| 摘要 |
A bandgap voltage reference circuit is achieved that does not resort to the use of resistors or regulation loops and is thus able to achieve improved noise performance while also exhibiting absolute stability, no start-up issues, and low input-voltage operation. Subcircuits comprised of four interconnected transistors of different junction areas are used to create differential base-emitter voltage sources with magnitudes that vary in direct proportion to absolute temperature. The voltages from several of these subcircuits are combined without resistors to create a voltage source that is proportional to absolute temperature. An additional transistor is operated as a forward-biased PN junction to create a voltage source that varies in a sense that is complementary to absolute temperature. By a judicious choice of the transistor-junction-area ratios and the number of subcircuits that are summed, the combination of the complementary and proportional voltage references produces a bandgap voltage reference that is nearly constant with variations in temperature. The unique summation technique presented results in a bandgap reference with a noise performance that is more than an order of magnitude better than the prior art, particularly for applications requiring low current consumption.
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