Differential transistor pair current switch supplied by a low voltage VCC
US7671637B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jun 6, 2006 |
| Grant date | Mar 2, 2010 |
| Priority date | — |
| Expiry date | Jun 6, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K2217/0036
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
The invention relates to current switches using a differential pair of transistors and being able to operate under a low supply voltage Vcc. According to the invention, provision is made for the current switch to include two differential pairs of two transistors each (T1, T1b; T2, T2b), cascaded together, the second pair (T2, T2b) having complementary current outputs (H, Hb) that flip according to the states of the inputs (E, Eb). The first pair (T1, T1b) is connected to a ground (GND) through a current source, supplying a current of value Io and comprising a transistor (Ts1) biased by a voltage Vbias, and it is supplied by a voltage equal to N·Vbe+Vbias, where N is a whole number (preferably equal to 1) and Vbe is the base-emitter voltage of the transistor (Ts1). The second pair (T2, T2b) is connected to ground directly through a resistance (R2). The invention can be applied to the on-off control of sample-and-hold circuits, multiplexers, fast low-voltage logic circuits, etc.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.