The ML9211 is a full CMOS controller/driver for Duplex or Triplex (1/2 duty or 1/3 duty) vacuum fluorescent display tube. It consists of a 56-segment driver multiplexed to drive up to 168 segments, and 10-bit digital dimming circuit. ML9211 features a selection of a master mode and a slave mode, and therefore it can be used to expand segments for the VFD driver with keyscan and A/D converter function. ML9211 provides an interface with a microcontroller only by three signal lines: DATA IN, CLOCK and CS.