WO1982002964A1 - Variable temperature coefficient level shifter - Google Patents
Variable temperature coefficient level shifter Download PDFInfo
- Publication number
- WO1982002964A1 WO1982002964A1 PCT/US1982/000100 US8200100W WO8202964A1 WO 1982002964 A1 WO1982002964 A1 WO 1982002964A1 US 8200100 W US8200100 W US 8200100W WO 8202964 A1 WO8202964 A1 WO 8202964A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- temperature coefficient
- current
- voltage
- generating
- supply voltage
- Prior art date
Links
- 238000000034 method Methods 0.000 claims description 5
- 230000008878 coupling Effects 0.000 claims 1
- 238000010168 coupling process Methods 0.000 claims 1
- 238000005859 coupling reaction Methods 0.000 claims 1
- 238000010420 art technique Methods 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05F—SYSTEMS FOR REGULATING ELECTRIC OR MAGNETIC VARIABLES
- G05F3/00—Non-retroactive systems for regulating electric variables by using an uncontrolled element, or an uncontrolled combination of elements, such element or such combination having self-regulating properties
- G05F3/02—Regulating voltage or current
- G05F3/08—Regulating voltage or current wherein the variable is dc
- G05F3/10—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics
- G05F3/16—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices
- G05F3/20—Regulating voltage or current wherein the variable is dc using uncontrolled devices with non-linear characteristics being semiconductor devices using diode- transistor combinations
- G05F3/30—Regulators using the difference between the base-emitter voltages of two bipolar transistors operating at different current densities
Definitions
- This invention relates generally to a voltage level shifter and, more particularly, to a circuit for generating a voltage having an independently controllable temperature coefficient and amplitude.
- a level shifting circuit for producing an output voltage having a desired amplitude and temperature coefficient, comprising: a first supply voltage terminal; a second supply voltage terminal; a first current source coupled to said first supply voltage terminal for generating a first current having a positive temperature coefficients a second current source coupled to said first supply voltage terminal for generating a second current having a negative temperature coefficient; and first resistive means coupled between said first and second current sources and said second supply voltage terminal for combining, said first and second currents to produce a third current having a net temperature coefficient corresponding to said desired temperature coefficient and for generating from said third current a voltage having said net temperature coefficient, said voltage having said desired amplitude.
- a method for level shifting a voltage comprising: generating a first current having a positive temperature coefficient; generating a second current having a negative temperature coefficient; varying the magnitude of said first and second currents to achieve a net negative, zero, or positive temperature coefficient; and applying the sum of said first and second currents to a first resistive means the resistance of which being chosen to produce a required level shift.
- the inventive arrangement shown in the drawing includes first and second resistors R N and R P coupled between ground and nodes 4 and 6 respectively.
- a third resistor R S is coupled to a source of supply voltage (V+) and to node 2 from which the circuit output is taken.
- Block 8 which is coupled to nodes 2, 4, and 6 as shown includes circuitry for generating a first voltage V BE and a second voltage ⁇ V BE , V BE corresponding to the base-emitter voltage of a transistor and having a negative temperature coefficient, and ⁇ V BE being the base-toemitter voltage differential between a pair of transistor and having a positive temperature coefficient. Circuits for generating these voltages are well-known and a further description is not deemed necessary here.
- Resistors R N , R P and R S may be internal to an integrated circuit chip or external thereto.
- V BE appearing at node 4
- the current flowing through R N has a negative temperature coefficient and a value of V BE /R N .
- ⁇ V BE appearing at node 6
- the current flowing through R P has a positive temperature coefficient associated therewith and a value of ⁇ V BE /R P .
- the total current flowing through resistor R S (I CNT equals V BE /R N plus ⁇ V BE /R P ). This current has a net temperature coefficient associated with it which is controlled by properly selecting resistors Rpj and R P .
- the temperature coefficient of I CNT is totally due to the ⁇ V BE component and is therefore positive. If, on the other hand, R P is open, the temperature coefficient of I CNT is due to the V BE term and is therefore negative.
- the temperature coefficient of I CNT may be varied from approximately -2800 parts-per-million to +3000 parts-per-million.
- the magnitude of the level shift appearing at node 2 can be set to some desired magnitude by properly selecting resistor R S .
- the voltage drop across R S will now have the same temperature coefficient associated therewith as was imparted to the control current I CNT .
- a voltage source has been created which has a controllable temperature coefficient and an independently controlled magnitude. That is, temperature coefficient is controlled by selecting R N and R P , and the magnitude of the shift is controlled by selecting R S .
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Physics & Mathematics (AREA)
- Power Engineering (AREA)
- Nonlinear Science (AREA)
- Electromagnetism (AREA)
- General Physics & Mathematics (AREA)
- Radar, Positioning & Navigation (AREA)
- Automation & Control Theory (AREA)
- Logic Circuits (AREA)
- Control Of Electrical Variables (AREA)
- Amplifiers (AREA)
Abstract
A variable temperature coefficient level shifter includes a circuit which generates a voltage V<uBE>u having a negative temperature coefficient and a voltage //c V<uBE>u having a positive temperature coefficient. A control current is generated by placing a first resistor (R<uN>u) between V<uBE>u and ground and a second resistor (R<up>u) between //c V<uBE>u and ground. Each of these currents forms a component of the control current which then has some net temperature coefficient. By properly scaling the resistors the control current may have any desired temperature coefficient between 2800ppm and 3000ppm. Once the temperature coefficient is set, a third resistor (R<uS>u) is provided through which the control current flows. The amplitude of the shift is then selected by selecting the value of resistor (R<uS>us).
Description
VARIABLE TEMPERATURE COEFFICIENT LEVEL SHIFTER
Background of the Invention
Field of the Invention:
This invention relates generally to a voltage level shifter and, more particularly, to a circuit for generating a voltage having an independently controllable temperature coefficient and amplitude.
Description of the Prior Art:
The need often arises to provide an output current or voltage having a zero temperature coefficient, and circuits for accomplishing this are well-known. For example, reference is made to U.S. Patent 3,887,863 entitled "Solid-State Regulated Voltage Supply", U.S. Patent 3,617,859 entitled "Electrical Regulator Apparatus Including A Zero Temperature Coefficient Voltage Reference Circuit", and U.S. Patent 3,893,018 entitled "Compensated Electronic Voltage Source". Such circuits generally offset the negative temperature coefficient of a base-to-emitter voltage (VBE) of one transistor with a positive temperature coefficient derived from the base-to-emitter voltage differential (ΔVBE) between a pair of transistors. One of the problems associated with this prior art technique is that the amount of negative temperature coefficient that may be introduced into the output is severely restricted by a single VBE.
Summary of the Invention
It is an object of the present invention to provide a voltage level shifting circuit having a controllable temperature coefficient and which produces a stable independently controllable level shifting voltage amplitude.
It is a further object of the present invention to provide a voltage level shifting circuit having a controllable temperature coefficient and an independently controllable shift amplitude which is not affected by circuitry coupled to its output or otherwise associated therewith.
It is still further object of the invention to provide a voltage level shifting circuit having a controllable temperature coefficient and an independently controllable shift amplitude which does not require multiplying or the use of resistive voltage dividers.
According to a first aspect of the invention there is provided a level shifting circuit for producing an output voltage having a desired amplitude and temperature coefficient, comprising: a first supply voltage terminal; a second supply voltage terminal; a first current source coupled to said first supply voltage terminal for generating a first current having a positive temperature coefficients a second current source coupled to said first supply voltage terminal for generating a second current having a negative temperature coefficient; and first resistive means coupled between said first and second current sources and said second supply voltage terminal for combining, said first and second currents to produce a third current having a net temperature coefficient corresponding to said desired temperature coefficient and for generating from said third current a voltage having said net temperature coefficient, said voltage having said desired amplitude. According to a further aspect of the invention there is provided a method for level shifting a voltage, the amplitude of the level shift and the temperature coefficient thereof being independently controllable, comprising: generating a first current having a positive temperature coefficient; generating a second current having a negative temperature coefficient; varying the magnitude
of said first and second currents to achieve a net negative, zero, or positive temperature coefficient; and applying the sum of said first and second currents to a first resistive means the resistance of which being chosen to produce a required level shift.
Brief Description of the Drawings
The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawing in which the sole figure is a diagram, partially in block form and partially in schematic form, illustrating the invention.
Description of the Preferred Embodiment
The inventive arrangement shown in the drawing includes first and second resistors RN and RP coupled between ground and nodes 4 and 6 respectively. A third resistor RS is coupled to a source of supply voltage (V+) and to node 2 from which the circuit output is taken. Block 8 which is coupled to nodes 2, 4, and 6 as shown includes circuitry for generating a first voltage VBE and a second voltage ΔVBE, VBE corresponding to the base-emitter voltage of a transistor and having a negative temperature coefficient, and ΔVBE being the base-toemitter voltage differential between a pair of transistor and having a positive temperature coefficient. Circuits for generating these voltages are well-known and a further description is not deemed necessary here. However, the interested reader is referred to the above-cited U.S. Patent 3,887,863. Resistors RN, RP and RS may be internal to an integrated circuit chip or external thereto.
With VBE appearing at node 4, the current flowing through RN has a negative temperature coefficient and a value of VBE/RN. In like manner, with ΔVBE appearing at node 6, the current flowing through RP has a positive temperature coefficient associated therewith and a value of ΔVBE/RP. Thus, the total current flowing through resistor RS (ICNT equals VBE/RN plus ΔVBE/RP). This current has a net temperature coefficient associated with it which is controlled by properly selecting resistors Rpj and RP. For example, if RN is open (infinite impedance), the temperature coefficient of ICNT is totally due to the ΔVBE component and is therefore positive. If, on the other hand, RP is open, the temperature coefficient of ICNT is due to the VBE term and is therefore negative. Thus, by properly scaling RN and RP, the temperature coefficient of ICNT may be varied from approximately -2800 parts-per-million to +3000 parts-per-million.
Now that the temperature coefficient has been set to some desired value, the magnitude of the level shift appearing at node 2 can be set to some desired magnitude by properly selecting resistor RS. The voltage drop across RS will now have the same temperature coefficient associated therewith as was imparted to the control current ICNT. Thus, a voltage source has been created which has a controllable temperature coefficient and an independently controlled magnitude. That is, temperature coefficient is controlled by selecting RN and RP, and the magnitude of the shift is controlled by selecting RS.
Several advantages of the arrangement shown in the drawing should be noted. First, it is only the ratio of the resistors which sets the amplitude of the level shift and not the absolute values of the resistors. This reduces resistor tolerance requirements as long as the resistors are created using common resistor processing. For example,
if the values of RN and RP are high, the current will be low. However, since the value of RS will also be high, the resulting level shift remains the same. Second, the level shift voltage across resistor RS is constant regardless of fluctuations in the supply voltage V+.
The above description is given by way of example only. Changes in form and details may be made by one skilled in the art without departing from the scope of the invention.
Claims
1. A level shifting circuit for producing an output voltage. having a desired amplitude and temperature coefficient, comprising: a first supply voltage terminal; a second supply voltage terminal; a first current source coupled to said first supply voltage terminal for generating a first current having a positive temperature coefficient; a second current source coupled to said first supply voltage terminal for generating a second current having a negative temperature coefficient; and first resistive means coupled between said first and second current sources and said second supply voltage terminal for combining said first and second currents to produce a third current having a net temperature coefficient corresponding to said desired temperature coefficient and for generating from said third current a voltage having said net temperature coefficient, said voltage having said desired amplitude.
2. A circuit according to claim 1 wherein said first current source comprises: first means for generating a first voltage having a positive temperature coefficient; and second resistive means coupled between said first means and said first supply voltage terminal.
3. A circuit according to claim 2 wherein said second current source comprises: second means for generating a voltage having a negative temperature coefficient; and third resistive means coupled between said second means and said first supply voltage terminal.
4. A circuit according to claim 3 wherein said second current corresponds to the base emitter voltage of a transistor and wherein said first current corresponds to the base-emitter voltage differential of a pair of transistors.
5. A level shifting circuit for coupling to a first source of a first voltage having a positive temperature coefficient and to a second source of a second voltage having a negative temperature coefficient for the purpose of producing a voltage having a desired temperature coefficient and amplitude, comprising: a first supply voltage terminal; a second supply voltage terminal; first resistive means adapted to be coupled between said first supply voltage terminal and said first source for generating a first current having a positive temperature coefficient; second resistive means adapted to be coupled between said first supply voltage terminal and said second source for generating a second current having a negative temperature coefficient; and third resistive means adapted to be coupled between said second supply voltage terminal and said first and second sources for combining said first and second currents to produce a third current having a net temperature coefficient and for generating therefrom a voltage having a desired amplitude and temperature coefficient.
6. A method for providing controllable voltage level shift having an independently controllable temperature coefficient, comprising: generating a first voltage having a positive temperature coefficient;
generating a second voltage having a negative temperature coefficient; applying said first and second voltages across first and second resistive means the values of which are chosen to result in a current having a desired net temperature coefficient; and applying said total current to a third resistive means the resistance of which determines said voltage level shift.
7. A method according to claim 6 further including: varying said first and second resistive means to varying said net temperature coefficient; and varying said third resistive means to alter said level shift.
8. A method according to claim 7 wherein said net temperature coefficient may be varied from approximately -2800 parts per million to approximately +3000 parts per million.
9. A method for level shifting a voltage, the amplitude of the level shift and the temperature coefficient thereof being independently controllable, comprising: generating a first current having a positive temperature coefficient; generating a second current having a negative temperature coefficient; varying the magnitude of said first and second currents to achieve a net negative, zero, or positive temperature coefficient; and applying the sum of said first and second currents to a first resistive means the resistance of which, being chosen to produce a required level shift.
Priority Applications (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP57500778A JPH0664504B2 (en) | 1981-02-20 | 1982-01-25 | Level shift circuit |
JP50114382A JPS58500558A (en) | 1981-04-06 | 1982-03-31 | Barge transport vessels and barge loading methods |
JP50155682A JPS59500809A (en) | 1981-05-11 | 1982-05-11 | Container safety closure equipment |
JP50187082A JPS58501007A (en) | 1981-06-22 | 1982-06-17 | Central heating methods and equipment |
JP50184682A JPS58500968A (en) | 1981-06-23 | 1982-06-21 | Pressure adjustment dripping device |
JP50250982A JPS58501583A (en) | 1982-01-25 | 1982-08-25 | Display device for parameters of diving operations |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US23609181A | 1981-02-20 | 1981-02-20 | |
US236091810220 | 1981-02-20 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1982002964A1 true WO1982002964A1 (en) | 1982-09-02 |
Family
ID=22888107
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1982/000100 WO1982002964A1 (en) | 1981-02-20 | 1982-01-25 | Variable temperature coefficient level shifter |
Country Status (4)
Country | Link |
---|---|
EP (1) | EP0072842A4 (en) |
JP (1) | JPH0664504B2 (en) |
IT (1) | IT1147597B (en) |
WO (1) | WO1982002964A1 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990015378A1 (en) * | 1989-06-08 | 1990-12-13 | Analog Devices, Inc. | Band-gap voltage reference with independently trimmable tc and output |
WO2001029633A1 (en) * | 1999-10-20 | 2001-04-26 | Telefonaktiebolaget Lm Ericsson | Electronic circuit |
Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US30586A (en) * | 1860-11-06 | Dooe-lock | ||
US3781648A (en) * | 1973-01-10 | 1973-12-25 | Fairchild Camera Instr Co | Temperature compensated voltage regulator having beta compensating means |
US4079308A (en) * | 1977-01-31 | 1978-03-14 | Advanced Micro Devices, Inc. | Resistor ratio circuit construction |
JPS5574615A (en) * | 1978-11-30 | 1980-06-05 | Toshiba Corp | Constant voltage circuit |
US4263519A (en) * | 1979-06-28 | 1981-04-21 | Rca Corporation | Bandgap reference |
US4317054A (en) * | 1980-02-07 | 1982-02-23 | Mostek Corporation | Bandgap voltage reference employing sub-surface current using a standard CMOS process |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
FR2339719A1 (en) * | 1976-01-28 | 1977-08-26 | Strathclyde Precast Concrete L | Heat insulating block coating system - uses multiple mould with coatings applied by brushing and spraying |
JPS564817A (en) * | 1979-06-25 | 1981-01-19 | Hitachi Ltd | Constant voltage generating circuit |
DE3006598C2 (en) * | 1980-02-22 | 1985-03-28 | Robert Bosch Gmbh, 7000 Stuttgart | Voltage source |
-
1982
- 1982-01-25 WO PCT/US1982/000100 patent/WO1982002964A1/en not_active Application Discontinuation
- 1982-01-25 JP JP57500778A patent/JPH0664504B2/en not_active Expired - Lifetime
- 1982-01-25 EP EP19820900756 patent/EP0072842A4/en not_active Withdrawn
- 1982-02-08 IT IT47745/82A patent/IT1147597B/en active
Patent Citations (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US30586A (en) * | 1860-11-06 | Dooe-lock | ||
US3781648A (en) * | 1973-01-10 | 1973-12-25 | Fairchild Camera Instr Co | Temperature compensated voltage regulator having beta compensating means |
US4079308A (en) * | 1977-01-31 | 1978-03-14 | Advanced Micro Devices, Inc. | Resistor ratio circuit construction |
JPS5574615A (en) * | 1978-11-30 | 1980-06-05 | Toshiba Corp | Constant voltage circuit |
US4263519A (en) * | 1979-06-28 | 1981-04-21 | Rca Corporation | Bandgap reference |
US4317054A (en) * | 1980-02-07 | 1982-02-23 | Mostek Corporation | Bandgap voltage reference employing sub-surface current using a standard CMOS process |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO1990015378A1 (en) * | 1989-06-08 | 1990-12-13 | Analog Devices, Inc. | Band-gap voltage reference with independently trimmable tc and output |
WO2001029633A1 (en) * | 1999-10-20 | 2001-04-26 | Telefonaktiebolaget Lm Ericsson | Electronic circuit |
US6310510B1 (en) | 1999-10-20 | 2001-10-30 | Telefonaktiebolaget Lm Ericsson (Publ) | Electronic circuit for producing a reference current independent of temperature and supply voltage |
Also Published As
Publication number | Publication date |
---|---|
EP0072842A1 (en) | 1983-03-02 |
JPH0664504B2 (en) | 1994-08-22 |
IT8247745A0 (en) | 1982-02-08 |
IT1147597B (en) | 1986-11-19 |
JPS58500092A (en) | 1983-01-13 |
EP0072842A4 (en) | 1984-04-06 |
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