HEF4521B Description
The HEF4521B consists of a chain of 24 toggle flip-flops with an overriding asynchronous master reset input (MR), and an input circuit that allows three modes of operation. The single inverting stage (I2/O2) will function as a crystal oscillator, or in bination with I1 as an RC oscillator, or as an input buffer for an external oscillator. Low-power HEF4521B MSI operation as a crystal oscillator is enabled by...