Control Method for DC/DC Converters and Switching Regulators

1 . A method for controlling a switching regulator, where the switching regulator includes an inductor operating under the control of one or more switches, the method comprising the steps of:

configuring the one or more switches into a first state to couple the inductor between an input supply and ground so that an increasing current passes from the input supply through the inductor;

configuring the one or more switches into a second state when the magnitude of the increasing current has reached a predetermined level where the second state couples the inductor between the input supply and a load so that a decreasing current passes from the input supply through the inductor; and

configuring the one or more switches into the first state to limit the duration of the second state to a predetermined period of time.

2 . A method as recited in claim 1 that further comprises the steps of:

generating a voltage that is proportional to the increasing current;

comparing the generated voltage to the a reference voltage; and

triggering a one-shot (constant discharge-time) timer when the generated voltage exceeds the reference voltage.

3 . A method as recited in claim 1 where the one or more switches includes a first switch connected between the inductor and ground and a second switch connected between the inductor and the load.

4 . A method as recited in claim 3 where the switching regulator is a boost, or voltage increasing regulator.

5 . A circuit for controlling a switching regulator, where the switching regulator includes an inductor and one or more switches, the circuit comprising:

a switching control circuit configured to operate the one or more switches in a repeating sequence that includes a first state in which the inductor is coupled between an input supply and ground so that an increasing current passes from the input supply through the inductor and a second state in which the inductor is coupled between the input supply and a load so that a decreasing current passes from the input supply through the inductor;

a circuit configured to cause the switching circuit to select the second state when the magnitude of the increasing current has reached a predetermined level; and

a timing circuit configured to cause the switching circuit to select the first state a predetermined period of time after the initiation of each second state.

6 . A circuit as recited in claim 5 that further comprises the steps of:

a one-shot timer;

means for generating a current monitoring voltage that is proportional to the increasing current;

a comparator that triggers the one-shot timer when the current monitoring voltage exceeds the reference voltage.

7 . A circuit as recited in claim 5 where the one or more switches includes a first switch connected between the inductor and ground and a second switch connected between the inductor and the load.

8 . A circuit as recited in claim 7 where the switching regulator is a boost, or voltage increasing regulator.

9 . A method for controlling a switching regulator, where the switching regulator includes an inductor operating under the control of one or more switches, the method comprising the steps of:

configuring the one or more switches into a first state to couple the inductor between an input supply and a load so that an increasing current passes from the input supply through the inductor;

configuring the one or more switches into a second state when the magnitude of the increasing current has reached a predetermined level where the second state couples the inductor between the ground and the load so that a decreasing current passes through the inductor to the load; and

configuring the one or more switches into the first state to limit the duration of the second state to a predetermined period of time.

10 . A method as recited in claim 9 that further comprises the steps of:

generating a voltage that is proportional to the increasing current;

comparing the generated voltage to the a reference voltage; and

triggering a one-shot timer when the generated voltage exceeds the reference voltage.

11 . A method as recited in claim 10 where the one or more switches includes a first switch connected between the inductor and ground and a second switch connected between the inductor and the input supply.

12 . A method as recited in claim 12 where the switching regulator is a buck, or voltage decreasing regulator.

13 . A circuit for controlling a switching regulator, where the switching regulator includes an inductor and one or more switches, the circuit comprising:

a switching control circuit configured to operate the one or more switches in a repeating sequence that includes a first state in which the inductor is coupled between an input supply and a load so that an increasing current passes from the input supply through the inductor and a second state in which the inductor is coupled between ground and the load so that a decreasing current passes through the inductor to the load;

a circuit configured to cause the switching circuit to select the second state when the magnitude of the increasing current has reached a predetermined level; and

a timing circuit configured to cause the switching circuit to select the first state a predetermined period of time after the initiation of each second state.

14 . A circuit as recited in claim 13 that further comprises the steps of:

a one-shot timer;

means for generating a current monitoring voltage that is proportional to the increasing current;

a comparator that triggers the one-shot timer when the current monitoring voltage exceeds the reference voltage.

15 . A circuit as recited in claim 13 where the one or more switches includes a first switch connected between the inductor and ground and a second switch connected between the inductor and the input supply.

16 . A circuit as recited in claim 13 where the switching regulator is a buck, or voltage decreasing regulator.