Texas Instruments SN74CBT16212ADGG

Overview

SN74CBT16212ADGG from Texas Instruments is a 24-bit FET bus-exchange switch operating as either a 24-bit bus switch or a 12-bit bus exchanger, with 5-Ω on-state resistance, TTL-compatible input levels, and operation from –40°C to 85°C. It enables bidirectional data exchange between four signal ports (A1/A2/B1/B2) via S0–S2 select inputs in industrial control backplanes and memory expansion interfaces.

For engineers reviewing the SN74CBT16212ADGG datasheet, SN74CBT16212ADGG pinout, SN74CBT16212ADGG application, or SN74CBT16212ADGG equivalent, key selection criteria include its 4–5.5 V supply range, sub-1 ns propagation delay at 4 V, 128 mA continuous channel current rating, and DGG package compatibility with high-density PCB layouts.

Technical Context

The SN74CBT16212ADGG implements a CMOS-based FET switch architecture with independent A/B port pairs controlled by three select lines (S0, S1, S2), supporting eight distinct connection states including full disconnect and cross-port exchange. Its low on-resistance (4–7 Ω typical) and minimal charge injection ensure signal integrity for TTL-level digital buses.

It features latch-up immunity exceeding 250 mA per JESD 17 and ESD protection >2000 V per MIL-STD-833 Method 3015. The device operates without internal level-shifting circuitry and requires all unused control inputs tied to VCC or GND to prevent floating-node instability.

Key Specifications

Pinout & Package

The SN74CBT16212ADGG is housed in a 56-pin Thin Shrink Small-Outline (DGG) package with 0.5-mm lead pitch and exposed pad for thermal enhancement. Pin numbering follows standard top-view orientation with GND and VCC distributed across multiple pins for low-impedance power delivery.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBTD16212DGGR and 74LVC16212DGGR, the SN74CBT16212ADGG offers native 5-V tolerance, zero bus-hold overhead, and direct compatibility with legacy TTL infrastructure-making it optimal for retrofitting or mixed-voltage industrial backplanes where signal integrity and voltage margin are primary concerns.

Availability

SN74CBT16212ADGG is available at Aetrix Electronics and suitable for industrial backplane switching, memory expansion interfaces, test access multiplexing, and legacy bus bridging requiring stable component supply across extended product lifecycles.

Supply support for SN74CBT16212ADGG 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 90 years of innovation in industrial, automotive, and communications markets.

The CBT (Crosspoint Bus Transceiver) family, including the SN74CBT16212ADGG, was engineered for high-speed, low-distortion digital signal routing in 5-V systems-targeting applications demanding minimal propagation delay, robust ESD/latch-up performance, and seamless integration with legacy TTL infrastructure.

FAQ

What is the maximum continuous current rating per channel for the SN74CBT16212ADGG?

The SN74CBT16212ADGG supports a continuous channel current of 128 mA per switched path. This rating is specified under recommended operating conditions (VCC = 4–5.5 V, TA = –40°C to 85°C) and reflects the maximum DC current the internal FET can sustain without exceeding thermal or reliability limits. Exceeding this value risks increased on-resistance drift or long-term degradation. The SN74CBT16212ADGG datasheet confirms this in the Absolute Maximum Ratings table.

Does the SN74CBT16212ADGG require external pull-up or pull-down resistors on its S0–S2 control inputs?

No, the SN74CBT16212ADGG does not require external pull-up or pull-down resistors on S0–S2, but all unused control inputs must be actively held at VCC or GND to prevent floating states that could cause undefined switching behavior. TI's application report SCBA004 explicitly mandates this practice. The SN74CBT16212ADGG has no internal bus-hold circuitry, so external biasing is necessary only when inputs are left unconnected-not during normal operation.

Can the SN74CBT16212ADGG operate reliably at 3.3 V?

No, the SN74CBT16212ADGG is not characterized for reliable operation at 3.3 V. Its recommended operating supply range is strictly 4 V to 5.5 V, and electrical characteristics-including on-state resistance, propagation delay, and input thresholds-are only guaranteed within that window. Attempting 3.3-V operation may result in marginal VIH/VIL margins, increased Ron, or functional failure. For 3.3-V systems, consider the 74LVC16212DGGR instead of the SN74CBT16212ADGG.

How many distinct connection states does the SN74CBT16212ADGG support via its S0–S2 inputs?

The SN74CBT16212ADGG supports eight distinct connection states defined by the S0–S2 select inputs, as shown in the Function Table of its datasheet. These include full disconnect (two states), 12-bit port-to-port connections (four states), and bidirectional cross-exchange modes (two states). Each state configures specific A/B port pairings without overlap or ambiguity. The SN74CBT16212ADGG uses positive logic decoding, with 'L' = low and 'H' = high referenced to GND and VCC respectively.

Is the SN74CBT16212ADGG pin-compatible with the SN74CBTD16212DGGR?

Yes, the SN74CBT16212ADGG and SN74CBTD16212DGGR share identical pinouts and DGG package dimensions (56-pin, 0.5-mm pitch), making them mechanically interchangeable. However, the SN74CBTD16212DGGR adds bus-hold circuitry on all I/O pins, resulting in slightly higher supply current and ~0.5 ns longer propagation delay. The SN74CBT16212ADGG remains the preferred choice when bus-hold functionality is unnecessary and minimal delay is critical.