Multiple-output dc-dc converter

• Main Author: SLUIJS FERDINAND JACOB
• Format: Patent
• Language: English
• Published: 20.11.2007
• Subjects: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC,OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWERSUPPLY SYSTEMS; CONTROL OR REGULATION THEREOF; CONTROLLING; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUTPOWER; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION; PHYSICS; REGULATING; SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES

The multiple-output DC-DC converter comprises an inductor (L) and a main switch (S 0 ) which periodically couples a DC-input voltage (Vin) to the inductor (L). Each one of a multitude of loads (L 1, L 2 , L 3 ) is coupled to the inductor (L) via one of a multitude of output switches (S 1, S 2, S 3 ). One of a multitude of output voltages (V 1, V 2, V 3 ) is present across each of the loads (L 1, L 2 , L 3 ). A controller (CO) controls the main switch (S 0 ) and the output switches (S 1, S 2, S 3 ) in sequences (SE) of cycles (CY). Each one of the cycles (CY 1, CY 2, CY 3 ) contains an on-phase of the main switch (S 0 ) followed by an on-phase of one of the multitude of output switches (S 1, S 2, S 3 ). The cycles (CY 1, CY 2, CY 3 ) have either a predetermined first (minimum) duty cycle (D 1 ) or a second (maximum) duty cycle (D 2 ) which is larger than the first duty cycle (D 1 ). The controller (CO) comprises a multitude of comparators ( 10, 11, 12 ) which each compare one of the multitude of output voltages (V 1, V 2, V 3 ) with an associated one of a multitude of reference voltages (VR 1, VR 2, VR 3 ). The controller (CO) further checks whether the number of the multitude of output voltages (V 1, V 2, V 3 ) which have a value above their associated reference voltage (VR 1, VR 2, VR 3 ) is larger than, smaller than, or equal to the number of the multitude of output voltages (V 1, V 2, V 3 ) which have a value below their associated reference voltage (VR 1, VR 2, VR 3 ). The duty cycles are selected such that the number of cycles (CY 1, CY 2, CY 3 ) with the minimal duty cycle (D 1 ) are larger than, smaller than, or equal to the number of cycles with the maximum duty cycle (D 2 ), respectively.