Bleeding switching regulator power rail through switching regulator ground side switch
AssigneeInternational Business Machines Corporation
InventorsWilliam Fast, Jr., Abraham Garcia, Adrian Glover
Life of this patent
Estimating the term…
Abstract
A switching regulator sources a power rail and includes a top side or input rail side switch, a bottom side or ground side switch, and an inductor. When the switching regulator is disabled or generally turned off, a bottom side transistor in the bottom side switch is pulsed on and off, or held on, to drain or bleed the power rail to ground. When the bottom side transistor is off and if there is a voltage across the inductor from the power rail at a switching node, current flows through a body diode of the top side switch to the input rail of the switching regulator.
Claims15
A method of bleeding charge from a power rail of a switching regulator through a ground side switch of the switching regulator, the switching regulator comprising:
- a controller;
- a switching node consisting of a connection to an input-rail-side switch, a connection to a ground-side switch, and an a connection to an inductor;
- and a power rail consisting of a connection to the inductor, a connection to a capacitor, a connection to a feedback rail, and a connection to a load;
- the method comprising:
- with the controller, opening the input-rail-side switch and opening the ground-side switch;
- determining, with the controller, whether an output voltage at the power rail is equal to ground;
- and
- if the output voltage at the power rail is not equal to ground, with the controller, cyclically closing the ground-side switch by cyclically pulsing on and off a ground-side transistor of the ground-side switch allowing current to flow from the power rail through the ground-side transistor of the ground-side switch until the output voltage at the power rail is equal to ground.
A switching regulator comprising:
- a controller;
- a switching node consisting of a connection to an input-rail-side switch, a connection to a ground-side switch, and an a connection to an inductor;
- a power rail consisting of a connection to the inductor, a connection to a capacitor, a connection to a feedback rail, and a connection to a load;
- wherein the controller is configured to:
- open the input-rail-side switch and open the ground-side switch of the switching regulator upon receipt of a signal to turn off the switching regulator;
- determine whether an output voltage at the power rail is equal to ground;
- and
- if the output voltage at the power rail is not equal to ground, cyclically close the ground-side switch by cyclically pulsing on and off a ground-side transistor of the ground-side switch allowing current to flow from the power rail through the ground-side transistor of the ground-side switch until the output voltage at the power rail is equal to ground.
An integrated circuit comprising a switching regulator, the switching regulator comprising:
- a controller;
- a switching node consisting of a connection to an input-rail-side switch, a connection to a ground-side switch, and an a connection to an inductor;
- a power rail consisting of a connection to the inductor, a connection to a capacitor, a connection to a feedback rail, and a connection to a load;
- wherein the controller is configured to:
- open the input-rail-side switch and open the ground-side switch of the switching regulator upon receipt of a signal to turn off the switching regulator;
- determine whether an output voltage at the power rail is equal to ground;
- and
- if the output voltage at the power rail is not equal to ground, cyclically close the ground-side switch by cyclically pulsing on and off a ground-side transistor of the ground-side switch allowing current to flow from the power rail through the ground-side transistor of the ground-side switch until the output voltage at the power rail is equal to ground.
Dependencies are inferred from the claim text.