Abstract:
PROBLEM TO BE SOLVED: To provide a simple and economical digital potentiometer which has improved linearity and a shortened setting time when the resistance is changed by switching. SOLUTION: This potentiometer is equipped with plural 1st switches connected to a 1st input node, plural 2nd switched connected to a 2nd input node, plural 3rd switches connected to an output node, and 1st, 2nd, and 3rd strings of series-connected resistors; and the 1st string is connected between the 1st string and 2nd string, the 1st switches between the 1st input node and the 1st string of the resistors, the 2nd switches between the 2nd input node and the 2nd string of the resistors, and the 3rd switches between the output node and the 3rd string of the resistors.
Abstract:
A digitally switched impedance has improved linearity by minimizing the amount of impedance error introduced by switches used to switch the impedance elements comprising the digitally switched impedance. Improved settling time of the digitally switched impedance is achieved by reducing the amount of switch capacitance connected to the output of the digitally switched impedance. The digitally switched impedance may be fabricated on an integrated circuit die and the switches may be fabricated with complementary metal oxide semiconductor (CMOS) transistors. The number of impedances needed for a desired number of impedance step changes is reduced by using two major impedance ranks and one minor impedance rank, or two minor impedance ranks and one major impedance rank connected in series.
Abstract:
A digitally switched impedance has improved linearity by minimizing the amount of impedance error introduced by switches used to switch the impedance elements comprising the digitally switched impedance. Improved settling time of the digitally switched impedance is achieved by reducing the amount of switch capacitance connected to the output of the digitally switched impedance. The digitally switched impedance may be fabricated on an integrated circuit die and the switches may be fabricated with complementary metal oxide semiconductor (CMOS) transistors. The number of impedances needed for a desired number of impedance step changes is reduced by using two major impedance ranks and one minor impedance rank, or two minor impedance ranks and one major impedance rank connected in series.