MC14521B 24-Stage Frequency Divider The MC14521B consists of a chain of 24 flipflops with an input circuit that allows three modes of operation. The input will function as a crystal oscillator, an RC oscillator, or as an input buffer for an external oscillator. Each flipflop divides the frequency of the previous flipflop 24 by two, consequently this part will count up to 2 = 16,777,216. The MC14521B BLOCK DIAGRAM RESET 2 STAGES STAGES 9 6 1 THRU 17 18 THRU 24 IN 1 IN 2 Q18 Q19 Q20 Q21 Q22 Q23 Q24 V = PIN 16 DD V = PIN 8 SS PIN ASSIGNMENT 5 4 3 7 10 11 12 13 14 15 1 V OUT2 DD OUT 1 V SS Q24 1 16 V DD RESET 2 15 Q23 Output Count Capacity 18 Q18 2 = 262,144 V 3 14 Q22 SS 19 Q19 2 = 524,288 OUT 2 4 13 Q21 20 Q20 2 = 1,048,576 21 Q21 2 = 2,097,152 V 5 12 Q20 DD 22 Q22 2 = 4,194,304 IN 2 6 11 Q19 23 Q23 2 = 8,388,608 24 Q24 2 = 16,777,216 7 10 Q18 OUT1 V 8 9 IN 1 SS ORDERING INFORMATION Device Package Shipping MC14521BCPG PDIP16 500 Units / Rail (Pb Free) MC14521BDG SOIC16 48 Units / Rail (Pb Free) NLV14521BDG* SOIC16 MC14521BDR2G 2500 / Tape & Reel (Pb Free) NLV14521BDR2G* For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging Specifications Brochure, BRD8011/D. *NLV Prefix for Automotive and Other Applications Requiring Unique Site and Control Change Requirements AECQ100 Qualified and PPAP Capable.