Switching power converter with secondary to primary messaging
AssigneeDialog Semiconductor GmbH
InventorsJianming Yao, Pengju Kong, Yong Li, Junjie Zheng
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Abstract
A primary-only power supply enables transmission of a signal or message from the secondary side of an isolated power supply to the primary side. To enable robust detection of the message without interfering with primary side sensing for output regulation, a configurable impedance current path is configured between the primary winding and ground. The primary side controller controls the configurable impedance current path to have a relatively low impedance during the normal mode and a relatively high impedance during the messaging mode.
Claims20
A switching power converter, comprising:
- a transformer isolating a primary side of the switching power converter from a secondary side of the switching power converter, the transformer including a primary winding coupled to an input and a secondary winding coupled to an output of the switching power converter;
- a first primary side switch coupled to the primary winding of the transformer, the first primary side switch to control current flow through the primary winding based on switching of the first primary side switch;
- a primary side controller to control switching of the first primary side switch to regulate the output of the switching power converter based on primary-side sensing, and to select between a normal mode and a messaging mode, the primary side controller to detect digital messages generated on the secondary side during the messaging mode based on primary side sensing of current through the primary winding.
A method for controlling a switching power converter, the switching power converter including a transformer with a primary winding coupled to an input and a secondary winding coupled to an output of the switching power converter, and a first primary side switch coupled to the primary winding of the transformer, the transformer electrically isolating a primary side of the switching power converter corresponding to the primary winding and a secondary side of the switching power converter corresponding to the secondary winding, the first primary side switch controlled by a primary side switch controller, the method comprising:
- sensing by the primary side switch controller, primary side feedback signals generated on the primary side of the switching power converter;
- controlling, by the primary side switch controller, switching of the first primary side switch based on the primary side feedback signals;
- selecting between operating the primary side switch controller in a normal mode and a messaging mode;
- and
- detecting a digital message reflected on the primary winding from the secondary winding during the messaging mode, the digital message detected via primary side sensing of a current through the primary winding.
A switching power converter, comprising:
- a transformer including a primary winding coupled to an input and a secondary winding coupled to an output of the switching power converter;
- a first primary side switch coupled to the primary winding of the transformer, the first primary side switch to control current flow through the primary winding based on switching the first primary side switch;
- a second primary side switch switching between a first state during a normal mode and a second state during a messaging mode, wherein the second primary side switch causes a current path through the primary side winding and the first primary side switch to have a first impedance when the second primary side switch is in the first state during the normal mode, and wherein the second primary side switch causes the current path through the primary side winding and the first primary side switch to have a second impedance when the second primary side switch is in the second state during the messaging mode, the second impedance higher than the first impedance;
- a primary side controller on the primary side of the switching power converter, the primary side controller to control switching of the first primary side switch, to control switching of the second primary side switch to select between the normal mode and the messaging mode, and to detect a digital message reflected on the primary winding from the secondary winding during the messaging mode.
Dependencies are inferred from the claim text.