Heat compensation circuit and method for executing in multi-phase DC/DC converter

Abstract

A temperature compensation circuit is used in a peak current control multi-phased DC / DC converter, the temperature for each phase in the converter being sensed (72) to generate corresponding first signals (Tcomp) for all the phases. The first signals are averaged to generate a second signal (Tavg) corresponding to the average temperature of all the phases and for each phase, a third signal (TCC) is generated corresponding to the difference between the first signal and the second signal. The third signal is then used to adjust the duty cycle of each phase to control the temperature of each phase to be substantially equal to the average temperature. In the steady state, the output voltage of the converter is a desired regulated voltage and the temperatures of the phases are balanced.

Description

technical field

[0001] The present invention relates to multiphase DC / DC converters, and in particular to the thermal control of each phase of said converter. Background technique

[0002] Multiphase DC / DC converters are often used in high current applications, such as for generating load currents of 100A or more. Converters employing multiple phases allow sharing of current generation, reduce ripple, and achieve other well-known benefits. There may be two or more phases. For optimal operation, each phase should be identical, but this is not possible due to practical considerations.

[0003] For a multi-phase current mode DC / DC converter, each phase typically includes: a pulse width modulation (PWM) comparator; an RS flip-flop, which is used to switch the transistor on and off at a certain duty cycle for regulation ; inductors; current sensing devices (such as low value resistors). The on-time of each phase is controlled by a phase-controlled clock. When a switch is on,...

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