Summation circuit in DC-DC converter
AssigneeSTMicroelectronics (Shenzhen) R&D Co. Ltd
InventorsJun Liu, Haibo Zhang
Life of this patent
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Abstract
An integrated circuit includes a saw-tooth generator including a saw tooth node configured to have a saw-tooth voltage generated thereon; and a first switch having a first end connected to the saw tooth node. The integrated circuit further includes a second switch coupled between an output node and an electrical ground, wherein the first switch and the second switch are configured to operate synchronously. A first current source is connected to the saw tooth node. A second current source is connected to the output node.
Claims20
A power supply comprising:
- a summation circuit comprising
- an output node,
- a current sense input node,
- a first switch coupled between the output node and a reference voltage node, the first switch comprising a control node configured to be coupled to a waveform generator,
- a first current source connected to the output node,
- a first capacitor coupled between the output node and the current sense input node,
- a first resistor coupled between the current sense input node and the reference voltage node, and
- a resistor coupled in series with a first capacitor, wherein the first capacitor and the resistor in combination are coupled in parallel with the first switch.
An integrated circuit comprising:
- a summation circuit comprising
- an output node,
- a current sense input node configured to be coupled to a current sensing circuit of a power supply,
- a first switch coupled between the output node and an supply voltage node, the first switch comprising a control node configured to be coupled to a waveform generator;
- a first current source connected to the output node,
- a first capacitor coupled between the output node and the current sense input node,
- a first resistor coupled between the current sense input node and the supply voltage node, and
- a resistor coupled in series with a first capacitor, wherein the first capacitor and the resistor in combination are coupled in parallel with the first switch;
- and
- a sawtooth generator comprising
- an amplifier having a first input coupled to a sawtooth node, a second input coupled to a reference voltage node,
- a second current source coupled to a sawtooth node, and
- a second switch coupled between the sawtooth node and the supply voltage node, the second switch a control node coupled to an output of the amplifier and to a control node of the first switch.
A method of operating a power supply, the method comprising:
- generating a first waveform voltage, generating the first waveform voltage comprising charging a first capacitor with a first current source and activating a first switch coupled to the first capacitor when the first waveform voltage crosses a first threshold;
- and
- generating a second waveform voltage, generating the second waveform voltage comprising charging a first circuit with a second current source and activating a second switch when the waveform voltage crosses the first threshold, wherein the first circuit comprises a second capacitor coupled in series with a resistor.
Dependencies are inferred from the claim text.