Constant ON-time controller for a buck converter
US7019504B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 8, 2003 |
| Grant date | Mar 28, 2006 |
| Priority date | — |
| Expiry date | Jun 22, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02M3/156
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A constant ON-time controller for a buck converter utilizes dual symmetrical ramps. The ramps may be generated artificially or by sensing the voltage across a sense resistor in the output. The ramp may also be generated by sensing the voltage across the “ON” resistance of the low side FET in the switching regulator. A modified output voltage has one of the ramps superimposed and a modified reference voltage has the other ramps superimposed. The modified output voltage and the modified reference voltage are compared to determine when to start the ON-time of the buck converter. The dual ramps reduce, noise susceptibility. The ON-time is stopped in response to charging a capacitor with the regulator input voltage. An offset may also be generated representing the difference between the average output voltage and the reference voltage. The offset is used to generate a modified reference to compensate for the offset.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.