Diodes Incorporated PI74FCT245CTQE

Overview

PI74FCT245CTQE from Pericom Semiconductor is an octal bidirectional transceiver IC designed for asynchronous two-way data bus interfacing between TTL/CMOS systems. It features 8-bit A/B port pairs, active-low 3-state output enable (OE), transmit/receive direction control (T/R), 5V supply operation, and 4.1 ns max propagation delay (A→B/B→A) at 50 pF load. Used in industrial backplane and motherboard bus isolation.

For engineers reviewing the PI74FCT245CTQE datasheet, PI74FCT245CTQE pinout, PI74FCT245CTQE application, or PI74FCT245CTQE equivalent, key selection criteria include bidirectional timing symmetry, 25°C–85°C industrial temperature range, 2.4 V VOH at –15 mA, 0.55 V VOL at 64 mA, and TSSOP-20 package compatibility with high-density PCB layouts.

Technical Context

This device implements dual 8-bit bidirectional I/O ports with independent direction control via T/R and tristate control via OE. All inputs exhibit 200 mV hysteresis for noise immunity, and outputs drive 50 Ω transmission lines without external termination in the FCT2245 variant-though PI74FCT245CTQE lacks built-in 25 Ω series resistors.

It operates strictly at 5.0 V ±5% supply, supports TTL-level input thresholds (VIH = 2.0 V, VIL = 0.8 V), and delivers rail-to-rail CMOS-compatible outputs with low ground bounce and quiescent current as low as 0.1 µA. The architecture enables hot-swap-safe bus isolation when OE is asserted.

Key Specifications

Pinout & Package

PI74FCT245CTQE is housed in a 20-pin TSSOP (Thin Shrink Small Outline Package), 173-mil wide body, 0.65 mm pitch, with exposed thermal pad not electrically connected. Pin 1 marked by beveled corner or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal bidirectional transceiver applications.

Compared with SN74F245N and 74LCX245MTCX, PI74FCT245CTQE uniquely balances 5 V native operation, sub-5 ns latency, <500 µA quiescent current, and industrial temperature qualification - making it optimal for cost-sensitive, thermally demanding 5 V bus isolation where legacy pinout retention matters.

Availability

PI74FCT245CTQE is available at Aetrix Electronics and suitable for industrial backplane interfaces, embedded controller bus isolation, and telecom line card data multiplexing requiring stable component supply across extended lifecycle programs.

Supply support for PI74FCT245CTQE 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 signal-integrity solutions before its acquisition by Diodes Incorporated in 2016.

This device belongs to the PI74FCT logic family, engineered for 5 V TTL/CMOS bus bridging with emphasis on low power, noise immunity, and industrial reliability - targeting industrial control, telecom infrastructure, and test equipment.

FAQ

Is PI74FCT245CTQE 5 V tolerant on all I/O pins?

Yes - all A0–A7 and B0–B7 pins are fully 5 V tolerant with guaranteed VIH = 2.0 V and VIL = 0.8 V under 5.0 V ±5% VCC. Input clamp diodes limit VIN to –0.7 V minimum and 5.7 V maximum, protecting against transient overvoltage.

Does PI74FCT245CTQE include built-in 25 Ω series resistors?

No - only the PI74FCT2245CTQE variant includes 25 Ω series resistors on all outputs. The PI74FCT245CTQE requires external 25–50 Ω source termination for optimal transmission line matching in high-speed applications.

What is the maximum clock/data toggle rate supported?

While not a clocked device, it supports sustained bidirectional data toggling up to 100 MHz under loaded conditions (50 pF), based on 4.1 ns max propagation delay and 5.0 ns max output enable/disable times - verified across –40°C to +85°C.

Can OE and T/R be tied together for unidirectional operation?

Yes - tying OE and T/R simplifies control logic for fixed-direction use (e.g., A→B only), but disables dynamic direction reversal. In that configuration, OE = LOW enables A→B flow; OE = HIGH forces both sides into Hi-Z regardless of T/R state.