Range changing using N and P channel FETS
US5144154A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 21, 1990 |
| Grant date | Sep 1, 1992 |
| Priority date | — |
| Expiry date | May 21, 2010 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/163
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A range selecting impedance is switched into or out of a parallel range-selecting network by connecting the impedance across the network through an n-channel and a p-channel FET connected in parallel output configuration. The n-channel FET does the switching if the drains are negative with respect to the sources. The p-channel FET does the switching if the drains are positive with respect to the sources. Each FET is controlled by a gate drive whose output waveform is varied to select the rate at which the FETs switch. In cases of several different switched range impedances, the FETs are used to switch the smallest impedance into the network, another range impedance is selected, and then the FETs used to switch the smallest impedance out of the network. In this way, fast glitch-free range switching is achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.