Texas Instruments SN74LVCH16652ADLG4

Overview

SN74LVCH16652ADLG4 from Texas Instruments is a 16-bit bus transceiver and register with 3-state outputs, designed for bidirectional data flow between A- and B-bus domains. It operates from 1.65 V to 3.6 V, supports 5.5-V-tolerant inputs, delivers ≤6.3 ns propagation delay at 3.3 V, and integrates D-type flip-flops with dual-clock (CLKAB/CLKBA) and dual-select (SAB/SBA) control-enabling real-time or registered data transfer in server backplanes and mixed-voltage I/O interfaces.

For engineers reviewing the SN74LVCH16652ADLG4 datasheet, SN74LVCH16652ADLG4 pinout, SN74LVCH16652ADLG4 application, or SN74LVCH16652ADLG4 equivalent, key selection criteria include its dual 8-bit channel architecture, bus-hold input retention, Ioff partial-power-down support, and compatibility with 3.3-V/5-V system-level voltage translation without external biasing.

Technical Context

The SN74LVCH16652ADLG4 implements two independent 8-bit transceiver channels (1A/1B and 2A/2B), each with dedicated clock (CLKAB/CLKBA), select (SAB/SBA), and output-enable (OEAB/OEBA) controls. Its internal D flip-flops allow synchronous latching of A- or B-bus data on low-to-high clock transitions, regardless of OE or S state.

Bus-hold circuitry actively maintains valid logic levels on all 32 I/O pins (A1–A16, B1–B16) without external resistors, while Ioff isolates inputs/outputs when VCC = 0 V. Input tolerance up to 5.5 V enables direct interfacing with legacy 5-V logic in 3.3-V systems.

Key Specifications

Pinout & Package

SN74LVCH16652ADLG4 is packaged in a 56-pin SSOP (DL package) with nominal body size 18.40 mm × 7.50 mm. Pin numbering follows standard top-view orientation with pin 1 at top-left corner.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74LVC16652DGGR and 74ALVCH16652TTR, the SN74LVCH16652ADLG4 uniquely combines 5.5-V input tolerance, bus-hold, Ioff, and 24-mA drive in a single 56-pin SSOP package-making it the only option qualified for robust mixed-voltage industrial and telecom infrastructure designs.

Availability

SN74LVCH16652ADLG4 is available at Aetrix Electronics and suitable for server backplanes, PC chipset expansion, and network switch ASIC interfaces requiring stable component supply, long-term lifecycle assurance, and guaranteed traceable sourcing.

Supply support for SN74LVCH16652ADLG4 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 decades of expertise in high-reliability interface ICs for computing and communications infrastructure.

The SN74LVCH16652ADLG4 belongs to TI's Widebus™ family of advanced bus-interface devices, engineered specifically for high-speed, mixed-voltage, register-controlled data routing in servers, networking equipment, and industrial control systems.

FAQ

What is the maximum clock frequency supported by SN74LVCH16652ADLG4?

The SN74LVCH16652ADLG4 supports up to 150 MHz clock frequency across its full operating temperature range (–40°C to 125°C) and VCC range (1.65 V to 3.6 V), as verified in timing specifications for both 40°C–85°C and 40°C–125°C conditions. This enables reliable use in high-throughput data path applications such as server memory buffers and switch fabric interfaces where deterministic register timing is critical. The SN74LVCH16652ADLG4 achieves this performance while maintaining ≤6.3 ns propagation delay at 3.3 V.

Does SN74LVCH16652ADLG4 support true 5-V to 3.3-V level translation?

Yes, SN74LVCH16652ADLG4 supports true 5-V to 3.3-V level translation: its inputs tolerate voltages up to 5.5 V regardless of VCC (1.65–3.6 V), allowing direct connection to 5-V logic outputs while operating from a 3.3-V supply. Outputs swing rail-to-rail within the VCC domain, so 3.3-V outputs interface safely with 5-V inputs that accept TTL-compatible thresholds. This eliminates external level shifters in mixed-voltage systems-confirmed by TI's "Mixed-Mode Signal Operation" feature description and absolute maximum ratings.

How does the bus-hold feature work on SN74LVCH16652ADLG4, and can it be disabled?

The bus-hold circuitry on SN74LVCH16652ADLG4 is integrated into each data input (A1–A16, B1–B16) and actively maintains the last-valid logic state when inputs float-eliminating need for external pull-up/down resistors. It draws ±45 μA to ±75 μA depending on VCC and input voltage, and cannot be disabled via any control pin (OE, CLK, or S). TI explicitly states bus-hold is "part of the input circuit and is not disabled by OE or DIR," making it always active and complementary to the device's robustness in unterminated or hot-swap scenarios.

What is the purpose of the Ioff feature in SN74LVCH16652ADLG4?

The Ioff feature in SN74LVCH16652ADLG4 disables the output drivers and isolates both inputs and outputs when VCC = 0 V, limiting leakage current to ±10 μA. This prevents current backflow from live buses into a powered-down section of the system-critical for hot-swap, partial-power-down, or power-gating architectures. Unlike standard CMOS, Ioff ensures signal integrity and safety during power sequencing mismatches, as confirmed in Electrical Characteristics (Ioff test condition: VI or VO = 5.5 V, VCC = 0 V).

Can SN74LVCH16652ADLG4 operate as two independent 8-bit transceivers?

Yes, SN74LVCH16652ADLG4 is explicitly structured as two independent 8-bit transceiver/register blocks: Channel 1 (pins 1A1–1A8, 1B1–1B8, 1CLKAB, 1CLKBA, 1SAB, 1SBA, 1OEAB, 1OEBA) and Channel 2 (pins 2A1–2A8, 2B1–2B8, 2CLKAB, 2CLKBA, 2SAB, 2SBA, 2OEAB, 2OEBA). Each has dedicated control signals, enabling simultaneous but asynchronous operation-for example, latching data on Channel 1 while passing real-time data on Channel 2. This dual-channel independence is documented in the Functional Block Diagram and Feature Description sections of the datasheet.