Arrangement for improving the longterm stability of a Hall element
US4970411A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 19, 1989 |
| Grant date | Nov 13, 1990 |
| Priority date | — |
| Expiry date | Apr 19, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L2924/0002
Abstract
An arrangement which eliminates or reduces the negative influence of small variations in the charge-carrier concentration of a semiconductor material upon the longterm stability of a magnetic field sensor such as a Hall element is disclosed. In an illustrative embodiment, the arrangement comprises a magnetic field sensor, a voltage/current converter which provides a supply current to the magnetic field sensor, an amplifier connected sequentially downstream of the voltage/frequency converter, and an analog/digital or voltage/frequency converter connected sequentially downstream of the amplifier. The amplifier provides a transmission ratio which is proportional to (1+.delta.n/n) or (1-.delta.n/n) where n is the carge-carrier concentration of the semiconductor material in which the magnetic field sensor is formed and .delta.n is a variation in time of the charge-carrier concentration n. The amplifier comprises an inverting amplifier which is formed using an operational amplifier, a feedback resistor and an input resistor. The amplification factor of the amplifier is proportional to the ratio of the resistance values of the two resistors which are incorporated by diffusion in a semicon…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.