Patent ID: 9473097
Filing Date: 2016-10-18
CPC Classification: H03F,H03G

Claim Text:
1. A resistive ladder comprising: first, second, third, and fourth resistors coupled in series between first and second voltage terminals, the first and second resistors being coupled to each other by a first intermediate node, the second and third resistors being coupled to each other by a second intermediate node, and the third and fourth resistors being coupled to each other by a third intermediate node; a voltage selection unit having a first input coupled to the first intermediate node and a second input coupled to the second intermediate node, wherein said voltage selection unit is configured to selectively couple one of said first and second inputs to an output node of said resistive ladder; a first switch coupled between the third intermediate node and said second voltage terminal; and a control circuit configured to control the voltage selection unit and the first switch in a manner that a first resistance between the first intermediate node and the second voltage terminal when the first input node is selected to be coupled to the output node substantially equals a second resistance between the second intermediate node and the second voltage terminal when the second input node is selected to be coupled to the output node.