Low supply voltage analog disconnection envelope detector
US8829943B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Oct 19, 2012 |
| Grant date | Sep 9, 2014 |
| Priority date | — |
| Expiry date | Nov 30, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04B3/46
- WIPO fieldTelecommunications
- WIPO sectorElectrical engineering
Abstract
An analog disconnection envelope detection circuit having a low power supply detects a high speed, high differential voltage disconnect state on a data line. Level-shifting circuitry shifts the voltage level of two input signals by the value of a detection threshold voltage, generates differential signals used to indicate conditions of the input signals, and mitigates effects of input differential signal common-mode voltage on the detection operation. Circuitry is provided to equalize VDS of detecting tail current sources, thereby eliminating errors resulting from VDS mismatch of tail current sources. Comparator circuitry compares the sets of differential signals and indicates when the absolute difference between the two input signals is greater than a reference voltage. Output circuitry generates a disconnect signal corresponding to the disconnect condition. When compared to conventional disconnect detection circuitry, the disclosed circuit utilizes a relatively low supply voltage to detect high differential voltage disconnect conditions with improved accuracy.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.