A programmable CMOS voltage reference based on a proportional summing circuit

This paper describes a new approach for design and implementation of programmable voltage reference based on current mode bandgap voltage reference and a proportional summing circuit. The circuit is simulated and fabricated with Chartered 0.35um mixed-signal technology, and our measurements demonstrate that its temperature coefficient is ±35.07ppm/°C from 0 to 100°C.The supply voltage is varied from 2.7–5V and the varied voltage reference is about 5mV. Depending on the state of the five VID inputs, an output voltage between 1.075V and 1.85V is programmed in 25mV increments.