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A Vacuum-Fluorescent-Display (VFD) consists of grids and anodes which are needed for driving the segments. In addition there is also a heating which needs a DC or AC voltage, this depends on the type of the VFD. Without heating the VFD can't operate. A segment of a VFD is activated by applying a voltage (from ca. 12V upwards) on the grid and the anode of this segment. Mostly VFDs are driven multiplexed which means that the grids are activated one after another and through the anodes the display segments can be activated. There are also VFDs that work non-multiplexed, so they have an own anode for each display segment.
The MSC1162A from OKI Semiconductor can drive directly the grids and anodes of a VFD. This circuit has 40 output ports, display data is clocked in serially into the internal shift register. After a latch impulse the shifted data appears at the output ports. The maximum supply voltage for the output drivers is 65V. Several circuits can also be cascaded by connecting the data output line to the data input line of the following circuit.
The MSC1163 from OKI Semiconductor is a 40-Bit anode driver. Data is transferred to the circuit in the same way as at the MSC1162A. Cascading several circuits is also possible, even MSC1162A circuits can be connected.
The SED2020 from S-MOS Systems can drive up to 20 grids or anodes of a VFD. The output ports are divided into two blocks of 10 ports. Each block has its own serial interface. Display data is clocked in serially and stored after a latch impulse. Several circuits can be cascaded by connecting the data output line to the data input line of the following circuit.
The SED2032 from S-MOS Systems differs from the SED2020 only in the number of output ports: it can drive 32 anodes or grids. The output ports are divided into two blocks of 16 ports.
· Information around LC-Displays
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