Controllers for DC/DC converters

Claim 2

A controller for a DC/DC converter, comprising: a plurality of signal generators that generates a plurality of pulse signals having a predetermined pulse width by counting cycles of a same first oscillating signal; and a control circuit, coupled to said signal generators, that selectively activates said signal generators according to an output of said DC/DC converter to generate said pulse signals, wherein each signal generator of said signal generators, in response to a trigger signal from said control circuit, starts to count said cycles of said same first oscillating signal and generates a corresponding pulse signal of said pulse signals at a first level, and wherein said each signal generator controls said corresponding pulse signal to have a second level when a count value obtained by counting said cycles of said same first oscillating signal equals a preset end value.

Claim 3

The controller as claimed in claim 1 , wherein said predetermined pulse width is determined by multiplying said preset end value with a cycle period of said same first oscillating signal.

Claim 4

The controller as claimed in claim 1 , wherein said signal generators control said pulse signals to have substantially the same pulse width by counting a same preset number of cycles of said same first oscillating signal.

Claim 5

The controller as claimed in claim 1 , wherein said DC/DC converter comprises a plurality of switches and a plurality of inductors, and wherein each pulse signal of said pulse signals controls a pair of switches of said plurality of switches to control a current flowing through a corresponding inductor of said plurality of inductors.

Claim 6

The controller as claimed in claim 4 , wherein said current increases if said each pulse signal is in a first state, and wherein said current decreases if said each pulse signal is in a second state.

Claim 7

The controller as claimed in claim 4 , wherein said signal generators generate said pulse signals, by counting a same preset number of cycles of said same first oscillating signal, to control a plurality of currents flowing through said inductors to have substantially the same ripple amplitude.

Claim 8

The controller as claimed in claim 1 , further comprising a comparator operable for comparing said output of said DC/DC converter with a reference level.

Claim 9

The controller as claimed in claim 7 , wherein if said output is less than said reference level, then said control circuit increases said output by activating at least one signal generator of said signal generators one-by-one to generate at least one pulse signal, each of said at least one signal generator activated in response to a clock pulse of a second oscillating signal; and wherein if said output increases to said reference level, then said control circuit halts the activation of said signal generators.

Claim 10

The controller as claimed in claim 1 , wherein said control circuit comprises a shift register that is controlled by a second oscillating signal and that causes said control circuit to generate, in response to a plurality of cycles of said second oscillating signal, a plurality of trigger signals to selectively activate said signal generators.

Claim 13

The method as claimed in claim 10 , wherein said selectively activating comprises: activating at least one signal generator of said signal generators one by one to generate at least one pulse signal if said output is less than a reference level, wherein each of said at least one signal generator is activated in response to a clock pulse of a clock signal; and halting the activation of said signal generators if said output increases to said reference level.

Claim 14

A controller for a DC/DC converter, comprising: a plurality of terminals that provide a plurality of pulse signals; and control circuitry that is coupled to said terminals and selectively activates a plurality of signal generators according to an output of said DC/DC converter to generate said pulse signals, and controls each pulse signal of said pulse signals to have a predetermined pulse width by counting cycles of a same oscillating signal, wherein each signal generator of said signal generators, in response to a trigger signal, starts to count said cycles of said same first oscillating signal and generates a corresponding pulse signal of said pulse signals at a first level, and wherein said each signal generator controls said corresponding pulse signal to have a second level when a count value obtained by counting said cycles of said same first oscillating signal equals a preset end value.

Claim 15

A controller for a DC/DC converter, comprising: a plurality of terminals that provide a plurality of pulse signals; and control circuitry that is coupled to said terminals and selectively activates a plurality of signal generators according to an output of said DC/DC converter to generate said pulse signals, and controls each pulse signal of said pulse signals to have a predetermined pulse width by counting cycles of a same oscillating signal, wherein each signal generator of said signal generators, in response to a trigger signal, starts to count said cycles of said same first oscillating signal and generates a corresponding pulse signal of said pulse signals at a first level, and wherein said each signal generator controls said corresponding pulse signal to have a second level when a count value obtained by counting said cycles of said same first oscillating signal equals a preset end value.

Claim 16

The controller as claimed in claim 12 , wherein said predetermined pulse width is determined by multiplying said preset end value with a cycle period of said same oscillating signal.

Claim 17

The controller as claimed in claim 12 , wherein said signal generators control said pulse signals to have substantially the same pulse width by counting a same preset number of cycles of said same oscillating signal.

Claim 18

The controller as claimed in claim 12 , wherein said DC/DC converter comprises a plurality of switches and a plurality of inductors, and wherein said each pulse signal controls a pair of switches of said plurality of switches to control a current flowing through a corresponding inductor of said plurality of inductors.

Claim 19

The controller as claimed in claim 15 , wherein said current increases if said each pulse signal is in a first state, and wherein said current decreases if said each pulse signal is in a second state.

Claim 20

The controller as claimed in claim 15 , wherein said signal generators generate said pulse signals, by counting a same preset number of cycles of said same oscillating signal, to control a plurality of currents flowing through said inductors to have substantially the same ripple amplitude.

Claim 21

The controller as claimed in claim 12 , wherein if said output is less than a reference level, then said control circuitry increases said output by activating at least one signal generator of said signal generators one-by-one to generate at least one pulse signal, each of said at least one signal generator activated in response to a clock pulse of a clock signal; and wherein if said output increases to said reference level, then said control circuitry halts the activation of said signal generators.