A 10-Bit DAC With 1.6-Bit Interpolation Cells for Compact LCD Column Driver ICs

Abstract

This paper proposes a 10-bit DAC for LCD column driver ICs. This architecture achieves 10-bit resolution with a compact die size smaller than that of a conventional 8-bit resistor-string DAC (RDAC). The proposed DAC combines a 6-bit RDAC and a 4-bit DAC-embedded op with 1.6-bit current-mode interpolation cells. The 6-bit RDAC uses a one-voltage selector instead of a two-voltage selector; therefore, it requires a smaller silicon die area for the voltage selector. Fewer differential pairs are required for the voltage interpolation because the DAC-embedded op uses 1.6-bit interpolation cells with binary-weighted reference voltages. This further reduces the silicon die area. The 10-bit DAC prototype was realized in 0.35-μm CMOS technology with the worst DNL/INL of 0.45/0.93 LSB. The 10-bit DAC occupies only 64% of the conventional 8-bit RDAC area.