The MC14521B consists of a chain of 24 flip-flops 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 flip-flop divides the frequency of the previous flip-flop by two, consequently this part will count up to 2
= 16,777,216. The count advances on the negative going edge of the clock. The outputs of the last seven-stages are available for added flexibility.

• All Stages are Resettable
• Reset Disables the RC Oscillator for Low Standby Power Drain
• RC and Crystal Oscillator Outputs Are Capable of Driving External Loads
• Test Mode to Reduce Test Time
• V
• 'and V
• 'Pins Brought Out on Crystal Oscillator Inverter to Allow the Connection of External Resistors for Low-Power Operation
• Supply Voltage Range = 3.0 Vdc to 18 Vdc
• Capable of Driving Two Low-power TTL Loads or One Low-power Schottky TTL Load over the Rated Temperature Range.
• Pb-Free Packages are Available