Texas Instruments SN74LVC652ADBR

Overview

SN74LVC652ADBR 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, features dual clocking (CLKAB/CLKBA), dual select (SAB/SBA), and dual output-enable (OEAB/OEBA) controls, and delivers 7.4 ns max propagation delay at 3.3 V - used in FPGA-to-ASIC interconnect, memory-mapped I/O buffering, and industrial controller backplane interfaces.

For engineers reviewing the SN74LVC652ADBR datasheet, SN74LVC652ADBR pinout, SN74LVC652ADBR application, or SN74LVC652ADBR equivalent, key selection criteria include real-time vs. registered transfer modes, Ioff-enabled partial-power-down capability, 3.3-V/5-V mixed-signal compatibility, and TSSOP-24 package constraints for high-density PCB layouts.

Technical Context

The SN74LVC652ADBR integrates eight D-type flip-flops per bus direction, enabling synchronous storage of A- or B-bus data on low-to-high clock transitions. Its select-control logic eliminates multiplexer glitches during mode switching between real-time and stored data paths.

It implements independent OEAB/OEBA enables for A→B and B→A transceiver paths, and supports simultaneous storage in both registers when SAB = SBA = H and clocks are staggered - a capability confirmed in the function table for "Stored A data to B bus and stored B data to A bus" operation.

Key Specifications

Pinout & Package

SN74LVC652ADBR is housed in a 24-pin TSSOP (Thin Shrink Small Outline Package) with 0.65-mm lead pitch, 4.4-mm body width, and 1.2-mm maximum height - optimized for space-constrained industrial and communications PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC652APWR, SN74LVC652ADBR offers identical performance in a smaller TSSOP variant optimized for density, while SN74LVC652ADW trades size and thermal efficiency for broader manufacturability - making SN74LVC652ADBR the preferred choice for new designs targeting compact, high-speed industrial interfaces.

Availability

SN74LVC652ADBR is available at Aetrix Electronics and suitable for industrial PLC backplanes, FPGA-to-ASIC bridges, memory-mapped I/O buffering, and hot-swappable module interfaces requiring stable component supply across extended temperature ranges (–40°C to 85°C).

Supply support for SN74LVC652ADBR 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 innovation in high-reliability interface and power management ICs.

The SN74LVC652A product line targets high-speed, low-voltage bidirectional bus management in mixed-signal industrial and communications systems - emphasizing voltage translation, glitch-free control, and robust power-down behavior.

FAQ

What is the recommended power-up sequence for SN74LVC652ADBR to ensure high-impedance outputs?

To guarantee high-impedance state during power-up, OEBA must be tied to VCC through a pullup resistor and OEAB to GND through a pulldown resistor. The SN74LVC652ADBR datasheet specifies minimum resistor values based on driver strength; typical values are 10 kΩ for OEBA and 4.7 kΩ for OEAB. This prevents bus contention before firmware initializes control signals, and applies specifically to the SN74LVC652ADBR's TSSOP-24 implementation.

Does SN74LVC652ADBR support true bidirectional data flow without external direction control logic?

Yes - SN74LVC652ADBR enables independent A↔B data flow using OEAB (A→B enable) and OEBA (B→A enable). Unlike basic transceivers, it does not require a single DIR pin; instead, each direction is controlled separately, allowing simultaneous or asymmetric activation. This architecture is intrinsic to the SN74LVC652ADBR design and validated in its function table rows 7–10.

Can SN74LVC652ADBR operate reliably at 1.65 V while driving 5-V-tolerant inputs?

Yes - SN74LVC652ADBR is fully specified from 1.65 V to 3.6 V and guarantees 5.5-V input tolerance across this entire VCC range. At 1.65 V, VIH is 0.65 × VCC (1.07 V) and VIL is 0.35 × VCC (0.58 V), ensuring noise margins with 5-V CMOS outputs. This behavior is explicitly confirmed for the SN74LVC652ADBR in TI's SCAS303L datasheet Section 6.

What is the maximum clock frequency supported by SN74LVC652ADBR for registered data transfers?

The SN74LVC652ADBR supports up to 100 MHz clock frequency for registered transfers at VCC = 3.3 V ±0.3 V, as specified in the Timing Requirements table. At 1.8 V, maximum frequency is not published, but functional operation is guaranteed per recommended conditions. This 100-MHz capability applies directly to the SN74LVC652ADBR in TSSOP-24 and is measured with CL = 50 pF load.

How does the Ioff feature of SN74LVC652ADBR protect downstream circuitry during partial power-down?

The Ioff circuitry in SN74LVC652ADBR actively disables all outputs when VCC = 0 V, blocking reverse current flow from live buses (e.g., 5-V A-bus) into the unpowered device. This prevents latch-up and damage to upstream drivers - a requirement verified in TI's ESD and Ioff characterization tests for the SN74LVC652ADBR family. The feature functions identically across all package variants including SN74LVC652ADBR.