GENERAL DESCRIPTION

The ML9212 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 32-segment driver multiplexed to drive up to 96 segments, and 10-bit digital dimming circuit.

ML9212 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.

ML9212 provides an interface with a microcontroller only by three signal lines: DATA IN, CLOCK and CS.

FEATURES

• Logic supply voltage (VDD) : 4.5 to 5.5 V

• Driver supply voltage (VDISP) : 8 to 18 V

• Duplex/Triplex (1/2 duty / 1/3 duty) selectable

DUP/TRI = 1/2 duty selectable at “H” level

DUP/TRI = 1/3 duty selectable at “L” level

• Number of display segments

Max. 64-segment display (during 1/2 duty mode)

Max. 96-segment display (during 1/3 duty mode)

• Master/Slave selectable

M/S = Master mode selectable at “H” level

M/S = Slave mode selectable at “L” level

• Interface with a microcontroller

Three lines: CS, CLOCK, and DATA IN

• 32-segment driver outputs : IOH = –5 mA at VOH = VDISP–0.8 V (SEG1 to 22)

(can be directly connected to VFD tube : IOH = –10 mA at VOH = VDISP–0.8V (SEG23 to 32)

and require no external resisters) : IOL = 500 µA at VOL = 2 V (SEG1 to 32)

• 3-grid pre-driver outputs : IOH = –5.0 mA at VOH = VDISP–0.8 V

(require external drivers) IOL = 10 mA at VOL = 2 V

• Logic outputs : IOH = –200 µA at VOH = VDD–0.8 V

IOL = 200 µA at VOL = 0.8 V

• Built-in digital dimming circuit (10-bit resolution)

• Built-in oscillation circuit (external R and C)

• Built-in Power-On-Reset circuit

• Package options:

56-pin plastic QFP (QFP56-P-910-0.65-2K)(ML9212GA)