Texas Instruments SN74LVC652APW

Overview

SN74LVC652APW 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 features Ioff partial-power-down protection. It is used in industrial control backplanes and FPGA-to-ASIC interface buffering.

For engineers reviewing the SN74LVC652APW datasheet, SN74LVC652APW pinout, SN74LVC652APW application, or SN74LVC652APW equivalent, key selection considerations include its 24-pin TSSOP package, dual-directional registered bus management, 3.3-V/5-V tolerant inputs, 7.4 ns max propagation delay at 3.3 V, and support for isolated or synchronized A↔B data routing with independent output enables.

Technical Context

The SN74LVC652APW 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 dual-clock architecture (CLKAB for A→B, CLKBA for B→A) and dual-select logic (SAB/SBA) eliminate multiplexer glitches during mode switching between real-time and stored data paths.

Control is implemented through four dedicated pins: OEAB/OEBA enable/disable transceiver outputs independently, while SAB/SBA determine whether outputs reflect live bus signals (low) or registered values (high). Inputs tolerate up to 5.5 V regardless of VCC, allowing direct interfacing with 5-V logic in 3.3-V systems without level shifters.

Key Specifications

Pinout & Package

TSSOP-24 (PW) package: 7.7 mm × 4.3 mm body, 0.65 mm lead pitch, 1.2 mm max height, gull-wing leads, RoHS-compliant NiPdAu finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC652ADW, the SN74LVC652APW offers 35% smaller PCB area and improved thermal performance in airflow-limited enclosures; compared with SN74LVC652APWR, it provides identical functionality with tube packaging suited for low-volume qualification, engineering samples, or repair stock.

Availability

SN74LVC652APW is available at Aetrix Electronics and suitable for industrial backplane interfaces, FPGA-to-ASIC bridging, and hot-swappable module interconnects requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for SN74LVC652APW 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 50 years of innovation in industrial, automotive, and communications markets.

The SN74LVC652APW belongs to TI's LVC logic family, engineered for low-voltage, high-speed, mixed-signal interface applications where voltage translation, bus registration, and power-aware operation are essential.

FAQ

What is the maximum clock frequency supported by the SN74LVC652APW?

The SN74LVC652APW 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 verified experimentally. The SN74LVC652APW achieves this performance with a typical propagation delay of 7.4 ns under those conditions.

Does the SN74LVC652APW require external pull-up or pull-down resistors on its enable pins?

Yes - to ensure defined high-impedance states during power-up or power-down, OEBA should be tied to VCC via a pull-up resistor and OEAB to GND via a pulldown resistor. The minimum resistor value depends on the driving source's current capability; TI recommends evaluating based on the specific driver's sink/source strength, as undefined enable states could cause bus contention before firmware initialization completes.

Can the SN74LVC652APW interface directly between a 5-V microcontroller and a 1.8-V FPGA?

No - while the SN74LVC652APW inputs tolerate up to 5.5 V regardless of VCC, its outputs swing only between GND and VCC. With VCC = 1.8 V, outputs cannot meet 5-V logic-high thresholds. For 5-V ↔ 1.8-V bidirectional translation, a dedicated level-shifting transceiver such as the TXB0108 is required; the SN74LVC652APW is suitable only for 3.3-V/5-V or 1.8-V/3.3-V mixed systems where the lower rail matches VCC.

Is the SN74LVC652APW pin-compatible with the SN74LVC652ADW?

Yes - the SN74LVC652APW (TSSOP-24) and SN74LVC652ADW (SOIC-24) share identical pin numbering, signal assignment, and functional behavior. Both use the same 24-pin layout with CLKAB, SAB, OEAB, A1–A8 on pins 1–11; GND on pin 12; VCC on pin 13; and CLKBA, SBA, OEBA, B1–B8 on pins 14–24. Mechanical mounting differs, but no schematic or firmware changes are needed when substituting between packages.

What is the purpose of the NC pins in the SN74LVC652APW package?

The SN74LVC652APW has no NC (no-connect) pins - all 24 pins are electrically assigned and functionally active. This differs from some other variants (e.g., SN54LVC652AFK in LCCC package) which include NC pins. In the TSSOP-24 PW package, every pin serves a defined role: 11 pins for A-side control/data, 11 for B-side control/data, plus VCC and GND. No pin should be left floating or tied arbitrarily.