MAXIM Integrated Products, represented by Arrow , has introduced the MAX6920, MAX6921 and MAX6931 vacuum-fluorescent display (VFD) drivers.
These devices interface a multiplexed or static VFD tube to a VFD controller or to a microcontroller.
The MAX6920 has 12 outputs while the MAX6921 and MAX6931 have 20 outputs, all which are rated to 76V and continuously source 40mA and sink 4mA.
The outputs can also source 75mA repetitive pulses. Any output can operate as a grid or anode driver, thus simplifying layout. Well-matched, push-pull CMOS outputs allow drivers to be paralleled together to supply additional current to larger grids.
Data is input through an industry-standard, 5MHz four-wire serial interface (CLK, DATA, LOAD, BLANK), and is compatible with existing VFD drivers and controllers.
Use BLANK to turn off the display and automatically put the device into shutdown mode. The display intensity may also be controlled by pulse-width modulating the BLANK input.
The MAX6920 and MAX6921 have a DOUT pin, which allows multiple devices to be cascaded on the same serial interface.
The MAX6931 has a negative grid-supply voltage input, Vss, which allows the drivers' output swing to be made bipolar to only the filament biasing, referencing it to GND.
The MAX6920 is available in a 20-pin SO package. The MAX6921 is available in 28-pin TSSOP, SO, and PLCC packages. The MAX6931 is available in a 28-pin TSSOP package.
All devices operate from a 3V to 5.5V logic supply over the automotive temperature range (-40°C to +125°C).