Step-down power supply circuit
US8890503B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 16, 2012 |
| Grant date | Nov 18, 2014 |
| Priority date | — |
| Expiry date | Jun 4, 2033 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F1/575
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A power supply has first and second reference voltage sources; a step-down voltage generator, including a transistor supplied with a first voltage, a resistor string between the transistor and a second voltage, and an op-amp which controls the transistor, and outputting the voltage at a first node among nodes in the resistor string; switches, coupled to the nodes; a comparison circuit, which compares the voltage at a common node the switches coupling in common with the second reference voltage source; and a calibration control circuit, which selects any switch according to a comparison result to calibrate. During calibration, the calibration control circuit couples a second node among the nodes to a non-inverting terminal of the op-amp, and the first reference voltage source to an inverting terminal of the op-amp, and after calibration, couples the common node to the non-inverting terminal, and the second reference voltage source to the inverting terminal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.