Output high voltage clamped circuit for low voltage differential swing applications in the case of overload
US6005438A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 10, 1997 |
| Grant date | Dec 21, 1999 |
| Priority date | — |
| Expiry date | Dec 10, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/08142
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A low voltage differential swing circuit includes a clamping circuit to prevent the output high voltage from exceeding a reference voltage. The low voltage differential swing circuit also includes a current source coupled to a control node and a current steering circuit coupled between the control node and first and second output nodes. The current source provides a constant drive current, and in response to first and second input signals, the current steering circuit generates first and second drive currents, wherein the first and second drive currents together form at the first and second output nodes a differential output signal. The clamping circuit comprises a operational amplifier and a shunting circuit. The operational amplifier senses the difference between a reference voltage and a voltage level at the control node, which voltage level varies in relation to the voltage level of the differential output signal. When the voltage level at the control node transcends the reference voltage value, the excess drive current, or overload current, is shunted away from the first and second output nodes by the shunting circuit. Thus, the overload current is prevented from reaching the …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.