Design methods for CMOS low-current finely tunable voltage references covering a wide output range

This paper introduces methods that were used to design a 0.25 μm CMOS low-current tight-tolerance shunt voltage reference circuit. It shows how a recently reported method to produce laser tuned diffused resistors can be applied to the design of continuously tunable voltage references. The methods are validated with a prototype integrated circuit. Measured results show that the output voltage is continuously tunable, from 1.241V to 2.048V, at 0.05% accuracy. The design occupies 0.43 mm² and has a quiescent current of 10 μA.