Temperature independent low voltage reference circuit
US7279880B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 29, 2004 |
| Grant date | Oct 9, 2007 |
| Priority date | — |
| Expiry date | Apr 13, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/245
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A temperature independent low voltage reference circuit comprises a first transistor with a threshold voltage Vth having a negative temperature coefficient. A diode having a forward voltage drop with a negative temperature coefficient coupled with its anode connected to the drain of the first transistor and its cathode connected to the gate of the first transistor. A first resistor coupled between a power supply terminal and the drain of the first transistor. A low voltage supply terminal connected to the source of the first transistor. A second resistor coupled between the gate of the first transistor and the low voltage supply terminal. The drain of the first transistor provides a voltage with a negative temperature coefficient equal to the sum of the forward voltage drop across the diode and the threshold voltage of the first transistor. A circuit providing a voltage with a positive temperature coefficient is coupled between the drain of the first transistor and the low voltage supply terminal and has an output terminal. The positive temperature coefficient balances said negative temperature coefficient so that the voltage at said output has a temperature coefficient of zero.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.