Temperature independent current source
US5402061A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 13, 1993 |
| Grant date | Mar 28, 1995 |
| Priority date | — |
| Expiry date | Aug 13, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05F3/265
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
An improvement is provided for current sources of the type having three transistors configured as follows: The bases of the first (Q1) and second (Q2) transistors are tied together. The collector of the first transistor (Q1) is coupled to a first voltage (V.sub.CC,V.sub.EE) via a first resistor (R1). The emitter of the first transistor (Q1) is coupled to a second voltage (V.sub.EE,V.sub.CC) via a second resistor (R2). The collector of the second transistor (Q2) produces the output current (I.sub.OUT). The emitter of the second transistor (Q2) is coupled to the second voltage (V.sub.EE,V.sub.CC) via a third resistor (R3). The base of the third transistor (Q3) is coupled, either directly or indirectly through a fourth transistor (Q4), to the collector of the first transistor (Q1). The collector of the third transistor (Q3) is connected to the first voltage (V.sub.CC,V.sub.EE) and the emitter of that transistor (Q3) is connected to the bases of the first (Q1) and second (Q2) transistors. The improvement consists of a fourth resistor (R5) coupled between the base and the emitter of the first transistor (Q1), the fourth transistor preferably having a value that is one half of the value …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.