Reference voltage generator using two fine resistor ladders
AssigneeFujitsu Limited
InventorsKatsuyoshi Yamamoto, Toshitaka Mizuguchi
Life of this patent
Estimating the term…
Abstract
A reference voltage generator circuit generates a stable reference voltage that may be used by other circuits, such as an A/D converter and a D/A converter. The reference voltage generator circuit includes a rough resistor bank having a pair of first resistors connected in series between a low potential reference voltage and a high potential reference voltage. A first fine resistor bank is connected in shunt with one of the resistors in the rough resistor bank and a second fine resistor bank is also connected in shunt with the same resistor in the rough resistor bank. Switches are connected between nodes between the resistors in the fine resistor banks and another circuit or system, such as an A/D converter.
Claims8
A reference voltage generator circuit for delivering a reference voltage to a plurality of systems including a first system and a second system, comprising:
- a rough resistor bank including at least one resistor connected in series between a high potential side reference voltage and a low potential side reference voltage;
- a first fine resistor bank including a plurality of resistors connected in shunt with the at least one resistor of the rough resistor bank;
- a second fine resistor bank including a plurality of resistors connected in shunt with the at least one resistor in the rough resistor bank;
- a first group of switches connected between nodes between respective resistors in the first fine resistor bank and the first system;
- and
- a second group of switches connected between nodes between respective resistors in the second fine resistor bank and the second system.
Dependencies are inferred from the claim text.