MM74HC259MX

The MM74HC259MX from On Semiconductor is an advanced silicon-gate CMOS 8-bit addressable latch, suitable for general-purpose storage in digital systems. This device features a single data input (D), 8 latch outputs (Q1–Q8), 3 address inputs (A, B, C), a common enable input (G), and a common CLEAR input.

To operate as an addressable latch, data is applied to the D input, and the desired latch is selected using the A, B, and C address inputs. When the ENABLE input is LOW, data flows to the addressed output. Data is stored when ENABLE transitions from LOW to HIGH. All unaddressed latches remain unaffected. With ENABLE HIGH, the device is deselected, and latches retain their previous state.

If ENABLE is held HIGH and CLEAR is taken LOW, all eight latches are cleared to a LOW state. If ENABLE is LOW, all latches except the addressed one are cleared, while the addressed latch follows the D input, effectively functioning as a 3-to-8 line decoder. All inputs are protected against static discharge.

The MM74HC259MX is available in a 16-SOIC package, designed for surface mounting. It operates over a temperature range of -40°C to 85°C and supports a wide supply voltage range of 2V to 6V, with a typical propagation delay of 17ns. Its low input current (1μA max) and quiescent current (80μA max) make it suitable for various digital applications.