Texas Instruments SN74LVCH16646ADL

Overview

SN74LVCH16646ADL from Texas Instruments is a 16-bit bus transceiver and register with 3-state outputs, designed for 1.65 V to 3.6 V V_CC operation. It supports mixed-mode signal operation (5-V inputs with 3.3-V V_CC), features bus-hold on all data inputs, and delivers 5.7 ns max propagation delay at 3.3 V. It enables real-time or registered bidirectional data transfer between two 8-bit buses in industrial control backplanes and memory-mapped I/O interfaces.

For engineers reviewing the SN74LVCH16646ADL datasheet, SN74LVCH16646ADL pinout, SN74LVCH16646ADL application, or SN74LVCH16646ADL equivalent, key selection criteria include its dual-clock register architecture, I_off partial-power-down support, 56-pin SSOP (DL) package, and guaranteed 3.3-V timing performance across –40°C to 85°C.

Technical Context

The SN74LVCH16646ADL integrates two independent 8-bit transceiver channels, each with D-type flip-flops clocked by separate CLKAB/CLKBA inputs and controlled by DIR, OE, SAB/SBA signals. Its logic diagram confirms fully synchronous registration: data on A or B buses is latched only on low-to-high clock transitions, with no transparent pass-through during clock hold.

It implements true bidirectional 3-state control per channel-OE disables outputs while preserving input functionality, and DIR selects direction (A→B or B→A) only when OE is active low. The device uses bus-hold circuitry instead of external resistors and meets JESD 17 latch-up (>250 mA) and JESD 22 ESD (2000-V HBM) requirements.

Key Specifications

Pinout & Package

SN74LVCH16646ADL uses a 56-pin Shrink Small-Outline Package (SSOP-DL), 13.9 mm × 7.9 mm × 1.2 mm body, with 0.5 mm lead pitch and gull-wing leads. Pin 1 is marked in top-left corner of package; seating plane defines mechanical reference.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit registered transceiver applications.

Compared with SN74LVC16646ADL and 74ALVCH16646DL, the SN74LVCH16646ADL uniquely combines 5-V input tolerance, integrated bus-hold, and active production assurance-making it the robust choice for mixed-voltage industrial and telecom infrastructure where reliability and long-term supply continuity are mandatory.

Availability

SN74LVCH16646ADL is available at Aetrix Electronics and suitable for industrial backplane interfaces, memory-mapped I/O bridges, hot-swappable module interfaces, and multi-processor data coherency links requiring stable component supply across extended product lifecycles.

Supply support for SN74LVCH16646ADL 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 SN74LVCH16646ADL belongs to TI's Widebus™ family of advanced bus-interface devices, engineered specifically for high-speed, mixed-voltage, and hot-swap-capable industrial and communications systems.

FAQ

What is the maximum clock frequency supported by the SN74LVCH16646ADL in registered mode?

The SN74LVCH16646ADL supports up to 150 MHz clock frequency in registered mode, as confirmed by timing parameter f_clock = 150 MHz at V_CC = 2.7 V and 3.3 V. This rating applies to both CLKAB and CLKBA inputs and ensures reliable data capture under worst-case process/voltage/temperature conditions.

Does the SN74LVCH16646ADL require external pullup resistors on its control inputs?

No, the SN74LVCH16646ADL does not require external pullup resistors on DIR, OE, SAB, SBA, or clock inputs. All control inputs have internal weak pullup/pulldown structures specified in the datasheet, and TI explicitly recommends holding unused controls at V_CC or GND-not through external resistors-to ensure proper operation.

Can the SN74LVCH16646ADL operate with V_CC = 1.8 V while interfacing with 5-V logic?

Yes, the SN74LVCH16646ADL operates with V_CC = 1.8 V and accepts input voltages up to 5.5 V on all A/B port and control pins. This allows direct connection to 5-V TTL or CMOS outputs without level-shifting circuitry, making it ideal for upgrading legacy systems to lower core voltages while retaining compatibility.

How does the bus-hold feature of the SN74LVCH16646ADL function during power-up?

The bus-hold circuitry in the SN74LVCH16646ADL activates immediately upon V_CC reaching ~1.2 V and maintains undriven A/B port inputs at their last-valid logic state. TI specifies that bus-hold current remains within ±75 µA across the full operating range, eliminating floating inputs without external components during power-rail ramp-up sequences.

Is the SN74LVCH16646ADL pin-compatible with the SN74LVCH16646ADLR?

Yes, the SN74LVCH16646ADL (tube) and SN74LVCH16646ADLR (tape-and-reel) share identical electrical specifications, pinout, package dimensions, and thermal characteristics-both use the 56-pin SSOP-DL package. The only difference is packaging format; they are functionally and mechanically interchangeable in PCB layout.