US 6,215,290 B1 · Multi-phase and multi-module power supplies with balanced current between phases and modules

Abstract

A multi-phase power supply utilizes a current sensor including a sensor inductor winding connected in parallel with a filter inductor winding at the output of each phase for sensing the phase currents and balancing the current by adjusting the duty cycle of each phase through feedback control. In addition, in a multi-module power supply configuration, current between power supply modules is balanced through use of the same current sensor and current sharing technique. Each phase of the power supply includes at least one input power source and a current sensor. The sensor inductor winding and the filter inductor winding have the same number of turns and are wound about a magnetic core also present at each phase. A differential amplifier at each phase senses and amplifies any voltage difference between the outputs of the sensor inductor winding and the corresponding filter inductor winding. A current-sharing bus is formed between each of the phases, carrying the summed and averaged outputs from all the differential amplifiers. A feedback correction circuit at each phase utilizes the voltage on the current-sharing bus as a reference to control a pulse width modulator in adjusting the duty cycle of the corresponding phase, thereby balancing the load current among the phases. In a multi-module, multi-phase power supply, the current-sharing bus and a voltage-sharing bus are extended between each module and the phases of each module to achieve the same current balancing between all phases and modules.

Claims32

Dependent claims

A multi-phase power supply which balances current between phases, comprising:

at least one input power source for supplying current for each of said phases;
a filter capacitor at the output of each of said phases;
a sensor inductor winding at the output of each of said phases, said sensor inductor winding having an input and an output;
a filter inductor winding at the output of each of said phases, said filter inductor winding having an input and an output, wherein said sensor inductor winding and said filter inductor winding have the same number of turns and said input of said sensor inductor winding and said input of said filter inductor winding are connected together at the output of each of said phases;
a magnetic core at each of said phases, about which a corresponding sensor inductor winding and a corresponding filter inductor winding are wound;
a differential amplifier at each of said phases for sensing and amplifying a voltage difference between the outputs of said corresponding sensor inductor winding and said corresponding filter inductor winding;
circuitry to sum and average outputs from all differential amplifiers, forming a current-sharing bus between each of said phases,
a feedback correction circuit at each of said phases which utilizes the voltage on said current-sharing bus as a reference;
and
a pulse width modulator at each of said phases controlled by a corresponding feedback correction circuit for adjusting the duty cycle of a corresponding phase.

7 more elements

Dependencies are inferred from the claim text.

Multi-phase and multi-module power supplies with balanced current between phases and modules

Life of this patent

Multi-phase and multi-module power supplies with balanced current between phases and modules

Life of this patent

Abstract

Claims32