Texas Instruments SN74LVC652ADWE4

Overview

SN74LVC652ADWE4 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 real-time or registered data transfer via dual clocks (CLKAB/CLKBA) and select controls (SAB/SBA), and delivers 7.4 ns max propagation delay at 3.3 V - used in industrial backplane interfaces and FPGA-to-ASIC interconnects.

For engineers reviewing the SN74LVC652ADWE4 datasheet, SN74LVC652ADWE4 pinout, SN74LVC652ADWE4 application, or SN74LVC652ADWE4 equivalent, key selection considerations include its dual-register architecture, Ioff partial-power-down support, 5.5-V-tolerant inputs, 3-state output enable sequencing, and compatibility with 1.8-V/2.5-V/3.3-V logic domains in high-density PCB layouts.

Technical Context

The SN74LVC652ADWE4 integrates eight independent bidirectional channels, each with D-type flip-flops on both A and B sides, enabling simultaneous storage of data from either bus or both buses. Its dual-clock design (CLKAB for A→B, CLKBA for B→A) and independent select controls (SAB/SBA) eliminate multiplexer glitches during mode transitions between real-time and stored data paths.

Control logic ensures deterministic behavior: low SAB/SBA selects real-time transfer; high enables registered output. OEAB/OEBA independently disable A→B or B→A outputs into high-impedance state, while Ioff circuitry blocks current backflow during power-down - critical for hot-swap and multi-rail system integrity.

Key Specifications

Pinout & Package

SN74LVC652ADWE4 is housed in a 24-pin TSSOP (PW) package, 7.9 mm × 4.5 mm × 1.2 mm, with 0.65-mm lead pitch and exposed thermal pad (non-electrical). Pin 1 index located at top-left corner; leads are gull-wing, RoHS-compliant NiPdAu finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC652ADWE4, SN74LVC652APWR provides identical functionality in optimized tape-and-reel form for high-volume assembly, while SN74LVC652ADWR offers SOIC packaging for thermal robustness and hand-soldering flexibility - all three share identical register architecture, Ioff behavior, and 5.5-V input tolerance.

Availability

SN74LVC652ADWE4 is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-ASIC bridges, hot-swappable module interconnects, and mixed-voltage sensor hubs requiring stable component supply across long-lifecycle programs.

Supply support for SN74LVC652ADWE4 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 SN74LVC652ADWE4 belongs to TI's LVC logic family - engineered for low-voltage, high-speed bidirectional bus management in space-constrained industrial and communications systems where voltage translation and register-controlled data flow are essential.

FAQ

What is the maximum clock frequency supported by SN74LVC652ADWE4?

The SN74LVC652ADWE4 supports a maximum clock frequency of 100 MHz at VCC = 3.3 V ±0.3 V, as specified in the timing characteristics table. At lower supply voltages (e.g., 1.8 V), maximum frequency is not characterized per the datasheet, but functional operation is guaranteed within the recommended operating conditions. The device achieves this performance with 7.4 ns typical propagation delay from clock to registered output.

Does SN74LVC652ADWE4 support 5-V input signals while operating at 1.8-V VCC?

Yes, SN74LVC652ADWE4 accepts input voltages up to 5.5 V regardless of VCC level (1.65 V to 3.6 V), enabling direct interfacing with 5-V TTL or CMOS outputs without external level-shifting circuitry. This is explicitly confirmed in the Recommended Operating Conditions table under "VI Input voltage" and reinforced by the "Support Mixed-Mode Signal Operation" feature statement.

How does the Ioff feature function in SN74LVC652ADWE4 during partial power-down?

The Ioff feature in SN74LVC652ADWE4 disables all outputs and isolates the A and B ports when VCC = 0 V, preventing current backflow from live buses into the unpowered device. This is achieved via internal circuitry that forces high-impedance states on all I/O pins - critical for hot-swap compliance and system-level power sequencing safety in modular electronics.

What is the correct power-up sequencing for OEAB and OEBA on SN74LVC652ADWE4?

To ensure high-impedance state during power-up, OEBA should be tied to VCC through a pullup resistor and OEAB to GND through a pulldown resistor. TI specifies minimum resistor values based on driver strength; typical values are 10 kΩ for pullup and 4.7 kΩ for pulldown. This prevents bus contention before firmware initializes the control lines - a requirement explicitly stated in the datasheet's application guidance section.

Can SN74LVC652ADWE4 simultaneously store data on both A and B buses?

Yes, SN74LVC652ADWE4 can store data on both buses simultaneously: a low-to-high transition on CLKAB stores A-port data into the A→B register, and a concurrent low-to-high transition on CLKBA stores B-port data into the B→A register. This is confirmed in the Function Table under "Store A and B data" (OEAB = L, OEBA = H, CLKAB↑, CLKBA↑), enabling synchronized dual-bus capture for time-aligned system monitoring.