Drive circuit
A fully isolated drive circuit to be used for regulating an output voltage across a load. The isolated drive circuit may charge, discharge, or preserve the load charge using a controller that controls one or more switches. The controller may operate a switch according to an internal/external clock or an external control signal received by the controller. The isolated drive circuit may be an effective solution to simplify the drive design and decrease the amount of energy dissipated by the drive, especially when the load, associated with the drive, requires a high input voltage level.
1 . An apparatus comprising:
a synchronization circuit configured to generate a pre-charge signal based on a first enable signal;
an inductive element; and
a switching circuit coupled to the inductive element and configured to switch, based on the first enable signal or the pre-charge signal, between different states of the apparatus, wherein the different states comprise a first state in which a voltage is applied across the inductive element and a second state in which power is transferred between the inductive element and a load, and wherein the switching circuit is configured to charge the load comprising a gate terminal of a transistor of a DC-DC converter; and
a controller configured to control the switching circuit based on a closed loop control of a measured parameter in the DC-DC converter.
2 . The apparatus of claim 1 , wherein the pre-charge signal is configured to precede a second enable signal.
3 . The apparatus of claim 1 , wherein the synchronization circuit is configured to generate, based on a rise or fall of the first enable signal, the pre-charge signal.
4 . The apparatus of claim 1 , wherein the switching circuit is configured to transfer power between the inductive element and a second load in a staggered manner with respect to transfer of power to the load.
5 . The apparatus of claim 1 ,
wherein the inductive element comprises a plurality of magnetically coupled windings around a common core; and
wherein each of the plurality of magnetically coupled windings transfers power with a corresponding load.
6 . The apparatus of claim 1 , wherein the synchronization circuit includes a phase-locked loop (PLL) or a delay-locked loop (DLL).
7 . The apparatus of claim 1 , wherein the switching circuit includes an H bridge.
8 . The apparatus of claim 1 , wherein the switching circuit is configured to periodically change the voltage across the inductive element between multiple direct current (DC) voltage levels.
9 . The apparatus of claim 1 , wherein the controller switches one or more switches of the switching circuit using zero-voltage switching or zero-current switching.
10 . The apparatus of claim 1 , wherein the measured parameter is one of a rise time sampling of voltage across the load or a peak current flowing through the inductive element.
11 . The apparatus of claim 1 , wherein the inductive element comprises a first inductor having a primary winding and a second inductor having a secondary winding, wherein a voltage applied by the switching circuit across the first inductor induces a voltage across the second inductor.
12 . A system comprising:
a synchronization circuit configured to:
determine, based on a first enable signal, a predicted characteristic of a second enable signal to be received after the first enable signal; and
generate, prior to receipt of the second enable signal and based on the predicted characteristic, a pre-charge signal;
a controller configured to receive the pre-charge signal and the first enable signal and generate one or more control signals; and
a switching circuit comprising switches and configured to switch, based on the one or more control signals, between a first state in which a voltage is applied across an inductive element and a second state in which power is transferred between the inductive element and a load.
13 . The system of claim 12 , wherein the synchronization circuit is configured to determine the predicted characteristic by detecting a frequency or a phase of the first enable signal.
14 . The system of claim 12 , wherein the controller is configured to:
based on the pre-charge signal, enable a current to flow through the inductive element; and
increase the current by maintaining the voltage across the inductive element.
15 . The system of claim 12 , wherein the controller is configured to use zero-voltage switching or zero-current switching to control one or more switches of the switching circuit.
16 . A method comprising:
receiving a first enable signal for regulating voltage;
determining, based on the first enable signal, at least one predicted characteristic of a second enable signal to be received after the first enable signal;
generating, based on the at least one predicted characteristic, a pre-charge signal; and
switching, based on the first enable signal or the pre-charge signal, a switching circuit between a first state in which a voltage is applied across an inductive element and a second state in which power is transferred between the inductive element and a load.
17 . The method of claim 16 , wherein the determining the at least one predicted characteristic comprises detecting a frequency or a phase of the first enable signal.
18 . The method of claim 16 , further comprising:
based on the pre-charge signal, enabling a current to flow through the inductive element; and
increasing the current by maintaining the voltage across the inductive element.
19 . The method of claim 16 , further comprising:
controlling one or more switches of the switching circuit using zero-voltage switching or zero-current switching.