Power Saving Feature In Multiphase dc/dc Converter using Identity Switching
Publication Date: 2014-Jun-12
The IP.com Prior Art Database
Disclosed is a method to save power during multiphase dc/dc conversion. The solution is to add a time delay of a finite length into the turn-off of the adjacent low-side Field Effect Transistor (FET) when the high-side FET fires, in order to reduce the current flowing through body diode.
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Power Saving Feature In Multiphase dc /dc Converter using Identity Switching
Existing methods use a like-dot coupled inductor in direct current/direct current (dc/dc) conversion with an identity switching matrix. A system in which only one silicon device operates at any given time can cause power loss across the body diode of the low-side Field Effect Transistors (FETs) of that system. [*]
A method is needed to save power during multiphase dc/dc conversion.
The solution is to add a time delay of a finite length into the turn-off of the adjacent low-side FET when the high-side FET fires, in order to reduce the current flowing through body diode. (Figure 1)
Figure 1: A two-phase dc/dc converter using the like dot coupled inductor. This circuit consists of four switching devices.
Figure 2 illustrates the current flow of the system for operating in the identity matrix. To keep the current ripple seen by the core to a minimum, high-side (101 & 103) and low-side devices (102 & 104) cannot simultaneously turn on. The turning on of a high-side FET forces the current flowing through an adjacent low-side FET to change to negative. Operating only one device at a time eliminates the current from changing to negative. At time equals T2, the low-side FET is turned off as the next high-side FET is turned on. At the time between T2 and T3, the output load current flows through the body diodes of (102 and 104).
Figure 2: The current flow of the system for operating in the identi...