Design And Realization Of Voltage Reference And Comparator

Voltage reference and comparator, which decide the performance of analogy Integration Circuit, are widely used in high-precision analogy IC designs. To design voltage reference and comparator with high performance is a long-term pursuit of analogy IC designers. In this paper, we analyze and design the two import circuits.Principle of the basic cells, which comprise the band-gap voltage reference (BGR) and comparator, is explained theoretically. Impact brought in by the un-ideal conditions is analyzed, and corresponding solutions are brought out. Realization technique of the temperature compensation and zero temperature coefficient is explained this paper. Two high-precision band-gap voltage references are designed, in which the amplifier is designed based on the miller compensation structure and the temperature compensation is realized through the co-operation of the circuits with positive and negative temperature coefficient. Circuits are simulated and verified in HSPICE and optimized according to the results. The designs are used in the power switch manager and the USB interface circuit. The result of the test after taping-out indicates that the performance has achieved the design requirement and is able to satisfy the given application circumstance.The reasons of DC offset and clock feed-through are analyzed, and pertaining solutions are brought out according to given application conditions. Two kinds of comparators are designed in this paper. First are a double of two-stage comparators, which have been made use of in power switch manager successfully. Secondly are two high-speed comparators, in which DC offset and clock feed-through effects are settled by the switched-capacitor theory and the restraining to the noise is achieved by the built-in hysteresis. Designs are simulated and verified in HSPICE and are optimized. They have been used in two 8-bit embedded ADC. One of the ADC has been taped-out and has been tested working correctly.