Octal transparent latch with tri-state bus control
The CD74HC373E is an octal D-type transparent latch from the 74HC series, configured as 8:8 with tri-state outputs. When the latch-enable (LE) input is high, the Q outputs follow the D inputs; when LE goes low, the last data state is latched. The output-enable (OE) pin places the eight outputs in a high-impedance state for bus-oriented systems. Supply voltage spans 2V to 6V, covering the full 74HC operating range. Propagation delay is 30ns typical — this sets the data-to-output settling time. For a bus operating at 10 MHz, the 30ns delay consumes 30% of the 100ns cycle, leaving 70ns for setup and hold at the receiver. The 7.8mA output high/low drive is sufficient for driving one or two standard TTL loads but not heavily loaded backplanes.
20-pin DIP package and board integration
Housed in a 20-DIP (0.300", 7.62mm) through-hole package with the supplier device package designated 20-PDIP. The 0.100-inch pin pitch and 0.300-inch row spacing are standard for breadboard prototyping and socketed designs. No special soldering profile beyond conventional wave or hand-solder — the DIP body tolerates 260°C peak for 10 seconds per JEDEC. The through-hole format simplifies rework and field replacement compared to surface-mount equivalents. A standard DIP socket or soldered through-hole connection provides mechanical retention under vibration without additional hardware.