Claims
- 1. A temperature compensated pre-regulator for generating a regulated voltage having a low temperature coefficient for use in generating a reference voltage, the pre-regulator comprising:
a current source; a first component coupled to the current source and which generates a first voltage having a negative temperature coefficient; and a second component coupled in series to said first component and to said current source and which generates a second voltage having a positive temperature coefficient, wherein said regulated voltage comprises a combination of said first and second voltages.
- 2. The pre-regulator of claim 1, wherein said first component comprises a VBE multiplier.
- 3. The pre-regulator of claim 1, wherein said second component comprises a proportional-to-absolute-temperature (PTAP) circuit.
- 4. The pre-regulator of claim 1, wherein said current source comprises a Wilson current source.
- 5. The pre-regulator of claim 1, further comprising feedback circuitry coupled to the current source for regulating the current flow therefrom directly in response to feedback from the reference voltage.
- 6. A circuit for generating a reference voltage, the circuit comprising:
(a) a temperature compensated pre-regulator for generating a regulated voltage having a low temperature coefficient, the pre-regulator including:
a current source; a first component coupled to the current source and which generates a first voltage having a negative temperature coefficient; and a second component coupled in series to said first component and to said current source and which generates a second voltage having a positive temperature coefficient, wherein said regulated voltage comprises a combination of said first and second voltages; (b) a VBE differential circuit coupled to the pre-regulator for generating a VBE differential voltage from the regulated voltage; and (c) output circuitry coupled to the VBE differential circuit for generating the reference voltage from the VBE differential voltage and a base-emitter voltage drop.
- 7. The circuit of claim 6, wherein the current source comprises a Wilson current source.
- 8. The circuit of claim 6, wherein said first component comprises a VBE multiplier.
- 9. The circuit of claim 6, wherein said second component comprises a proportional-to-absolute-temperature (PTAP) circuit.
- 10. The circuit of claim 6, wherein said VBE differential circuit is temperature compensated.
- 11. The circuit of claim 6, further comprising feedback circuitry coupled to the current source for regulating the current flow therefrom directly in response to feedback from the reference voltage, wherein the feedback circuitry comprises a feedback bipolar transistor.
- 12. The circuit of claim 6, wherein the output circuitry comprises an output bipolar transistor.
- 13. The circuit of claim 6, further comprising a start-up component coupled to the pre-regulator for drawing current from the current source at start-up.
- 14. The circuit of claim 13, wherein the start-up component includes a bipolar transistor biased by a resistor connected in series with a diode.
- 15. A method for providing a temperature compensated pre-regulated voltage for generating a reference voltage, the method comprising:
driving a current from a current source to a first component which generates a first voltage having a negative temperature coefficient; driving the current to a second component coupled in series to said first component and to said current source, wherein said second component generates a second voltage having a positive temperature coefficient; and combining the first and second voltage to provide the temperature compensated pre-regulated voltage.
- 16. The method of claim 15, wherein the act of driving a current into the first component includes driving the current with a Wilson current source.
- 17. The method of claim 15, wherein the act of generating a first voltage includes generating said voltage using a VBE multiplier.
- 18. The method of claim 15, wherein the act of generating a second voltage includes generating said voltage using a proportional-to-absolute-temperature (PTAP) circuit.
- 19. The method of claim 15 further comprising regulating the current in response to feedback from the reference voltage, wherein the act of regulating includes regulating said current using feedback circuitry coupled to the current source.
Priority Claims (1)
Number |
Date |
Country |
Kind |
99118480.7 |
Sep 1999 |
CN |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/643,171, filed Aug. 21, 2000 and entitled “Improved Bandgap Reference Circuit,” which is specifically incorporated herein by reference.
Continuations (1)
|
Number |
Date |
Country |
Parent |
09643171 |
Aug 2000 |
US |
Child |
09989221 |
Nov 2001 |
US |