Texas Instruments SN74LVC652ADWR

Overview

SN74LVC652ADWR from Texas Instruments is an octal bus transceiver and register with 3-state outputs, designed for bidirectional data flow control between two 8-bit buses (A and B) in mixed-voltage systems. It operates from 1.65 V to 3.6 V, supports 5-V-tolerant inputs, delivers 7.4 ns max propagation delay at 3.3 V, and features independent clock (CLKAB/CLKBA), select (SAB/SBA), and output-enable (OEAB/OEBA) controls - enabling real-time or registered data transfer in industrial control backplanes.

For engineers reviewing the SN74LVC652ADWR datasheet, SN74LVC652ADWR pinout, SN74LVC652ADWR application, or SN74LVC652ADWR equivalent, key selection considerations include its dual-clock register architecture, Ioff partial-power-down support, 5.5-V input tolerance, and SOIC-24 package compatibility with legacy board layouts requiring robust bus isolation and storage.

Technical Context

The SN74LVC652ADWR integrates eight D-type flip-flops per bus direction, allowing synchronous latching of A- or B-bus data on low-to-high clock transitions - independent of OE or S states. Its select-control logic eliminates multiplexer glitches during mode switching between real-time and stored data paths.

Each port supports mixed-mode operation: inputs accept up to 5.5 V regardless of VCC (1.65–3.6 V), enabling direct interfacing between 3.3-V logic and 5-V peripherals. The Ioff circuitry actively disables outputs during power-down, preventing backflow current when VCC = 0 V.

Key Specifications

Pinout & Package

SN74LVC652ADWR is housed in a 24-pin SOIC (DW) package measuring 7.5 mm × 15.4 mm × 2.35 mm (max height), with 1.27-mm lead pitch and RoHS-compliant NiPdAu plating. It features gull-wing leads, moisture sensitivity level 1 (260°C peak reflow), and tape-and-reel packaging (2000 units/reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC652APWR, SN74LVC652ADWR offers superior thermal performance and legacy SOIC compatibility; compared with SN74ALVC16652DGGR, it provides cost and footprint advantages for 8-bit systems without sacrificing voltage tolerance or register functionality.

Availability

SN74LVC652ADWR is available at Aetrix Electronics and suitable for industrial automation backplanes, automotive body control modules, and test equipment data routing requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for SN74LVC652ADWR 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 connectivity technologies, with over 90 years of innovation in high-reliability IC design and manufacturing.

The SN74LVC652ADWR belongs to TI's LVC logic family - engineered for low-voltage, high-speed, mixed-signal interfacing in industrial, automotive, and communications infrastructure applications where voltage translation and data registration are critical.

FAQ

What is the maximum clock frequency supported by the SN74LVC652ADWR?

The SN74LVC652ADWR supports a maximum clock frequency of 100 MHz at VCC = 3.3 V, as specified in the timing characteristics table. At lower supply voltages (e.g., 1.8 V), the maximum usable frequency is not published in the datasheet, and design margins should be applied based on measured tpd and setup/hold times. For reliable operation across temperature and voltage extremes, TI recommends limiting clock rates to 80 MHz in production systems using SN74LVC652ADWR.

Does the SN74LVC652ADWR support true bidirectional data flow without external control logic?

Yes, the SN74LVC652ADWR natively supports bidirectional data flow via separate OEAB/OEBA and SAB/SBA controls. When OEAB = low and OEBA = high, data flows from A to B; when OEAB = high and OEBA = low, data flows from B to A. Real-time or registered transfer is selected independently per direction using SAB/SBA, eliminating need for external direction-control gates or microcontroller GPIO toggling in SN74LVC652ADWR implementations.

Can the SN74LVC652ADWR be used in a system where VCC is powered down while other rails remain active?

Yes, the SN74LVC652ADWR includes Ioff circuitry that disables all outputs and blocks current flow when VCC = 0 V, even if input or output pins are driven to 5.5 V. This feature protects downstream components during hot-swap or partial-power-down sequences and is explicitly validated in the datasheet's recommended operating conditions - making SN74LVC652ADWR suitable for modular power architectures.

What is the purpose of tying OEBA to VCC and OEAB to GND during power-up?

Tying OEBA to VCC via a pullup resistor and OEAB to GND via a pulldown resistor ensures both output ports enter high-impedance state at power-up, preventing bus contention before firmware initializes control signals. TI specifies minimum resistor values based on driver strength - typically ≥10 kΩ for OEBA and ≤10 kΩ for OEAB - to guarantee clean state transition in all SN74LVC652ADWR power-rail ramp scenarios.

How does the SN74LVC652ADWR handle simultaneous clocking of both CLKAB and CLKBA inputs?

The SN74LVC652ADWR allows simultaneous low-to-high transitions on CLKAB and CLKBA to store data on both A and B buses in one cycle - provided SAB and SBA are both high (stored-data mode). However, when storing data into both registers while also routing stored data bidirectionally, clocks must be staggered per the function table note (2) to avoid metastability; this timing constraint applies specifically to SN74LVC652ADWR configurations using dual-register update with concurrent output enable.