NXP Semiconductors 74HCT373DB,112

Overview

74HCT373DB,112 from Nexperia is an octal D-type transparent latch with 3-state outputs, designed for bus-oriented digital systems requiring data latching and controlled output isolation. It features TTL-compatible input thresholds (VIH = 2.0 V min, VIL = 0.8 V max at VCC = 5 V), operates from 4.5 V to 5.5 V, supports -40 °C to +125 °C ambient range, and delivers 17 ns typical propagation delay (Dn→Qn) at VCC = 4.5 V. It is used in microcontroller address/data bus buffering and memory interface control.

For engineers reviewing the 74HCT373DB,112 datasheet, 74HCT373DB,112 pinout, 74HCT373DB,112 application, or 74HCT373DB,112 equivalent, this device serves as a critical bus-isolation latch where precise timing control, 3-state output enable coordination, and TTL-level compatibility with 5 V logic systems are required - especially in industrial control I/O expansion and legacy parallel bus architectures.

Technical Context

The 74HCT373DB,112 implements eight independent D-type latches with shared LE (latch enable, active HIGH) and OE (output enable, active LOW) controls. Its TTL-input compatibility ensures direct interfacing with 5 V microcontrollers and peripheral ICs without level-shifting.

Each latch operates in transparent mode when LE is HIGH (Qn follows Dn), and holds its state on the HIGH-to-LOW LE transition. OE independently places all Q0–Q7 outputs into high-impedance OFF-state without affecting internal latch states, enabling multi-device bus sharing.

Key Specifications

Pinout & Package

74HCT373DB,112 is packaged in SSOP20 (SOT339-1), a 20-pin shrink small outline package with 0.65 mm pitch, 7.2 mm body width, and exposed thermal pad (non-soldered). Pin 1 index located at top-left corner with notch marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal transparent latch applications.

Compared with 74HCT373PW,118, the 74HCT373DB,112 offers identical logic function and timing but in SSOP20 - providing better moisture resistance than TSSOP and easier hand-soldering than QFN, while maintaining full drop-in compatibility in 5 V bus systems.

Availability

74HCT373DB,112 is available at Aetrix Electronics and suitable for industrial control I/O expansion, microcontroller bus buffering, memory address latching, and legacy parallel interface applications requiring stable component supply across extended temperature ranges.

Supply support for 74HCT373DB,112 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Nexperia is a global semiconductor expert focused on essential efficiency technologies, delivering high-performance logic, analog, and MOSFET solutions for automotive, industrial, and consumer markets.

The 74HCT373DB,112 belongs to Nexperia's 74HCT logic family, engineered specifically for robust 5 V TTL-compatible interfacing in industrial and embedded systems where reliability, wide temperature operation, and bus integrity are critical.

FAQ

What is the maximum clock frequency supported by the 74HCT373DB,112?

The 74HCT373DB,112 does not operate on a clock signal - it is a transparent latch controlled by level-sensitive LE and OE inputs. Its usable data rate is determined by propagation delay (17 ns typ. D→Q) and setup/hold times (12 ns tsu, 4 ns th at VCC = 4.5 V), supporting reliable operation in bus cycles up to approximately 25 MHz with proper timing margins.

Can the 74HCT373DB,112 be used with 3.3 V logic systems?

No - the 74HCT373DB,112 is specified only for 4.5 V to 5.5 V supply and requires TTL-level inputs (VIH ≥ 2.0 V). At 3.3 V supply, VIH threshold is not met, resulting in unreliable HIGH recognition. For 3.3 V systems, use 74LVC373 or 74ALVC373 variants instead.

Is the SSOP20 package (SOT339-1) RoHS compliant and lead-free?

Yes - the 74HCT373DB,112 in SSOP20 packaging meets RoHS Directive 2011/65/EU and is manufactured with lead-free terminations (Pb-free, SnAgCu solderable finish), verified per Nexperia's material declarations and JEDEC J-STD-609 classification.

How does the 3-state output behavior interact with latch state during OE assertion?

Asserting OE (LOW) forces Q0–Q7 into high-impedance regardless of LE state or internal latch contents. The latches retain their stored data unchanged. When OE is deasserted (HIGH), outputs immediately reflect the current latch state - no re-latching or delay is introduced by OE toggling.