Texas Instruments SN74CBT16211ADL

Overview

SN74CBT16211ADL from Texas Instruments is a 24-bit high-speed TTL-compatible bus switch IC in SSOP-56 package, featuring 5 Ω typical on-state resistance, 0.25 ns propagation delay at 5 V, and dual 12-bit or single 24-bit configurable switching for memory expansion and data path isolation in industrial control backplanes.

For engineers reviewing the SN74CBT16211ADL datasheet, SN74CBT16211ADL pinout, SN74CBT16211ADL application, or SN74CBT16211ADL equivalent, key selection criteria include low on-resistance matching, TTL-level enable compatibility, 56-pin SSOP thermal performance (θ_JA = 56°C/W), and dual-bus switching logic with independent OE control.

Technical Context

The SN74CBT16211ADL implements two independent 12-bit bidirectional analog switches controlled by separate OE pins (1OE and 2OE), enabling selective connection of A-side to B-side ports without directionality constraints. Each switch operates with minimal voltage drop due to its low 5–7 Ω r_on across the full 4–5.5 V supply range.

It supports TTL-compatible input thresholds (V_IL ≤ 0.8 V, V_IH ≥ 2 V) and delivers sub-nanosecond timing: t_pd = 0.25 ns (V_CC = 5 V), t_en = 3.3 ns, and t_dis = 2.8 ns into 50 pF load - critical for high-throughput address/data bus isolation in legacy parallel interfaces.

Key Specifications

Pinout & Package

SN74CBT16211ADL uses a 56-pin SSOP (DL) package with 0.635 mm pitch, 13.9 mm × 7.4 mm body, and 1.2 mm max height. Pin 1 is located at top-left corner with index area marking.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus switching applications.

Compared with SN74CBT16211ADL, SN74CBTD16211DGGR trades speed and thermal performance for smaller footprint, while SN74CB3Q16211DGVR improves conduction loss and ruggedness at higher cost - both require validation of enable timing and layout decoupling.

Availability

SN74CBT16211ADL is available at Aetrix Electronics and suitable for industrial backplane isolation, memory expansion interfaces, legacy parallel peripheral bridging, and automated test equipment signal routing requiring stable component supply across extended product lifecycles.

Supply support for SN74CBT16211ADL 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 SN74CBT16211ADL belongs to TI's Widebus™ family of high-speed bus switches, engineered specifically for low-latency, bidirectional signal routing in legacy parallel bus architectures and modular system interconnects.

FAQ

What is the maximum operating temperature for the SN74CBT16211ADL?

The SN74CBT16211ADL is rated for operation from −40°C to +85°C ambient temperature. Its SSOP-56 package exhibits θ_JA = 56°C/W, so junction temperature remains within safe limits under typical 128 mA channel loading and proper PCB copper pour. Always verify thermal design using TI's thermal simulation guidelines in SLMA002.

Does the SN74CBT16211ADL require external pull-up or pull-down resistors on its OE pins?

Yes - the SN74CBT16211ADL requires all unused control inputs, including 1OE and 2OE, to be held at either V_CC or GND to ensure predictable switching behavior. TI Application Report SCBA004 mandates this to prevent floating inputs from inducing shoot-through current or metastable states in the internal logic.

Can the SN74CBT16211ADL interface between 3.3 V and 5 V logic domains?

The SN74CBT16211ADL supports bidirectional signal translation between 3.3 V and 5 V domains because its I/O pins tolerate −0.5 V to 7 V and its TTL-compatible inputs recognize 2.0 V as high regardless of V_CC. However, V_CC must be set to the higher domain (5 V) to guarantee full output swing and r_on specification.

What is the meaning of "NC" pins on the SN74CBT16211ADL pinout?

"NC" stands for No internal connection - pins 1 and 56 on the SN74CBT16211ADL are physically present for mechanical stability and alignment but have no electrical connection to die circuitry. These pins must remain unconnected on the PCB to avoid unintended coupling or solder bridging that could compromise signal integrity.

How does the SN74CBT16211ADL differ from standard digital logic gates in bus switching applications?

Unlike digital gates, the SN74CBT16211ADL functions as an analog pass-gate switch with near-zero propagation delay and bidirectional signal flow - it does not regenerate logic levels or invert signals. Its 5 Ω r_on preserves analog waveform fidelity and eliminates timing skew between parallel lines, making it ideal for high-fidelity data/address bus isolation where logic gates would add latency and voltage drop.