CD4028

The CD4028 is a complementary metal-oxide-semiconductor (CMOS) integrated circuit that functions as a decade counter/decoder. It is a 1-of-10 decoder, meaning it takes a 4-bit binary input and outputs one of ten possible active-high lines corresponding to the decimal value of the input. Each of the ten outputs (Q0 through Q9) is activated sequentially as the counter increments through its valid states. The device has a clock input (C) which is edge-triggered, typically on the rising edge. It also features an enable input (E) and a reset input (R). When the enable input is low, the counter is disabled and holds its current state. When the reset input is high, all outputs are reset to a low state, and the counter starts from zero upon removal of the reset signal. The CD4028 is commonly used in digital systems for tasks such as selecting one of ten options based on a binary code, driving decimal displays like Nixie tubes or seven-segment displays, and as a basic building block for more complex counting and decoding circuits. Its CMOS technology offers low power consumption and a wide operating voltage range.