Texas Instruments SN74HC623DWR

Overview

SN74HC623DWR from Texas Instruments is an octal bus transceiver IC designed for asynchronous two-way data communication between parallel buses. It features dual 3-state outputs (A↔B), wide 2 V to 6 V supply operation, ±6-mA output drive at 5 V, typical propagation delay of 8 ns, and low ICC of 80 µA max - enabling robust bidirectional bus isolation in industrial control backplanes and legacy system upgrades.

For engineers reviewing the SN74HC623DWR datasheet, SN74HC623DWR pinout, SN74HC623DWR application, or SN74HC623DWR equivalent, key selection considerations include its dual-enable (OEAB/OEBA) latch capability, true logic compatibility with HC-family timing, 20-pin SOIC-DW package footprint, and support for LSTTL load driving up to 15 units.

Technical Context

The SN74HC623DWR implements a dual-directional 8-bit transceiver architecture with independent output-enable controls (OEAB and OEBA) that determine data flow direction or enable bus-latch mode. Its CMOS design ensures rail-to-rail input thresholds (VIH = 3.15 V min at VCC = 4.5 V; VIL = 1.35 V max), and it operates across the full industrial temperature range (–40°C to +85°C).

When both OEAB and OEBA are asserted low, the device enters lock-bus-latch mode: each output reinforces its corresponding input, allowing stable retention of 16 bus-line states without external latching. This behavior is enabled only when all other drivers on both A and B buses are in high-impedance state.

Key Specifications

Pinout & Package

SN74HC623DWR is housed in a 20-pin SOIC (DW) package, 7.5 mm wide, 12.83 mm long, 2.65 mm max height, RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC623DWR, SN74HCT623DWR adds TTL input compatibility at no layout cost, while 74LCX623MTCX trades voltage range and pin compatibility for speed and 3.3 V optimization - making SN74HC623DWR the optimal choice for mixed-voltage, industrial-grade, drop-in bus isolation.

Availability

SN74HC623DWR is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy system bus extensions, real-time diagnostic snapshot circuits, configurable data path switching, and embedded controller bus bridging requiring stable component supply and long-term lifecycle support.

Supply support for SN74HC623DWR 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and logic solutions with over 50 years of industrial reliability heritage.

The SN74HC623DWR belongs to TI's 74HC logic family - engineered for robust, low-power, wide-supply-voltage digital interfacing in harsh environments including factory automation, instrumentation, and transportation systems.

FAQ

What is the maximum operating temperature range for SN74HC623DWR?

The SN74HC623DWR is rated for operation from –40°C to +85°C, meeting industrial temperature specifications. This range is validated per TI's recommended operating conditions and supported by thermal impedance data (θJA = 58°C/W for DW package). The device maintains specified timing and drive performance across this full range, making SN74HC623DWR suitable for deployment in uncontrolled ambient environments such as factory floors or outdoor enclosures.

Does SN74HC623DWR support bus-latch functionality, and how is it activated?

Yes, SN74HC623DWR supports lock bus-latch functionality. It is activated when both OEAB and OEBA inputs are driven low simultaneously. In this state, each output reinforces its corresponding input, allowing the A and B buses (16 total lines) to retain their last logic states - provided all other drivers on both buses are in high-impedance mode. This behavior is explicitly documented in the function table and logic diagram of the SN74HC623DWR datasheet.

Can SN74HC623DWR drive standard TTL loads directly?

Yes, SN74HC623DWR can drive up to 15 LSTTL loads directly, as confirmed by its ±6-mA output drive specification at VCC = 5 V and its stated compatibility with LSTTL fanout. This eliminates the need for external buffer stages when interfacing with legacy 74LS-series devices, making SN74HC623DWR ideal for upgrading aging TTL systems while preserving signal integrity and timing margins.

What is the propagation delay of SN74HC623DWR under typical conditions?

The typical propagation delay (tpd) of SN74HC623DWR is 8 ns at VCC = 5 V with CL = 50 pF, as measured from input transition to output transition (A↔B or B↔A). This value is guaranteed within the recommended operating conditions and reflects worst-case performance across process, voltage, and temperature corners - ensuring predictable timing in synchronous bus handshaking protocols used with SN74HC623DWR.

Is SN74HC623DWR pin-compatible with other packages in the same family?

Yes, SN74HC623DWR shares identical pinout and functionality with SN74HC623N (PDIP-20) and SN74HC623NSR (SOP-20), as confirmed by TI's ordering information table and top-view diagrams. All three variants use the same 20-pin configuration with matching signal assignments (OEAB, A1–A8, VCC, GND, B1–B8, OEBA), enabling direct PCB footprint interchangeability between SOIC, PDIP, and SOP packages without schematic or layout modification for SN74HC623DWR.