Patent ID: 8922190

Claim:
A band gap reference voltage generator, comprising: first and second forward-biased PN junction elements of different current densities; a first current conduction path between a first node and a second node, including a plurality of first resistive elements that are connected in series between said first node and a third node, and said first PN junction element that is connected in series between said third node and said second node, wherein said first resistive elements are connected in a voltage divider configuration, wherein said plurality of first resistive elements includes a plurality of resistive trim elements having a ladder of 2n trim resistors of value R, a plurality of connector elements connecting said resistive trim elements in series, a first resistor having a resistance of R 1 -nR connected in series between the first node and the plurality of resistive trim elements, and a second resistor having a resistance of R 2 -nR connected in series between the third node and the plurality of resistive trim elements, wherein the n is a natural number; a tap connected selectively to said first resistive elements through switch elements, wherein the switch elements are controllable to select a voltage divider ratio at said tap; a second current conduction path between said first and second nodes, including a second resistive element connected in series between said first node and a fourth node, and said second PN junction element that is connected in series between said fourth node and said second node; a voltage error amplifier having a first input connected to said tap, a second input connected to said fourth node, and an output for providing a thermally compensated output voltage; and a feedback path for applying said output voltage to a series connection of a third resistive element with said first and second nodes.