Renesas IDT74FCT543DTQG8

Overview

IDT74FCT543DTQG8 from Renesas Electronics is a non-inverting octal latched transceiver in QSOP-24 package, operating at 5.0V ±5% over –40°C to +85°C, with 6.5ns max propagation delay (A-grade), ±1µA max input/output leakage, and 64mA IOL drive capability. It enables bidirectional data flow between two 8-bit buses in industrial control backplanes.

For engineers reviewing the IDT74FCT543DTQG8 datasheet, IDT74FCT543DTQG8 pinout, IDT74FCT543DTQG8 application, or IDT74FCT543DTQG8 equivalent, key selection criteria include latch-enable timing (5ns min LE pulse width), 3-state output disable time (7.5ns max), true TTL-compatible inputs (VIH = 2.0V min), and industrial-grade reliability for bus isolation in programmable logic interfaces.

Technical Context

The IDT74FCT543DTQG8 implements dual independent 8-bit latch paths with separate A-to-B and B-to-A control logic: CEAB/LEAB/OEAB govern A→B direction, while CEBA/LEBA/OEBA manage B→A flow. Each path supports transparent latch mode and storage mode with edge-triggered latch enable.

It uses advanced dual-metal CMOS technology to achieve TTL-level input thresholds (VIH = 2.0V, VIL = 0.8V) and rail-aligned outputs (VOH = 2.4V min at –8mA, VOL = 0.55V max at 64mA), meeting JEDEC Std 18 while delivering CMOS power efficiency (ICC ≤ 1mA).

Key Specifications

Pinout & Package

Package: 24-pin QSOP (PCG24), 3.9mm width, 0.635mm pitch, JEDEC MO-137 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with 74FCT543ATQG and SN74F543N, IDT74FCT543DTQG8 delivers optimal balance of industrial temperature resilience, QSOP-24 miniaturization, and 6.5ns timing precision - making it the preferred choice for new designs requiring automated assembly and robust bus isolation.

Availability

IDT74FCT543DTQG8 is available at Aetrix Electronics and suitable for industrial backplane interfaces, programmable logic bus isolation, and motor drive control hubs requiring stable component supply across extended product lifecycles.

Supply support for IDT74FCT543DTQG8 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

Renesas Electronics Corporation is a global semiconductor leader specializing in microcontrollers, analog, power, and timing solutions for industrial, automotive, and infrastructure markets.

IDT74FCT543DTQG8 belongs to the legacy IDT Fast CMOS logic family, designed specifically for high-reliability 5V bus interfacing in industrial control systems requiring latch-based data synchronization and hot-swap capability.

FAQ

What is the maximum clock frequency supported by IDT74FCT543DTQG8 for latch enable transitions?

IDT74FCT543DTQG8 does not operate on a clock signal - it is an asynchronous latch transceiver. Its LEAB/LEBA inputs respond to edge-triggered transitions, with minimum pulse width of 5ns. The device supports data rates up to 100MHz in transparent mode (based on 6.5ns propagation delay), but latching is controlled solely by the LE signal's LOW-to-HIGH edge, not periodic clocking. Timing margins must be verified per application using tSU = 2ns and tH = 2ns.

Does IDT74FCT543DTQG8 support mixed-voltage operation between 3.3V and 5V domains?

IDT74FCT543DTQG8 operates exclusively at 5.0V ±5% and is not mixed-voltage capable. Its inputs accept TTL-level thresholds (VIH = 2.0V min, VIL = 0.8V max), allowing direct connection to 3.3V CMOS outputs that meet those levels - but the device itself requires a 5V supply and generates 5V-compatible outputs. For true 3.3V ↔ 5V translation, a dedicated level-shifter IC is required upstream or downstream of IDT74FCT543DTQG8.

Can IDT74FCT543DTQG8 be used for unidirectional data transfer only?

Yes - IDT74FCT543DTQG8 supports unidirectional operation by holding one direction's enable inputs inactive. For A→B only: tie CEBA and OEBA HIGH (inactive), and control CEAB/LEAB/OEAB normally. For B→A only: tie CEAB and OEAB HIGH, and use CEBA/LEBA/OEBA. Unused I/O pins (e.g., B0–B7 in A→B mode) remain in high-impedance state when their associated OE is HIGH, eliminating contention risk.

What is the thermal resistance (θJA) of IDT74FCT543DTQG8 in its QSOP-24 package?

The datasheet for IDT74FCT543DTQG8 does not specify θJA (junction-to-ambient thermal resistance). As a low-power CMOS device with typical ICC ≤ 1mA and dynamic current ≤ 7.3mA under full toggle, its power dissipation remains below 40mW at 5V - well within the safe operating area of the QSOP-24 package without heatsinking. Thermal design margin is inherently sufficient for industrial ambient conditions up to +85°C.

Is IDT74FCT543DTQG8 RoHS compliant and lead-free?

Yes - IDT74FCT543DTQG8 is RoHS compliant and lead-free. The "G" suffix in the part number denotes green (halogen-free, lead-free) packaging, and the ordering information confirms compliance per Renesas' 2020 rebranding update. It meets EU RoHS Directive 2011/65/EU and is suitable for environmentally regulated industrial deployments.