Texas Instruments SN74CBT16861DGGR

Overview

SN74CBT16861DGGR from Texas Instruments is a 20-bit FET bus switch organized as two independent 10-bit switches, featuring 5-Ω on-state resistance, TTL-compatible control inputs (VIH = 2 V, VIL = 0.8 V), and operation across –40°C to 85°C. It enables high-speed bidirectional signal routing in memory expansion, data multiplexing, and hot-swap I/O buffering applications.

For engineers reviewing the SN74CBT16861DGGR datasheet, SN74CBT16861DGGR pinout, SN74CBT16861DGGR application, or SN74CBT16861DGGR equivalent, key selection criteria include low propagation delay (0.25 ns at 5 V), high-impedance isolation during disable, latch-up immunity (>100 mA per JESD 78 Class II), and TSSOP-48 packaging for space-constrained PCB layouts.

Technical Context

The SN74CBT16861DGGR implements dual 10-bit FET-based analog switches with separate OE controls per bank. Each switch operates as a voltage-controlled pass gate with no internal logic-signal integrity depends solely on Ron (5–7 Ω) and Cio(OFF) (5.5 pF).

It uses standard CMOS process technology with TTL-level input thresholds and supports rail-to-rail analog/digital signal switching up to 5.5 V. No level translation or biasing is required; A/B ports are fully bidirectional and electrically symmetrical.

Key Specifications

Pinout & Package

TSSOP-48 package (DGG), 12.6 mm × 6.2 mm × 1.2 mm max height, JEDEC MO-153 compliant, lead-free NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT16861DGGR, SN74CBTD16210DGGR trades 5-V compatibility and lower Ron for higher density, while 74ALVC164245DGGR introduces direction control and voltage translation at the cost of added complexity and reduced analog transparency.

Availability

SN74CBT16861DGGR is available at Aetrix Electronics and suitable for memory expansion, hot-swap I/O buffering, and legacy bus isolation requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant TSSOP packaging.

Supply support for SN74CBT16861DGGR 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 high-speed interface solutions.

The SN74CBT16861DGGR belongs to TI's Widebus™ family of FET bus switches, designed specifically for low-latency, low-distortion signal routing in industrial, computing, and communications infrastructure where deterministic timing and robustness are critical.

FAQ

What is the maximum continuous current rating per channel for the SN74CBT16861DGGR?

The SN74CBT16861DGGR supports a continuous channel current of 128 mA per switch path, verified under absolute maximum ratings. This allows reliable operation with typical digital bus loads (e.g., 50–100 mA per line in 5-V TTL systems) while maintaining specified on-resistance and thermal performance within the –40°C to 85°C operating range. Exceeding this limit risks thermal runaway or parametric shift in SN74CBT16861DGGR performance.

Does the SN74CBT16861DGGR support bidirectional signal flow on each A–B pair?

Yes, the SN74CBT16861DGGR provides true bidirectional analog/digital signal routing between each A and B terminal pair - no direction pin or internal logic controls signal polarity. The device functions as a passive FET pass gate, meaning voltage and current can flow equally from A to B or B to A when enabled. This behavior is intrinsic to the SN74CBT16861DGGR architecture and confirmed in its functional description and logic diagram.

Can the SN74CBT16861DGGR operate with a 3.3-V supply?

No - the SN74CBT16861DGGR is specified only for 4 V to 5.5 V operation per recommended conditions. At 3.3 V, the device fails to meet VIH/VIL thresholds (2 V/0.8 V), resulting in undefined switching behavior and potential output contention. For 3.3-V systems, TI recommends alternatives like SN74CBTD16210DGGR, but SN74CBT16861DGGR requires strict adherence to its 4–5.5 V supply window.

How does the latch-up immunity of the SN74CBT16861DGGR benefit industrial applications?

The SN74CBT16861DGGR exceeds 100 mA latch-up immunity per JESD 78 Class II, meaning it withstands transient current faults - such as ESD events, power sequencing glitches, or short-duration bus contention - without entering destructive latch-up. This makes SN74CBT16861DGGR suitable for ruggedized industrial controllers, programmable logic systems, and field-deployed equipment where reliability under electrical stress is non-negotiable.

Are the two OE inputs on the SN74CBT16861DGGR functionally isolated?

Yes - 1OE and 2OE are fully independent control inputs, each enabling only its associated 10-bit switch bank (1A↔1B or 2A↔2B). There is no internal coupling or dependency between them. This allows granular bus segmentation - for example, holding memory address lines active while disabling data lines during write cycles - a capability confirmed in the function table and logic diagram of the SN74CBT16861DGGR datasheet.