Circuit for discharging an electrical load, power output stage comprising such a discharge circuit for the control of plasma display cells, and related system and method
AssigneeSTMicroelectronics S.r.l.
InventorsFrançois Ravatin, Gilles Troussel
Life of this patent
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Abstract
An embodiment of a discharge circuit comprises an output circuit with one output connected to an electrical load to absorb a discharge current given by the load when a logic signal commands a discharge of the load. The discharge circuit also comprises a control circuit to give the output circuit an appropriate control signal so that a slope of an output potential of the output circuit diminishes gradually when the logic signal commands a discharge of the load. Limiting the slope of the output potential gradually (and not suddenly) may limit the electromagnetic radiation generated by these variations.
Claims20
A circuit, comprising:
- an output node;
- an output stage operable, in response to a control signal, to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to generate the control signal having,
- a first magnitude during a first portion of the duration, and
- a second magnitude during a second portion of the duration.
A circuit, comprising:
- an output node;
- an output stage operable, in response to a control signal, to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to generate the control signal having,
- a first magnitude during a first portion of the duration,
- a second magnitude during a second portion of the duration;
- and
- a reference node;
- and
- wherein the output stage includes a transistor having a control node coupled to the control stage, a first drive node coupled to the output node, and a second drive node coupled to the reference node.
A circuit, comprising:
- an output node;
- an output stage operable to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to cause the slope to have,
- a first magnitude during a first portion of the duration, and
- a second magnitude during a second portion of the duration;
- wherein the control stage is further operable to generate a control signal and to couple the control signal to the output stage, the control signal having a first amplitude during the first portion of the duration and having a second amplitude during a second portion of the duration.
A circuit, comprising:
- an output node;
- an output stage operable to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to cause the slope to have,
- a first magnitude during a first portion of the duration, and
- a second magnitude during a second portion of the duration;
- wherein the control stage comprises:
- a first generator operable to generate a control signal having a first amplitude and to couple the control signal to the output stage during the first portion of the duration, and
- a second generator coupled to the first generator and operable to cause the control signal to have a second amplitude during the second portion of the duration.
A system, comprising:
- a display screen having a cell;
- and
- a driver coupled to screen, the driver comprising,
- an output stage operable, in response to a control signal, to generate a cell driving signal having an edge with a duration and a slope, and
- a control stage coupled to the output stage and operable to generate the control signal having,
- a first magnitude during a first portion of the duration, and
- a second magnitude during a second portion of the duration.
A circuit, comprising:
- an output node;
- an output stage operable, in response to a control signal, to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to generate the control signal having,
- a first magnitude during a first portion of the duration, and
- a second magnitude during a second portion of the duration;
- wherein the first magnitude is substantially constant during the first portion of the duration, and the second magnitude is substantially constant during the second portion of the duration.
A system, comprising:
- a display screen having a cell;
- and
- a driver coupled to screen, the driver comprising,
- an output node;
- an output stage operable to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to
- generate a control signal, the control signal having a first amplitude during the first portion of the duration and having a second amplitude during a second portion of the duration,
- couple the control signal to the output stage, and
- cause the slope to have a first magnitude during a first portion of the duration, and a second magnitude during a second portion of the duration.
A system, comprising:
- a display screen having a cell;
- and
- a driver coupled to screen, the driver comprising,
- an output node;
- an output stage operable to generate at the output node an output signal having an edge with a duration and a slope;
- and
- a control stage coupled to the output stage and operable to cause the slope to have a first magnitude during a first portion of the duration, and a second magnitude during a second portion of the duration, the control stage comprising
- a first generator operable to generate a control signal having a first amplitude and to couple the control signal to the output stage during the first portion of the duration, and
- a second generator coupled to the first generator and operable to cause the control signal to have a second amplitude during the second portion of the duration.
Dependencies are inferred from the claim text.