Integrated semiconductor resistor ladder for A=D or D=A converter - has pair of serially connected MOS-transistors having common contact port connected in parallel across each resistor

摘要

The resistive ladder includes several resistors (3-18) connected in series between a ground connection (1) and a supply connection (2). A voltage at the connecting joints of the resistors is selected with MOS transistors (19 and 23, 20 and 24, 21 and 25, 22 and 26). The MOS transistors are serially connected in pairs with a common contact port. Each pair is connected with each pair of adjacent connecting joints of the resistors. The connected parts of the MOS transistors are connected commonly with an output line (35). The output line crosses a resistor between the pair of connecting joints. ADVANTAGE - Has reduced layout area.