Chopper-stabilized operational amplifier including integrated circuit with true random voltage output
US6147552A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 27, 1998 |
| Grant date | Nov 14, 2000 |
| Priority date | — |
| Expiry date | Oct 27, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03B29/00
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
An improved chopper stabilized operational amplifier is disclosed, along with an improved method of timing the switchings of chopper switches in such an amplifier. The disclosure includes an integrated circuit and method for generating a true random voltage signal having a truly random RMS voltage value within a selected range. The true random voltage signal is obtained by amplifying and bandpass filtering random white noise voltages generated by a component of the circuit. The white noise voltages include shot noise voltages generated by bipolar transistors in an input amplifier stage. The random signal generator circuit and method is employed with an oscillator to form a random clock signal generator on the integrated circuit chip. The amount of time between each clocking pulse output by the random clock signal generator truly randomly varies within a selected range of time, and repeats only by random chance. The random clock signal generator is used to control the amount of time between each switching of a chopper switch in a chopper-stabilized operational amplifier, so that the chopping frequency is truly random. The truly random variation of the chopper switching frequency red…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.