Clamping circuit and method for clamping a voltage
US5986493A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 28, 1997 |
| Grant date | Nov 16, 1999 |
| Priority date | — |
| Expiry date | Oct 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K5/08
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A clamping circuit (100) is provided for controlling an external switch, using a control signal, in response to monitoring a voltage at a first node. When the voltage at the first node exceeds a certain voltage, the clamping circuit (100) closes the external switch to complete a current path to reduce the voltage at the first node. The clamping circuit (100) includes a voltage divider circuit, a first device, a second device, a current mirror circuit, and a switch. The voltage divider circuit, which may be implemented using a resistor (30) and a resistor (32), is coupled between the first node and a fourth node and generates a divider voltage at a third node that is proportional to the voltage at the first node. The first device and the second device may be implemented using a first bipolar junction transistor (38) and a second bipolar junction transistor (40), respectively. The first device receives the divider voltage and generates a first current, and the second device receives the divider voltage and generates a second current in response. The current mirror circuit receives the first current and mirrors the first current to the second device where a reference signal is generat…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.