Signal sampling method, sampling circuit, integrated circuit and switching power supply thereof
AssigneeSilergy Semiconductor Technology (Hangzhou) LTD
InventorsZhan Chen, Jin Jin, Guiying Zhang, Hongxing Wang
Life of this patent
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Abstract
A sampling circuit for a switching power supply, can include: a first sampling circuit configured to acquire a first sampling signal of a current flowing through an inductor in the switching power supply; and a second sampling circuit configured to obtain a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply, and to superimpose the compensation signal on the first sampling signal to generate a second sampling signal.
Claims18
A sampling circuit for a switching power supply, the sampling circuit comprising:
- a) a first sampling circuit configured to acquire a first sampling signal of a current flowing through an inductor in the switching power supply;
- b) a second sampling circuit configured to obtain a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply, and to superimpose the compensation signal on the first sampling signal to generate a second sampling signal;
- and
- c) wherein the compensation signal begins to increase linearly when a control signal that controls the power switch to turn off is detected, and stops increasing linearly when a zero crossing from positive to negative is detected for the current flowing through the inductor.
A sampling circuit for a switching power supply, the sampling circuit comprising:
- a) a first sampling circuit configured to acquire a first sampling signal of a current flowing through an inductor in the switching power supply;
- b) a second sampling circuit configured to obtain a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply, and to superimpose the compensation signal on the first sampling signal to generate a second sampling signal;
- and
- c) wherein the second sampling circuit comprises a current source configured to generate a charging current and a first capacitor, wherein the charging current charges the first capacitor within the turn-off delay time to generate the compensation signal on the first capacitor.
A method of signal sampling method, the method comprising:
- a) obtaining a first sampling signal of a current flowing through an inductor in a switching power supply;
- b) obtaining a compensation signal with a same rising slope as the first sampling signal within a turn-off delay time of a power switch in the switching power supply;
- c) superimposing the compensation signal on the first sampling signal to generate a second sampling signal;
- and
- d) wherein the compensation signal begins to increase linearly when a control signal that controls the power switch to turn off is detected, and stops increasing linearly when a zero crossing from positive to negative is detected for the current flowing through the inductor.
Dependencies are inferred from the claim text.