3 ms·
The description of the regulation of the 3V3 circuit is IMHO misleading. The inductor isn't a magnetic amplifier (multiple coils would be needed), but rather a
by guenthert 5y ago
The description of the regulation of the 3V3 circuit is IMHO misleading. The inductor isn't a magnetic amplifier (multiple coils would be needed), but rather a filter element.
- kens 5y agoAre you familiar with the use of magnetic amplifiers to regulate 3.3 V outputs? I traced the circuit and it's a magnetic amplifier. The same winding is used for control and output, as is typical in power supplies.
- guenthert 5y agoNo, I am not and had difficulties finding hints. Eventually I found https://www.ti.com/lit/ml/slup129/slup129.pdf https://www.ti.com/lit/ml/slup129/slup129.pdf which I found helpful. "Magnetic Amplifiers Although called a magnetic amplifier; this application really uses an inductive element as a controlled switch. A mag amp is a coil of wire wound on a core with a relatively square B-H characteristic. This gives the coil too operating modes: when unsaturated, the core causes the coil to act as a high inductance capable of supporting a large voltage with little or no current flow. When the core saturates, the impedance of the coil drops to near zero, allowing current to flow with negligible voltage drop. Thus a mag amp comes the closest yet to a true "ideal switch" with significant benefits to switching regulators."