Diodes Incorporated PI74FCT373TQE

Overview

PI74FCT373TQE from Pericom Semiconductor is an 8-bit octal transparent latch with 3-state outputs, designed for bus-oriented digital systems where data isolation and controlled latching are required. It features TTL-compatible input/output levels, 5V supply operation, industrial temperature range (–40°C to +85°C), propagation delay as low as 3.8 ns (FCT-D grade), and low static power consumption (0.1 µA typical ICC). It is used in microprocessor data bus buffering and address/data latching in embedded control modules.

For engineers reviewing the PI74FCT373TQE datasheet, PI74FCT373TQE pinout, PI74FCT373TQE application, or PI74FCT373TQE equivalent, key selection considerations include latch enable polarity (active-HIGH), output enable polarity (active-LOW), 3-state bus drive capability, ground bounce suppression, and compatibility with FAST™-series logic footprints in space-constrained TSSOP/QSOP layouts.

Technical Context

The PI74FCT373TQE implements a parallel 8-bit transparent latch architecture: when LE is HIGH, inputs D0–D7 pass directly to outputs O0–O7; when LE transitions LOW, the input state at that instant is captured and held. OE controls output driver enablement - HIGH forces all outputs into high-impedance (Z) state, enabling shared bus operation.

It uses Fast CMOS process technology with hysteresis on all inputs (200 mV), TTL-level compatible thresholds (VIH = 2.0 V, VIL = 0.8 V), and rail-to-rail output swing (VOH ≥ 2.4 V at –15 mA, VOL ≤ 0.55 V at 64 mA). Its quiescent current is 0.1 µA typical, and dynamic supply current scales linearly with input toggle rate and number of active inputs.

Key Specifications

Pinout & Package

PI74FCT373TQE is packaged in a 20-pin QSOP (Q) with 0.65 mm pitch, 7.6 mm × 4.4 mm body, and gull-wing leads. This compact surface-mount package supports automated assembly and thermal performance suitable for dense PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74F373SCX, PI74FCT373TQE delivers 4× lower static power and 4× faster propagation, while versus SN74ACT373N it adds industrial temperature qualification and superior bus drive strength - making it optimal for ruggedized embedded control.

Availability

PI74FCT373TQE is available at Aetrix Electronics and suitable for industrial PLCs, test instrumentation, legacy system upgrades, and microcontroller-based data acquisition requiring stable component supply across multi-year production cycles.

Supply support for PI74FCT373TQE 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

Pericom Semiconductor was a fabless provider specializing in high-speed interface, timing, and logic ICs before its acquisition by Diodes Incorporated in 2016; its FCT-family logic remains widely deployed in industrial and communications infrastructure.

The PI74FCT373TQE belongs to Pericom's Fast CMOS (FCT) logic product line, engineered specifically for 5V bus-interface applications demanding low power, high noise immunity, and pin compatibility with legacy bipolar logic families.

FAQ

What is the function of the LE and OE pins on the PI74FCT373TQE?

LE (Latch Enable) is an active-HIGH control: when HIGH, the device operates transparently (D0–D7 appear at O0–O7); on the falling edge of LE, the current input state is latched and held. OE (Output Enable) is active-LOW: when HIGH, all outputs enter high-impedance state, disconnecting the latch from the bus. Both controls operate independently and concurrently.

Can PI74FCT373TQE operate at 3.3 V?

No. The PI74FCT373TQE is specified exclusively for 5.0 V ±5% operation (4.75 V to 5.25 V). Its input thresholds (VIH = 2.0 V, VIL = 0.8 V) and output drive characteristics are optimized for 5V TTL/CMOS interfacing. Applying 3.3 V to VCC will result in undefined logic states, insufficient output swing, and potential damage due to internal biasing constraints.

How does the PI74FCT373TQE differ from the PI74FCT573TQE?

The PI74FCT373TQE has separate input (D0–D7) and output (O0–O7) pins arranged for non-inverting transparent latching, whereas the PI74FCT573TQE uses bidirectional I/O pins (D0–D7 serve as both inputs and outputs). Pinouts differ: PI74FCT373TQE places outputs adjacent to inputs per bit (e.g., D0–O0–D1–O1), while PI74FCT573TQE groups all Dn together and all On together - requiring PCB layout changes for substitution.

Is there a lead-free and RoHS-compliant version of PI74FCT373TQE?

Yes. The "QE" suffix denotes a lead-free, RoHS-compliant variant with matte tin (Sn) lead finish and halogen-free molding compound. It meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL-3) and is qualified for reflow soldering per IPC/JEDEC J-STD-020D. No special handling beyond standard MSL-3 precautions is required.