Average output current estimation using primary-side sensing

摘要

In one embodiment, an apparatus includes a transformer comprising a primary side and a secondary side. A switch is coupled to the primary side. A control signal circuit is configured to: sample a first current on the primary side of the transformer; estimate a second current value on the secondary side of the transformer using the sampling of the first current on the primary side and a turn ratio of the transformer; and output a signal to control a turn on time for the switch.