber provided at the secondary side of the tapped inductor and operating in a current continuity mode, the method comprising:

• turning on the switching unit in a state where a resonance capacitor of the snubber is discharged, the resonance capacitor being connected in parallel with the second inductor;
• transferring a current from the primary side of the tapped inductor to the switching unit as the switching unit is turned on;
• reversing a current in the secondary side of the tapped inductor;
• by a first resonance diode and a second resonance diode of the snubber, performing a resonance between leakage inductance of the switching unit and the resonance capacitor in order to charge the resonance capacitor;
• and
• clamping the drain voltage of the switching unit to a voltage of a clamp capacitor,
• wherein the resonance capacitor at one end thereof is connected to the secondary side of the tapped inductor and at the other end thereof, connected to a point between the first and second resonance diodes,
• wherein the tapped-inductor boost converter circuit further comprises an output-side diode connected to the secondary side of the tapped inductor at one end thereof and connected to the second resonance diode at the other end thereof, and an output-side capacitor connected to the output-side diode and the second resonance diode, and
• wherein the clamp capacitor is configured to have a larger capacity than the resonance capacitor.

A tapped-inductor boost converter (TIBC) circuit comprising:

• a switching unit configured to be turned on and off in accordance with a driving signal;
• a tapped inductor configured to transfer a current from a primary side to a secondary side as the switching unit is turned on and off, the tapped inductor comprising a first inductor and a second inductor coupled to the first inductor;
• a snubber provided at the secondary side of the tapped inductor, the snubber comprising a clamp capacitor configured to clamp a voltage of the switching unit, a first and a second resonance diode connected to each other, and a resonance capacitor connected to the secondary side of the tapped inductor at one end thereof and connected to a point between the first and second resonance diodes at the other end thereof, the resonance capacitor configured to perform a resonance as being charged and discharged corresponding to a switching cycle of the switching unit;
• and
• an output-side diode connected to the secondary side of the tapped inductor at one end thereof and connected to the second resonance diode at the other end thereof,
• wherein the clamp capacitor is configured to have a larger capacity than the resonance capacitor.