DC converter and method for selecting a frequency of same
AssigneeAms AG
InventorsStefan Wiegele, Thomas Jessenig, Peter Trattler
Life of this patent
Estimating the term…
Abstract
In one embodiment, a DC converter has a frequency adjusting device with a frequency selection circuit, a frequency change-over switch (17), a frequency generator (18), a threshold signal generator (19), a state machine (20) and a unit (21) for providing a ready signal (S3). The frequency selection circuit has an output (15), at which a control signal (S5) is provided, which is set up to select a frequency of the switching frequency signal (DCLK) of the DC converter. The invention further relates to a method for selecting a frequency of the DC converter.
Claims11
A DC converter comprising:
- a frequency adjusting device comprising:
- a frequency selection circuit, comprising
- a first input that is supplied with a first threshold signal in dependence on a switching frequency signal of the DC converter,
- a second input that is supplied with a second threshold signal in dependence on the first threshold signal,
- a third input that is supplied with a ready signal of the DC converter, and
- an output, at which a control signal is provided that is designed for selecting a frequency of the switching frequency signal of the DC converter;
- a frequency change-over switch that is coupled to the output of the frequency selection circuit and that is supplied with a main clock signal of the DC converter, a first clock signal with a first clock frequency and at least one second clock signal with a second clock frequency, wherein said frequency change-over switch is designed for providing the switching frequency signal of the DC converter in dependence on the control signal, the first and/or the at least one second clock signal;
- a frequency generator that is supplied with the main clock signal and is designed for providing the first and at least the at least one second clock signal;
- a threshold signal generator that is supplied with the switching frequency signal of the DC converter and is adapted for respectively providing the first and the second threshold signal in dependence on the switching frequency signal;
- a state machine that is supplied with the ready signal and the switching frequency signal and is designed for providing a driving signal for the DC converter;
- and
- a unit for providing the ready signal in dependence on a first and a second voltage provided by the DC converter,
- wherein the control signal is provided in dependence on the first threshold signal, the second threshold signal and the ready signal,
- wherein the driving signal is provided in dependence on the switching frequency signal and the ready signal, and
- wherein the DC converter is designed for supplying a display device with organic light-emitting diodes or an active matrix display device with organic light-emitting diodes.
A method for selecting a frequency of a DC converter, comprising:
- supplying a first threshold signal in dependence on a switching frequency signal of the DC converter;
- supplying a second threshold signal in dependence on the first threshold signal;
- supplying a ready signal of the DC converter;
- providing a control signal in dependence on the first threshold signal, the second threshold signal and the ready signal;
- and
- selecting a frequency of the switching frequency signal in dependence on the control signal.
Dependencies are inferred from the claim text.