M74HC4543 is a high speed CMOS BCD-TO-7 SEGMENT DECODER WITH LCD DRIVER. It features high speed, low power dissipation, high noise immunity, symmetrical output impedance, balanced propagation delays and wide operating voltage range. The device consists of BCD-TO-7 segment decoder with a BCD input latch and a 7-segment driver for a liquid crystal display (LCD). When any illegal BCD input signal is applied or input BI is held high, the display is blanked. When driving LCDs, a common square wave signal should be applied not only to the PH input of this device but also to the electrically common backplane of the display. For other types of readouts, such as light-emitting diode (LED), some additional drivers, such as a transistor array is required. All inputs are equipped with protection circuits against static discharge and transient excess voltage.