Method and apparatus for precise modulation of a reference current
US5367248A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 13, 1992 |
| Grant date | Nov 22, 1994 |
| Priority date | — |
| Expiry date | Oct 13, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/20
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
The invention provides a method and apparatus for precise modulation of a reference current. A current generating apparatus in accordance with the invention is provided on an integrated circuit chip and includes a series connected chain comprising in the recited order: (a) an externally-set reference current source; (b) a current-to-voltage (I/V) converter for converting the reference current into an on-chip reference voltage, V.sub.ref ; (c) a voltage-to-current (V/I) converter for converting the reference voltage V.sub.ref into an on-chip, internal reference current I.sub.iref ; (d) a single-ended, voltage-operated current switch for modulating the internal reference current I.sub.iref to produce therefrom a modulated current signal, I.sub.M ; (e) a current-driven filter which receives the modulated current signal I.sub.M and produces therefrom a filtered voltage signal, V.sub.F ; (f) a voltage-to-current (V/I) converter for converting the filtered output voltage signal V.sub.F of the filter back into a current, I.sub.F, and (g) a current multiplier for multiplying the magnitude of the current output by the V/I converter to thereby produce an output current, I.sub.OUT.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.