DA converter and liquid crystal driving device incorporating the same

Abstract

A DA converter is for converting N-bit digital signals to 2N analog signals, and includes a reference voltage generating circuit for generating the reference voltages having 2A+1 voltage levels, a reference voltage selector circuit for selecting two reference voltages having adjacent voltage levels according to the A bits of a digital signal, an output voltage selector circuit for selecting one interpolation voltage from 2N-A−1 interpolation voltages predetermined between the voltage levels of the two reference voltages in accordance with the N-A bits of the digital signal, and a voltage follower circuit for producing the above interpolation voltage by linear interpolation based on the two reference voltages. With this structure, in a DA converter and a liquid crystal driving device incorporating the DA converter, despite a possible increase in the number of voltages required for a display with more gradation levels, large increases in the number of circuit composing elements can be avoided, thus preventing an increase in manufacturing cost and permitting the production of more compact devices.

Dependencies are inferred from the claim text.