Texas Instruments SN74CBT16244DL

Overview

SN74CBT16244DL from Texas Instruments is a 16-bit FET bus switch IC organized as four independent 4-bit low-impedance switches, featuring 5-Ω on-state resistance, TTL-compatible input levels, and standard '16244-type pinout - used for high-speed bidirectional signal routing in memory expansion, data bus isolation, and hot-swap interface circuits.

For engineers reviewing the SN74CBT16244DL datasheet, SN74CBT16244DL pinout, SN74CBT16244DL application, or SN74CBT16244DL equivalent, key selection criteria include on-resistance (5–7 Ω), propagation delay (≤0.35 ns at VCC = 5 V), supply voltage range (4–5.5 V), thermal impedance (63°C/W), and SSOP-48 package compatibility with industrial temperature operation (–40°C to 85°C).

Technical Context

The SN74CBT16244DL implements four independent 4-bit analog bus switches using NMOS FETs with no internal level-shifting circuitry; each switch is controlled by a dedicated OE input that enables bidirectional conduction between A and B ports when low. Its architecture avoids CMOS latch-up risk and supports hot-insertion due to high-impedance isolation when disabled.

It operates without internal biasing or charge pumps - relying solely on VCC-supplied gate drive - and maintains signal integrity via low capacitance (Cio(OFF) = 4.5 pF) and minimal propagation delay (tpd ≤ 0.35 ns), making it suitable for TTL-level parallel bus applications requiring minimal timing skew and low power consumption (ICC ≤ 3 µA).

Key Specifications

Pinout & Package

SN74CBT16244DL is housed in a 48-pin SSOP (Shrink Small Outline Package) with 0.5-mm pitch, 12.6 mm × 6.2 mm body size, and 1.2-mm max height - optimized for high-density PCB layouts while maintaining hand-solderability and reflow compatibility (MSL Level-1, 260°C peak).

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT16244DGGR and SN74CBTD16211DL, the SN74CBT16244DL offers tube-packaged SSOP-48 delivery ideal for prototyping and low-volume industrial builds, retains identical 5-Ω RON and 0.35-ns tpd, but trades slightly higher thermal resistance (63°C/W) for mechanical robustness and ease of manual handling.

Availability

SN74CBT16244DL is available at Aetrix Electronics and suitable for memory expansion interfaces, hot-swap backplane modules, and legacy TTL system interfacing requiring stable component supply, long-term industrial lifecycle support, and RoHS-compliant SSOP packaging.

Supply support for SN74CBT16244DL 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 digital signal technologies, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74CBT16244DL belongs to TI's Widebus™ family of high-speed bus switches - designed specifically for low-latency, bidirectional signal routing in 5-V TTL environments where timing predictability and signal fidelity are critical.

FAQ

What is the maximum continuous current rating per channel for the SN74CBT16244DL?

The SN74CBT16244DL supports a continuous channel current of 128 mA per switch path, verified under absolute maximum ratings. This value reflects the device's ability to sustain conduction without thermal runaway when operated within its recommended 4–5.5 V supply range and –40°C to 85°C ambient temperature. Exceeding this current may degrade on-resistance stability or accelerate electromigration in the FET channel.

Does the SN74CBT16244DL require external pull-up or pull-down resistors on its OE inputs?

No, the SN74CBT16244DL does not require external pull-up or pull-down resistors on its OE inputs. The device specifies VIH = 2 V and VIL = 0.8 V, making it fully compatible with standard 5-V TTL logic outputs. However, TI recommends tying unused OE inputs directly to VCC or GND to prevent floating states that could cause unintended switching or increased ICC.

Can the SN74CBT16244DL be used in 3.3-V systems?

The SN74CBT16244DL is not rated for reliable operation below 4 V supply voltage per its recommended operating conditions. While some marginal functionality may occur at 3.3 V, parameters like on-resistance (increasing beyond 10 Ω), propagation delay (exceeding 1 ns), and input threshold margins become unguaranteed. For 3.3-V systems, TI recommends the SN74CB3Q16244 or SN74AVC16244 families instead.

How many independent enable controls does the SN74CBT16244DL provide?

The SN74CBT16244DL provides four independent output-enable (OE) inputs - labeled 1OE through 4OE - each controlling one 4-bit switch bank. This allows granular isolation of address, data, or control bus segments without affecting other channels, supporting flexible partitioning in multi-peripheral architectures.

Is the SN74CBT16244DL pin-compatible with older 74-series bus switches like the 74LS244?

No, the SN74CBT16244DL is not pin-compatible with the 74LS244. Although both are 16-bit buffer/switch devices, the SN74CBT16244DL uses a 48-pin SSOP package with dual-port A/B topology and active-low OE per 4-bit group, whereas the 74LS244 uses a 20-pin DIP/SOIC package with unidirectional 3-state outputs and two 8-bit groups. Their pinouts, electrical behavior, and functional architecture differ fundamentally.