DESCRIPTION

The HCC/HCF4543B is a BCD-to-seven segment latch/decoder/driver designed primarily for liquid crystal 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).

■ DISPLAY BLANKING OF ALL ILLEGAL INPUT COMBINATIONS

■ LATCH STORAGE OF CODE

■ CAPABILITY OF DRIVING TWO LOW POWER TTL LOADS, TWO HTL LOADS, OR ONE LOW POWER SCHOTTKY LOAD OVER THE FULL RATED-TEMPERATURE RANGE

■ PIN-FOR-PIN REPLACEMENT FOR THE HCF4056B (with pin 7 tied to VSS)

■ DIRECT LED DRIVING CAPABILITY

■ 100 TESTED FOR QUIESCENT CURRENT AT 20V MAXIMUM INPUT CURRENT OF 1A AT 18V OVER FULL PACKAGE-TEMPERATURE RANGE ; 100nA AT 18V AND 25°C

■ NOISE MARGIN (full package-temperature range) = 1V AT VDD = 5V

2V AT VDD = 10V

2.5V AT VDD = 15V

■ 5-V, 10-V, AND 15-V PARAMETRIC RATINGS

Applications :

■ INSTRUMENT DISPLAY DRIVER

■ DASHBOARD DISPLAY DRIVER

■ COMPUTER/CALCULATOR DISPLAY DRIVER

■ TIMING DEVICE DRIVER (clocks, watches, timers)