The MAX6921AQI+ is a 20 output, 76V, serial interfaced VFD tube driver in 28 pin PLCC package. It is a 20 output, 76V, vacuum fluorescent display (VFD) tube driver that interface a multiplexed VFD tube to a VFD controller such as the MAX6850 and MAX6853 or to a microcontroller. The MAX6921 also ideal for driving static VFD tubes or telecom relays. Data is input using an industry standard 4 wire serial interface (CLOCK, DATA, LOAD, BLANK) compatible with either Maxim's or industry standard VFD driver and controller. For easy display control, the active high BLANK input forces all driver outputs low, turning the display off and automatically puts the MAX6921 into shutdown mode. Display intensity can also be controlled by directly pulse width modulating the BLANK input. The MAX6921 has a serial interface data output DOUT allowing any number of devices to be cascaded on the same serial interface.