US Patent No. 9,197,124

METHOD AND APPARATUS TO REDUCE OVERCURRENT DURING THE STARTUP OF A SWITCHING REGULATOR


Patent No. 9,197,124
Issue Date November 24, 2015
Title Method And Apparatus To Reduce Overcurrent During The Startup Of A Switching Regulator
Inventorship Biing Long Shu, Siglap (SG)
Jinho Choi, Saratoga, CA (US)
Jye Sheng Hong, Singapore (SG)
Ravishanker Krishnamoorthy, Singapore (SG)
Assignee MARVELL WORLD TRADE LTD., St. Michael (BB)

Claim of US Patent No. 9,197,124

1. A power supply apparatus, comprising:
an inductor configured to store and discharge energy;
a pulse generator configured to generate a plurality of pulses; and
a circuit configured to determine a plurality of overcurrent detect signals for the plurality of pulses, respectively, generate
a charging pulse for each of the plurality of pulses when the respective overcurrent detect signal has a first value, skip
generation of the respective charging pulse for each of the plurality of pulses when the respective overcurrent detect signal
has a second value, and charge the inductor using the generated charging pulses,

wherein the second value indicates a detection or prediction of an overcurrent associated with the inductor, and the first
value indicates a detection or prediction of an absence of the overcurrent,

wherein the circuit is configured to skip generation of the respective charging pulse for each of the plurality of pulses
when the circuit is in a startup period, wherein the circuit being in the startup period is determined using an output voltage
of the power supply apparatus, a resistor-capacitor (RC) circuit, or a cycle count of the charging pulses, and

wherein the output voltage is compared to a threshold voltage Vo, and

wherein Vin is a voltage applied to the inductor during charging, Ton is a duration of the skipped charging pulse, N is a
turns ratio of a primary winding of the inductor to a secondary winding of the inductor, and Tcyc is an interval between charging
pulses.