PHILIPS PCF1171C 4-digit LCD car clock handbook

PCF1171C is a single chip, 4.19 MHz CMOS car clock circuit indicating hours and minutes. It is designed to drive a 31/2 or 4-digit liquid crystal display (LCD). Two external single-pole, single-throw switches will accomplish all time setting functions. The circuit is battery-operated via an internal 5 V voltage regulator or by an external stabilized voltage supply.