Texas Instruments SN74LVTH652PW

Overview

SN74LVTH652PW from Texas Instruments is a 3.3-V octal bus transceiver with dual D-type registers, supporting mixed-mode 5-V/3.3-V interfacing, real-time or stored data transfer, and hot-insertion via Ioff and power-up 3-state. It features bus-hold on all A/B data inputs, operates down to 2.7 V, and delivers 64 mA sink current per output at VCC = 3 V.

For engineers reviewing the SN74LVTH652PW datasheet, SN74LVTH652PW pinout, SN74LVTH652PW application, or SN74LVTH652PW equivalent, key selection criteria include bidirectional bus management with clocked storage, TTL-compatible 5-V input tolerance, bus-hold elimination of external resistors, and TSSOP-24 packaging for high-density PCB layouts.

Technical Context

The SN74LVTH652PW integrates two independent 8-bit bidirectional transceivers (A↔B), each with dedicated clock (CLKAB/CLKBA), select (SAB/SBA), and output-enable (OEAB/OEBA) controls. Its dual-register architecture allows simultaneous or staggered storage of A- and B-bus data without decoding glitches during mode transitions.

It implements active bus-hold circuitry on all 16 data terminals (A1–A8, B1–B8), eliminating floating-input risk, and uses Ioff to block reverse current during power-down. The device supports hot insertion by maintaining high-impedance outputs during VCC ramp (0–1.5 V) and enabling 3-state control above 1.5 V with proper OE biasing.

Key Specifications

Pinout & Package

TSSOP-24 package (PW), 7.8 mm × 4.4 mm × 1.2 mm max height, 0.65 mm lead pitch, exposed metal pad optional for thermal relief.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVTH652PW, SN74LVT652DW increases BOM count and layout complexity by requiring 16 external resistors, while SN74LVTH16652DL doubles data width but mandates new footprint, routing, and firmware register access logic - neither offers direct replacement capability.

Availability

SN74LVTH652PW is available at Aetrix Electronics and suitable for industrial backplane interfaces, legacy system bus bridges, modular test equipment, and communications protocol adapters requiring stable component supply across extended product lifecycles.

Supply support for SN74LVTH652PW 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 SN74LVTH652PW belongs to TI's LVT (Low-Voltage TTL) logic family, designed specifically for mixed-voltage system integration where 3.3-V logic must interoperate with legacy 5-V infrastructure.

FAQ

What is the primary function of the SN74LVTH652PW in a mixed-voltage system?

The SN74LVTH652PW serves as a bidirectional 3.3-V bus transceiver with dual 8-bit D-type registers, enabling seamless data exchange between 5-V TTL peripherals and 3.3-V logic domains. It accepts 5-V inputs while operating at 3.3-V VCC, supports real-time or stored data transfer, and provides bus-hold to eliminate external resistors - making it ideal for bridging legacy and modern subsystems without level shifters.

Does the SN74LVTH652PW support hot-plug operation, and how is it implemented?

Yes, the SN74LVTH652PW supports hot insertion through two complementary mechanisms: Ioff circuitry disables outputs when VCC = 0, preventing damaging back-current flow, and power-up 3-state forces outputs into high-impedance during VCC ramp (0–1.5 V). This ensures safe insertion/removal in live backplanes or modular chassis without disrupting adjacent powered components.

How does the bus-hold feature on the SN74LVTH652PW simplify PCB design?

The SN74LVTH652PW integrates active bus-hold circuitry on all 16 A/B data inputs (A1–A8, B1–B8), maintaining valid logic states on floating or unused lines without external pullup/pulldown resistors. This reduces BOM count by up to 16 passive components, saves board area, eliminates resistor placement errors, and improves noise immunity in high-density layouts - confirmed in TI's SCBS706F datasheet Section 2.

What are the timing constraints for reliable register loading on the SN74LVTH652PW?

For reliable register loading, the SN74LVTH652PW requires minimum clock pulse width (tw) ≥ 3.3 ns, setup time (tsu) ≥ 1.2 ns, and hold time (th) ≥ 0.8 ns at VCC = 2.7 V, per its timing specifications. Simultaneous clocking of both CLKAB and CLKBA is allowed only in real-time mode; for storing data into both registers, clocks must be staggered when SAB/SBA = H to avoid metastability - detailed in the FUNCTION TABLE and Figure 1 of the datasheet.

Can the SN74LVTH652PW operate below 3.3 V, and what performance trade-offs occur?

Yes, the SN74LVTH652PW is fully specified from 2.7 V to 3.6 V. At 2.7 V, output drive strength decreases (IOL drops to 48 mA, IOH to 24 mA), propagation delays increase slightly (tPLH/tPHL up to 5.9 ns), and bus-hold current reduces to ±75 µA. However, all logic thresholds, timing margins, and hot-insertion behavior remain guaranteed - enabling robust operation in brown-out or battery-depleted conditions.