Patent ID: 7385544

Claim:
A multi-reference voltage generator, comprising: an interface controller having a serial data input and a parallel data output; a first bank of N m-bit registers, said first bank of registers having a parallel data input connected to said parallel data output of said interface controller, where N is an integer ≧2, and m is integer ≧2; a second bank of N m-bit registers, said second bank of registers also having a parallel data input connected to said parallel data output of said interface controller; a first multiplexer having inputs connected to outputs of said first bank of registers and outputs of said second bank of registers; an m-bit digital-to-analog (DAC) having an m-bit parallel input connected to an output of said first multiplexer; an analog demultiplexer having an input connected to an analog output of said-bit DAC; a first group of N sample-and-hold (S/H) circuits, wherein each S/H circuit in said first group is connected to a corresponding output of said analog demultiplexer; a second group of N sample-and-hold (S/H) circuits, wherein each S/H circuit in said second group is connected to a corresponding output of said analog demultiplexer; N further multiplexers, each of which has a first input connected to an output of a corresponding one of said S/H circuits in said first group and a second input connected to an output of a corresponding one of said S/H circuits in said second group; and N output buffers, each of which has an input connected to an output of a corresponding one of said N further multiplexers, and an output useful for driving a column driver; wherein said second bank of registers is written to while data in said first bank of registers is converted to analog voltages and stored in said first group of S/H circuits.