CD4055BE

The CD4055BE is a CMOS BCD-to-7-segment LCD Decoder/Driver with display-frequency output. This circuit provides level-shifting functions on the chip. This feature permits the BCD input-signal swings (VDD to VSS) to be the same as or different from the 7-segment output-signal swings (VDD to VEE). For example, the BCD input-signal (VDD to VSS) may be as small as 0 to 3V, whereas the output-display drive-signal swing (VDD to VEE) may be as large as from 0 to 15V. If VDD to VEE exceeds 15V, VDD to VSS should be at least 4V. The 7-segment outputs are controlled by the DISPLAY-FREQUENCY (DF) input which causes the selected segment outputs to be low, high or a square-wave output (for liquid-crystal displays). When the DF input is low the output segments will be high when selected by the BCD inputs. When the DF input is high, the output segments will be low when selected by the BCD inputs.

• Operation of liquid crystals with CMOS circuits provides ultra-low-power displays
• Equivalent ac output drive for liquid-crystal displays no external capacitor required
• Low or high-output level dc drive for other types of displays
• On-chip logic-level conversion for different input- and output-level swings
• 100% Tested for quiescent current at 20V

Applications

Clock & Timing, Metering