STM86312 1/4 to 1/11-duty VFD controller/driver General features Many display modes (11 segments & 11 digits to 16 segments & 4 digits) Key scanning (6 x 4 matrix) Dimming circuit (eight steps) High-voltage output (V 35V max) DD LED ports (4 chs, 20mA max) General purpose input port (4 bits) No external resistor necessary for driver output PQFP44 (P-channel open drain + pull down resistor output) Serial interface (CLK, STB, D , D ) IN OUT Description The STM86312 is a VFD (Vacuum Fluorescent Display) controller/driver that is driven on a 1/4 to 1/11-duty factor. It consists of 11-segments output lines, 6 grid output lines, 5 segments/grid output drive lines, a display memory, a control circuit, and a key scan circuit. Serial data are input to the STM86312 through a three-line serial interface. This VFD controller/driver is ideal as a peripheral device for a single-chip microcomputer. Order codes Part number Temperature range Package Tube STM86312 -40 to 85 C PQFP44 Tray March 2006 Rev 2 1/24 www.st.com 24Contents STM86312 Contents 1 Block diagram 3 2 Pin settings 4 2.1 Pin connection 4 2.2 Pin description 5 3 Maximum rating . 6 3.1 Thermal data . 6 3.2 Recommended operating conditions . 6 4 Electrical characteristics . 8 5 Display RAM address and display mode . 10 6 LED port 12 7 SW data 13 8 Commands 14 8.1 Display mode setting command 14 8.2 Data setting command . 15 8.3 Address setting command 15 8.4 Display control command . 16 9 Serial communication format . 17 10 Application 19 11 Mechanical data 21 12 Revision history . 23 2/24