Texas Instruments SN74ALVCH16973DLR

Overview

SN74ALVCH16973DLR from Texas Instruments is an 8-bit bus transceiver with transparent D-type latch and four independent noninverting buffers, operating from 1.65 V to 3.6 V. It supports bidirectional A↔B data flow under DIR control, latches address signals on Q outputs via LE, and isolates buses using TOE/LOE. It is used in demultiplexed address/data bus architectures for microprocessor or FPGA-based embedded systems.

For engineers reviewing the SN74ALVCH16973DLR datasheet, SN74ALVCH16973DLR pinout, SN74ALVCH16973DLR application, or SN74ALVCH16973DLR equivalent, key selection factors include its 48-pin TSSOP (DGG) package, bus-hold inputs eliminating external resistors, ±24 mA drive strength at 3 V, sub-5 ns propagation delay, and simultaneous latch + transceiver + buffer functionality in one device.

Technical Context

The SN74ALVCH16973DLR integrates three functional blocks: an 8-bit bidirectional transceiver (A/B I/Os controlled by DIR and TOE), a transparent D-type latch (A→Q path enabled by LE, output state controlled by LOE), and four independent D→Y buffers unaffected by control signals. All I/Os feature bus-hold circuitry that maintains valid logic states without pullup/pulldown resistors.

Its timing architecture supports asynchronous operation: LE controls latch transparency (tsu/th = 0.9 ns), TOE enables/disables transceiver drivers (ten/tdis ≤ 4.9 ns), and LOE places Q outputs in high-Z (ten ≤ 4.9 ns). Input transition rate is specified at 10 ns/V, and all control inputs must be actively driven to VCC or GND.

Key Specifications

Pinout & Package

The SN74ALVCH16973DLR is packaged in a 48-pin TSSOP (DGG) with 0.5 mm pitch, 12.6 mm × 6.2 mm body, and 1.2 mm max height - optimized for high-density PCB layouts and automated SMT assembly.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus interface and latching applications.

Compared with SN74LVC16245ADGGR and SN74ALVCH162244DLR, the SN74ALVCH16973DLR uniquely combines latch, transceiver, and buffer in one device - enabling compact, low-latency bus architectures where timing-critical address/data separation is required without added propagation delay from cascaded ICs.

Availability

SN74ALVCH16973DLR is available at Aetrix Electronics and suitable for industrial PLC backplanes, automotive ECU memory subsystems, and FPGA I/O expansion hubs requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for SN74ALVCH16973DLR 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 90 years of innovation in industrial, automotive, and communications markets.

The SN74ALVCH16973DLR belongs to TI's Widebus™ family of advanced logic devices, designed specifically for high-speed, low-voltage bus interface applications in space-constrained and thermally demanding embedded systems.

FAQ

What is the primary function of the SN74ALVCH16973DLR in a microprocessor system?

The SN74ALVCH16973DLR serves as a combined 8-bit bus transceiver, transparent D-type latch, and quad buffer. In microprocessor systems, it demultiplexes a time-multiplexed address/data bus: latching address bits onto Q outputs (controlled by LE), routing data bidirectionally between A and B buses (controlled by DIR and TOE), and buffering control signals independently (D→Y). This integration replaces multiple discrete logic devices, reducing latency and PCB footprint.

Does the SN74ALVCH16973DLR require external pullup or pulldown resistors on its data inputs?

No, the SN74ALVCH16973DLR does not require external pullup or pulldown resistors on its A, B, or D inputs because all I/Os and D inputs feature integrated bus-hold circuitry. This circuitry actively maintains the last-valid logic state on undriven or floating inputs, with sustaining currents up to ±75 µA at 3 V. Using external resistors with bus-hold is explicitly discouraged in the datasheet as it may cause contention or increased power draw.

How does the latch-enable (LE) and latch-output-enable (LOE) interact in the SN74ALVCH16973DLR?

In the SN74ALVCH16973DLR, LE controls data capture: when LE is high, Q outputs follow A inputs (transparent mode); when LE goes low, Q holds the A values present at that instant. LOE operates independently - when LOE is low, Q outputs drive logic-high or logic-low; when LOE is high, Q outputs enter high-impedance (tri-state), regardless of LE state or stored data. This allows retained latch data to remain internally valid while externally isolated - critical for bus sharing and hot-swap designs.

What is the maximum propagation delay for data transfer from A to B in the SN74ALVCH16973DLR at 3.3 V?

At VCC = 3.3 V, the maximum propagation delay (tpd) for data transfer from A to B in the SN74ALVCH16973DLR is 3.2 ns, as specified in the Switching Characteristics table under "A → B" with VCC = 3.3 V ± 0.3 V. This value represents worst-case delay across temperature (–40°C to +85°C) and process variation, ensuring timing margin for high-speed bus protocols such as 8080-style parallel interfaces running up to 100 MHz.

Can the SN74ALVCH16973DLR operate reliably at 1.8 V supply voltage?

Yes, the SN74ALVCH16973DLR is fully specified to operate at 1.8 V (within its 1.65 V to 3.6 V VCC range). At 1.8 V, it delivers ≥4 mA output drive (IOL), supports input thresholds scaled to 0.65×VCC (VIH) and 0.35×VCC (VIL), and maintains bus-hold functionality. Propagation delay increases to 3.3 ns (A→B), and power dissipation drops significantly - making it suitable for low-power portable and battery-operated industrial sensors interfaced to 1.8 V FPGAs or MCUs.