| This thesis discusses one class of the nonbandgap voltage references based on threshold-voltage-difference architecture.; The considered voltage references exploit weak temperature dependence of the difference of MOS transistor threshold voltages. This difference is nearly constant across a wide range of temperatures -20 to 120°C. This fact is used to design voltage references with a low power supply voltage (below 0.8 V) in modern 0.18-micron CMOS technology. The theoretical investigation and simulations show that their temperature operation range is very wide (-25 to 125°C), and the power supply voltage may change simultaneously from 1.8 V down to 0.6 V. The variation of the output voltage in this temperature range and power supply range is as low as 0.7%. The references have a simple schematic and may be easily designed.; The practical realization of these references was, in out case, limited by the availability of devices realizable as a CMC multi-project university chip. In these chips only n- and p-channel regular and n-channel native (or so-called "natural") transistors are available. The thesis outlines the theory of considered voltage references, and gives the results of simulation of two representative examples of these references. At the time of writing, two reference circuits have been submitted to CMC for fabrication, and the chips will arrive in January 2006 for testing and measurements. |
