Multiphase switching power supply with robust current sensing and shared amplifier
US9793800B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 4, 2017 |
| Grant date | Oct 17, 2017 |
| Priority date | — |
| Expiry date | Apr 4, 2037 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M1/0009
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
In a multiphase, current mode controlled switching power supply, current through the inductors in the various phases is sensed to determine when to turn off the switching transistors. An AC current feedback path, sensing the ramping ripple current, is separate from the DC current path, sensing the lower frequency average current. A shared differential amplifier has its inputs multiplexed to receive only the DC component signals from all the phases. The gain of the amplifier is set so that the DC sense signal has the proper proportion to the AC sense signal. The output of the amplifier is sampled and held for each phase using a second multiplexer. The AC sense signal and the amplified DC sense signal, for each phase, are combined by a summing circuit. The composite sense signal is applied to a comparator for each phase to control the duty cycle of the associated switch.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.