The HCC/HCF4543B is a BCD-to-seven segment latch/decoder/driver designed primarily for liquidcrystal display (LCD) applications. It is also capable of driving light emitting diode (LED), incandescent, gas-discharge, and fluorescent displays. This device is functionally similar to and serves as direct replacement for the HCF4056B when pin 7 is connected to VSS. It differs from the HCF4056B in that it has a display blanking capability instead of a level-shifting function and requires only one power supply. When the HCF4056B is used in the level shifting mode, two power supplies are required. When the HCF4543B is used for LCD applications, a square wave must be applied to the PHASE input and the backplane of the LCD device. For LED applications a logic 1 is required at the PHASE input for common-cathode devices ; a logic 0 is required for common-anode devices (see truth table). December 1989