Texas Instruments SN74CBTD16211DLR

Overview

SN74CBTD16211DLR from Texas Instruments is a 24-bit FET bus switch with integrated level shifting, designed for bidirectional 5-V-to-3.3-V signal translation between TTL-compatible buses. It features dual 12-bit independent channels, 5-Ω on-state resistance, sub-1 ns propagation delay, and operates across –40°C to 85°C. It serves in high-speed memory/data bus isolation and mixed-voltage system interconnects.

For engineers reviewing the SN74CBTD16211DLR datasheet, SN74CBTD16211DLR pinout, SN74CBTD16211DLR application, or SN74CBTD16211DLR equivalent, key selection criteria include its dual OE-controlled 12-bit switching architecture, guaranteed 5-Ω r_on, level-shifting diode integration, SSOP-56 thermal performance (θ_JA = 56°C/W), and compatibility with fast-edge, high-frequency digital interfaces requiring minimal signal degradation.

Technical Context

The SN74CBTD16211DLR implements two independent 12-bit FET-based transmission gates, each controlled by a dedicated output-enable (OE) input. Its internal diode-to-V_CC structure enables passive level shifting from 5-V inputs to 3.3-V outputs without external components.

It operates under 4.5 V–5.5 V supply, supports TTL-compatible control inputs (V_IL ≤ 0.8 V, V_VIH ≥ 2 V), and maintains high-impedance isolation when OE is high. Switching is bidirectional, with propagation delay (t_pd) as low as 0.25 ns and enable/disable times under 10 ns at C_L = 50 pF.

Key Specifications

Pinout & Package

SN74CBTD16211DLR is housed in a 56-pin Plastic Small-Outline Package (SSOP-DL), 11.4 mm × 7.5 mm body size, 1.2 mm max height, JEDEC MO-118 compliant, with 0.5-mm lead pitch and gull-wing leads.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD16211DLR, SN74CBT16211DGGR offers identical functionality in a smaller TSSOP package but with reduced thermal performance, while SN74CBTD16210DLR provides half the channel count and simplified control - both require no schematic changes but differ in scalability and thermal management trade-offs.

Availability

SN74CBTD16211DLR is available at Aetrix Electronics and suitable for memory bus isolation, processor-peripheral interfacing, backplane routing, and test equipment channel multiplexing requiring stable component supply and industrial temperature operation.

Supply support for SN74CBTD16211DLR 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 decades of expertise in logic and interface solutions.

The SN74CBTD16211DLR belongs to TI's Widebus™ family of high-speed bus switches, engineered specifically for low-latency, level-shifting interconnects in mixed-voltage digital systems.

FAQ

What is the maximum continuous current per channel for the SN74CBTD16211DLR?

The SN74CBTD16211DLR supports a continuous channel current of 128 mA per switch path, as specified in its absolute maximum ratings. This rating applies under recommended operating conditions (V_CC = 4.5 V to 5.5 V, T_A = –40°C to 85°C) and ensures reliable conduction without thermal runaway or parametric shift. Exceeding this current may degrade r_on stability or accelerate wear-out.

Does the SN74CBTD16211DLR require external pull-up or pull-down resistors on its control inputs?

No - the SN74CBTD16211DLR does not require external pull-up or pull-down resistors on its OE inputs, provided they are actively driven to valid TTL logic levels (V_IL ≤ 0.8 V, V_IH ≥ 2 V). However, TI explicitly states that all unused control inputs must be held at V_CC or GND to prevent floating nodes and ensure proper device operation.

Can the SN74CBTD16211DLR perform 3.3-V-to-5-V level shifting?

No - the SN74CBTD16211DLR is designed specifically for 5-V-to-3.3-V level shifting via its integrated diode-to-V_CC structure. Driving 3.3-V signals into Port A or B while V_CC = 5 V does not activate the level-shifting mechanism in reverse; bidirectional signal flow is supported, but voltage translation occurs only from higher- to lower-voltage side.

What is the meaning of "NC" on pins 1 and 56 of the SN74CBTD16211DLR?

"NC" stands for "No internal connection" - pins 1 and 56 of the SN74CBTD16211DLR have no electrical connection to the die. They serve only mechanical anchoring and package integrity functions. These pins must remain unconnected in PCB layout; routing traces or applying solder to them may cause mechanical stress or unintended coupling.

How does the SN74CBTD16211DLR handle fast edge rates and high-frequency switching?

The SN74CBTD16211DLR maintains signal integrity at high frequencies due to its 5-Ω r_on, 0.25 ns propagation delay, and low off-capacitance (C_io(OFF) = 5.5 pF). However, TI notes that in applications with fast edge rates, multiple simultaneous outputs switching, or very high frequencies, the level-shifting effect may diminish - so it should be validated in-system with actual load and routing conditions.