Texas Instruments SN74ALVCH16973DGGR

Overview

SN74ALVCH16973DGGR 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 enables. Used in demultiplexed address/data bus architectures for microprocessor co-processor interfaces.

For engineers reviewing the SN74ALVCH16973DGGR datasheet, SN74ALVCH16973DGGR pinout, SN74ALVCH16973DGGR application, or SN74ALVCH16973DGGR equivalent, key selection criteria include 48-pin TSSOP package compatibility, bus-hold input retention, ±24 mA drive strength at 3 V, and simultaneous latch + transceiver + buffer functionality in a single device.

Technical Context

This device integrates three logically distinct functional blocks: (1) an 8-bit noninverting transceiver (A↔B I/Os) controlled by DIR and TOE, (2) an 8-bit transparent D-latch (A→Q path) with LE and LOE enables, and (3) four independent noninverting buffers (D→Y). All I/Os feature active bus-hold circuitry eliminating external pull resistors.

Timing-critical operations include LE-controlled latching with 0.9 ns setup/hold times (at 1.8 V), sub-5 ns enable/disable delays (ten/tdis), and propagation delays as low as 0.5 ns (tpd at 3.3 V). The latch output-enable (LOE) operates independently of internal latch state, enabling high-impedance Q-bus retention during data updates.

Key Specifications

Pinout & Package

TSSOP-48 (DGG) package: 12.6 mm × 6.2 mm × 1.2 mm body, 0.5 mm pitch, 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 bus interface applications.

Compared with SN74ALVCH16973DGGR, SN74LVC16245ADGGR lacks integrated latching and bus-hold, increasing design complexity for demux applications, while SN74ALVCH162244DGGR omits bidirectional capability entirely - making SN74ALVCH16973DGGR the sole solution supporting concurrent latch + transceiver + buffer operation in one package.

Availability

SN74ALVCH16973DGGR is available at Aetrix Electronics and suitable for microprocessor demultiplexing, FPGA I/O expansion, industrial PLC backplane interfacing, and automotive ECU memory subsystems requiring stable component supply across extended temperature ranges.

Supply support for SN74ALVCH16973DGGR 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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, personal electronics, and communications markets.

The SN74ALVCH16973DGGR belongs to TI's Widebus™ family of advanced low-voltage CMOS logic devices, engineered specifically for high-speed, low-power, mixed-voltage bus interface applications in space-constrained embedded systems.

FAQ

What is the maximum clock frequency supported by SN74ALVCH16973DGGR for latch operation?

The SN74ALVCH16973DGGR does not operate on a clock signal - it is a level-sensitive transparent latch. Its timing is governed by setup/hold requirements relative to the LE input: minimum 0.9 ns tsu/th at 1.8 V. Maximum effective latch rate depends on system-level timing margins but is typically limited to ≤110 MHz in practice due to propagation delay and enable timing constraints. The SN74ALVCH16973DGGR datasheet specifies no maximum clock frequency because it has no internal clock.

Can SN74ALVCH16973DGGR interface directly with 5-V logic systems?

SN74ALVCH16973DGGR is not 5-V tolerant: its absolute maximum input voltage is VCC + 0.5 V (≤4.1 V at 3.6 V VCC). Direct connection to 5-V logic risks damage. Safe interfacing requires external level-shifting circuitry (e.g., TI TXS0108E) or clamping diodes with current limiting. The SN74ALVCH16973DGGR is designed for 1.65–3.6 V domains only - mixing with 5 V violates absolute maximum ratings.

How does bus-hold functionality behave during power-up sequences?

During power-up, SN74ALVCH16973DGGR bus-hold circuitry activates once VCC reaches ~1.2 V and remains active across the full 1.65–3.6 V operating range. It holds floating A/B/D inputs at their last valid logic state, preventing metastability. However, TOE and LOE must be pulled to VCC via ≥10 kΩ resistors during power-up to guarantee high-impedance isolation - the SN74ALVCH16973DGGR itself does not auto-tri-state on power ramp.

What is the recommended PCB layout practice for minimizing noise on the Q outputs of SN74ALVCH16973DGGR?

To minimize noise on SN74ALVCH16973DGGR Q outputs, place 0.1 µF ceramic decoupling capacitors within 3 mm of each VCC/GND pair, use solid ground planes beneath the device, route Q traces away from noisy A/B bus lines, and avoid sharp bends or stubs. The SN74ALVCH16973DGGR's 3 pF output capacitance helps, but proper layout reduces crosstalk-induced jitter - especially critical for address hold timing in high-speed memory interfaces.

Does SN74ALVCH16973DGGR support hot-swap or live-insertion applications?

SN74ALVCH16973DGGR supports hot-swap applications when TOE and LOE are held high (via pullups) during insertion to maintain A/B/Q buses in high-impedance states. Its bus-hold inputs prevent floating nodes, and latch state is retained during VCC ramp. However, TI does not guarantee hot-swap compliance - system-level testing per IEC 61000-4-2 is required. The SN74ALVCH16973DGGR's 2000-V HBM ESD rating aids robustness but does not replace full hot-swap qualification.