Patent ID: 6728117
Filing Date: 2004-04-27
Classification: H02M

Abstract:
A switching power supply having an output voltage (VOUT) for supplying a supply current to a dynamically variable load, the switching power supply comprising:an input-current inductor coil connected in series with an input voltage source (VIN) and a power switch; an output-current inductor coil for outputting an output current at at least the output voltage (VOUT); a zero-current detector having a detector-output being activated when the output current falls to zero; a switch-driver circuit for closing and opening the power switch, the switch-driver circuit including: a flip-flop adapted to latch the activated detector-output and having a first flip-flop input connected to the detector-output, and having a flip-flop output, the flip-flop output being activated while the activated detector-output is latched; a combinatorial logic gate, having a first logic gate input connected to the flip-flop output and a second logic gate input and a logic gate output, the logic gate output being activated if the flip-flop output is activated and if the second logic gate input is not inhibited, the power switch being closed while the logic gate output is activated; a pulse generator having a pulse generator-output for outputting an OFF-pulse having a dynamically variable load-modulated pulse width that corresponds to the dynamically variable load, the pulse generator-output being connected to the second logic gate input and inhibiting the second logic gate input during the pulse-width of the load-modulated OFF-pulse.