Current mode switching regulator with programmed offtime

Claim 2

A power supply regulator comprising: a common terminal; an input terminal for applying a direct current input; an output terminal; a catch diode having a first terminal connected to the common terminal; an inductor having a first terminal connected to a second terminal of the catch diode and a second terminal connected to the output terminal; a capacitor having a first terminal connected to the common terminal, and a second terminal connected to the output terminal; switch means connected between the second terminal of the catch diode and the input terminal for switching the direct current input between an on time and an off time; and means operatively connected to the switch means for varying the off time of the switch means, wherein the duration of the off time is proportional to the difference between the voltage at the input terminal and the voltage at the output terminal divided by the voltage at the input terminal.

Claim 3

The regulator of claim 1, wherein the means for varying comprises: means for determining the starting point of a timing ramp for the off time of the switch means; and means for dtermining the slope of the off time timing ramp of the switch means; wherein the duration of the off time of the switch means is a function of the starting point and slope of the off time timing ramp.

Claim 4

The regulator of claim 2, wherein the means for determining the slope comprises capacitor means for charging to a voltage.

Claim 5

The regulator of claim 2, wherein the means for determining the starting point comprises secondary inductor means for carrying an induced voltage.

Claim 6

The regulator of claim 4, wherein the secondary inductor means is a secondary winding on the inductor for smoothing the output voltage.

Claim 7

The regulator of claim 5, wherein the means for determining the starting point further comprises bias means for biasing an output of the inductor.

Claim 8

The regulator of claim 3, further comprising current control means connected between the means for varying and the switch means, for driving the switch means between the on time and the off time in response to the means for varying.

Claim 9

The regulator of claim 7, wherein the means for varying turns the switch means off when the current control means detects a predetermined current through the switch means.

Claim 10

The regulator of claim 8, wherein the means for determining the starting point sets the starting point of the timing ramp of the off time at a voltage differing from a threshold voltage by a value proportional to the voltage at the input terminal minus the voltage at the output terminal.

Claim 11

The regulator of claim 4, wherein the means for determining the slope comprises capacitor means for charging to a voltage; and wherein the secondary inductor means sets the voltage to which the capacitor means charges while the switch means is in the on time state.

Claim 12

A power supply regulator comprising: a common terminal; an input terminal for applying a direct current input; an output terminal; a catch diode having a first terminal connected to the common terminal; an inductor having a first terminal connected to a second terminal of the catch diode and a second terminal connected to the output terminal; a capacitor having a first terminal connected to the common terminal, and a second terminal connected to the output terminal; switch means connected between the second terminal of the catch diode and the input terminal for switching the direct current input between an on time and an off time; and means operatively connected to the switch means for varying the off time of the switch means as a function of voltages at the input and output terminals; wherein the means for varying comprises: means for determining the starting point of a timing ramp for the off time of the switch means; means for determining the slope of the off time timing ramp of the switch means; wherein the duration of the off time of the switch means is a function of the starting point and slope of the off time timing ramp; and wherein the means for determining the starting point comprises secondary inductor means for carrying an induced voltage.

Claim 13

A power supply regulator comprising: a common terminal; an input terminal for applying a direct current input; an output terminal; a catch diode having a first terminal connected to the common terminal; an inductor having a first terminal connected to a second terminal of the catch diode and a second terminal connected to the output terminal; a capacitor having a first terminal connected to the common terminal, and a second terminal connected to the output terminal; switch means connected between the second terminal of the catch diode and the input terminal for switching the direct current input between an on time and an off time; and means operatively connected to the switch means for varying the off time of the switch means as a function of voltages at the input and output terminals; wherein the means for varying comprises: means for determining the starting point of a timing ramp for the off time of the switch means; means for determining the slope of the off time timing ramp of the switch means; wherein the duration of the off time of the switch means is a function of the starting point and slope of the off time timing ramp; and wherein the means for determining the starting point comprises secondary inductor means for carrying an induced voltage.

Claim 14

A power supply regulator comprising: a common terminal; an input terminal for applying a direct current input; an output terminal; a catch diode having a first terminal connected to the common terminal; an inductor having a first terminal connected to a second terminal of the catch diode and a second terminal connected to the output terminal; a capacitor having a first terminal connected to the common terminal, and a second terminal connected to the output terminal; switch means connected between the second terminal of the catch diode and the input terminal for switching the direct current input between an on time and an off time; and means operatively connected to the switch means for varying the off time of the switch means as a function of voltages of the input and output terminals; wherein the means for varying comprises: means for determining the starting point of a timing ramp for the off time of the switch means; and means for determining the slope of the off time timing ramp of the switch means; wherein the duration of the off time of the switch means is a function of the starting point and slope of the off time timing ramp, and wherein the means for determining the slope comprises capacitor means for charging to a voltage; and further comprising current control means connected between the means for varying and the switch means, for driving the switch means between the on time and the off time in response to the means for varying.

Claim 15

A power supply regulator comprising: a common terminal; an input terminal for applying a direct current input; an output terminal; a catch diode having a first terminal connected to the common terminal; an inductor having a first terminal connected to a second terminal of the catch diode and a second terminal connected to the output terminal; a capacitor having a first terminal connected to the common terminal, and a second terminal connected to the output terminal; switch means connected between the second terminal of the catch diode and the input terminal for switching the direct current input between an on time and an off time; and means operatively connected to the switch means for varying the off time of the switch means as a function of voltages of the input and output terminals; wherein the means for varying comprises: means for determining the starting point of a timing ramp for the off time of the switch means; and means for determining the slope of the off time timing ramp of the switch means; wherein the duration of the off time of the switch means is a function of the starting point and slope of the off time timing ramp, and wherein the means for determining the slope comprises capacitor means for charging to a voltage; and further comprising current control means connected between the means for varying and the switch means, for driving the switch means between the on time and the off time in response to the means for varying.