Texas Instruments SN74HC652DWR

Overview

SN74HC652DWR from Texas Instruments is an octal bus transceiver and register IC with 3-state outputs, designed for bidirectional data routing between two 8-bit buses (A and B) in synchronous digital systems. It supports real-time or stored-data transfer via independent select controls (SAB/SBA), features dual clock inputs (CLKAB/CLKBA) for A/B register latching, and operates across 2 V to 6 V with ±6-mA output drive at 5 V.

For engineers reviewing the SN74HC652DWR datasheet, SN74HC652DWR pinout, SN74HC652DWR application, or SN74HC652DWR equivalent, key selection criteria include its dual-register architecture, simultaneous real-time/stored-data multiplexing capability, 3-state bus isolation, 11-ns typical propagation delay at 5 V, and SOIC-24 package compatibility with industrial temperature range (–40°C to 85°C).

Technical Context

The SN74HC652DWR integrates eight independent D-type flip-flops per bus (A and B), enabling asynchronous storage of bus data on low-to-high clock transitions. Its control logic decouples register loading from output enable states-data can be latched regardless of OEAB/OEBA status, and real-time transfer occurs when SAB/SBA are low while 3-state outputs remain active.

It implements true bidirectional bus management: OEAB enables A→B transmission, OEBA enables B→A transmission, and both enables allow simultaneous bidirectional flow only when clocks and selects align for stored-data forwarding. The device guarantees high-impedance output control during power-up via recommended pullup/pulldown on OEBA/OEAB.

Key Specifications

Pinout & Package

SN74HC652DWR is housed in a 24-pin SOIC (DW) package with standard 0.300-inch body width and gull-wing leads. Pin numbering follows JEDEC MS-012, with Pin 1 located at top-left corner (Q1 quadrant) in tape-and-reel orientation.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC652DWR, SN74HCT652DW offers improved noise immunity in TTL-mixed systems without layout changes, while 74ACT652SCX delivers higher performance at the cost of supply rigidity and increased power - making SN74HC652DWR optimal for general-purpose industrial bus management where voltage range and low ICC are critical.

Availability

SN74HC652DWR is available at Aetrix Electronics and suitable for industrial PLC backplane interfaces, automotive ECU data multiplexing, and test equipment signal routing requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74HC652DWR 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 for industrial, automotive, and communications markets.

The SN74HC652DWR belongs to TI's 74HC high-speed CMOS logic family, engineered for reliable bidirectional bus management in noise-sensitive, multi-voltage embedded systems where low power and precise timing control are essential.

FAQ

What is the maximum clock frequency supported by SN74HC652DWR at 5 V?

The SN74HC652DWR supports a maximum clock frequency of 27 MHz at VCC = 5 V and TA = 25°C, as specified in the timing requirements table. This value assumes CL = 50 pF and accounts for worst-case setup/hold margins. At full industrial temperature range (–40°C to 85°C), derating applies - design margin should include 20% headroom for reliable operation in production systems using SN74HC652DWR.

Can SN74HC652DWR operate with a 3.3-V supply while interfacing with 5-V logic?

Yes, SN74HC652DWR operates over 2 V to 6 V, so it functions correctly at 3.3 V. However, its outputs swing rail-to-rail (0 V to 3.3 V), which may not meet VIH requirements of 5-V TTL inputs (typically ≥2 V). For reliable 3.3-V-to-5-V interfacing, external level-shifting circuitry or a TTL-compatible variant like SN74HCT652DW is recommended alongside SN74HC652DWR.

How does SN74HC652DWR handle bus contention during power-up?

SN74HC652DWR does not guarantee 3-state on power-up. To prevent bus contention, OEBA must be tied to VCC via a pullup resistor and OEAB to GND via a pulldown resistor - minimum values depend on driver sink/source capability. This ensures outputs remain high-impedance until firmware initializes control lines, a critical requirement for safe integration of SN74HC652DWR in hot-swap or fail-safe systems.

Is SN74HC652DWR pin-compatible with SN74HC640 or SN74HC646?

No, SN74HC652DWR is not pin-compatible with SN74HC640 or SN74HC646. SN74HC640 is an octal buffer with 3-state outputs only (no registers), and SN74HC646 combines transceiver and latch functions but uses different pin assignments for clocks and enables. SN74HC652DWR has dedicated CLKAB/CLKBA and SAB/SBA pins absent in those parts - direct replacement requires PCB redesign.

What is the thermal resistance (θJA) of the SN74HC652DWR SOIC package?

The SN74HC652DWR in SOIC (DW) package has a junction-to-ambient thermal resistance (θJA) of 46°C/W, measured per JESD 51-7. This value assumes standard JEDEC 2-layer board conditions. For sustained operation near maximum ICC (80 µA) and ambient temperatures approaching 85°C, no heatsinking is required - however, system-level thermal validation is advised when SN74HC652DWR operates in enclosed enclosures with limited airflow.