Texas Instruments SN74CBT16244CDLR

Overview

SN74CBT16244CDLR 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. It enables bidirectional signal routing between port A and port B with minimal propagation delay (0.25 ns typical at VCC = 5 V), used in high-speed digital backplane and memory interface isolation.

For engineers reviewing the SN74CBT16244CDLR datasheet, SN74CBT16244CDLR pinout, SN74CBT16244CDLR application, or SN74CBT16244CDLR equivalent, key selection criteria include on-resistance stability across voltage range, OE-controlled high-impedance isolation timing (tdis ≤ 5.4 ns), thermal performance in SSOP-48 package, and compatibility with 3.3 V/5 V mixed-signal bus architectures.

Technical Context

The SN74CBT16244CDLR implements four independent bilateral FET switches per 4-bit segment, each controlled by a dedicated active-low output-enable (OE) input. Its MOSFET-based architecture delivers symmetrical conduction between A and B ports without directionality constraints.

Switch operation is governed by OE logic level: OE = low enables low-resistance path (ron ≤ 7 Ω at VCC = 4.5 V, II = 30 mA); OE = high forces >10⁹ Ω isolation between ports. Propagation delay is determined solely by RC time constant of on-resistance and load capacitance, not internal logic gates.

Key Specifications

Pinout & Package

SN74CBT16244CDLR uses 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. Pin 1 is located at top-left corner with notch or beveled edge marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT16244CDLR, SN74CBTD16212DLR adds voltage translation at the cost of increased on-resistance and reduced speed, while SN74LVC16244ADGGR provides stronger drive but lacks true bidirectional analog switching-making SN74CBT16244CDLR optimal for low-latency, symmetric bus coupling in 5 V systems.

Availability

SN74CBT16244CDLR is available at Aetrix Electronics and suitable for industrial control backplanes, telecom line-card interconnects, and test instrumentation requiring stable component supply with long-term lifecycle support.

Supply support for SN74CBT16244CDLR 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 company headquartered in Dallas, Texas, delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74CBT16244CDLR belongs to TI's Widebus™ family of high-speed bus switches, designed specifically for low-latency, bidirectional signal routing in 5 V digital systems where minimal propagation delay and precise timing control are critical.

FAQ

What is the maximum continuous current rating per channel for SN74CBT16244CDLR?

The SN74CBT16244CDLR supports a continuous channel current of 128 mA per switch path, verified under recommended operating conditions (VCC = 4 V to 5.5 V, TA = –40°C to +85°C). This rating applies to steady-state DC conduction when OE is asserted low and both A and B terminals are within valid voltage ranges. Exceeding this current may cause thermal derating or permanent damage.

Does SN74CBT16244CDLR support hot-swap operation without external protection circuitry?

Yes, SN74CBT16244CDLR supports hot-swap operation due to its overvoltage-tolerant I/O structure: inputs and outputs withstand –0.5 V to 7 V regardless of VCC state, and VIH/VIL thresholds remain valid during power ramp-up. No external clamping diodes or sequencing circuits are required, making it suitable for live-insertion applications like modular backplanes and field-replaceable units.

How does the on-state resistance (ron) of SN74CBT16244CDLR vary with supply voltage and signal level?

SN74CBT16244CDLR exhibits ron = 5–7 Ω at VCC = 4.5 V with VI = 0 V and II = 30 mA, and ron = 8–12 Ω when VI = 2.4 V under same current. At VCC = 4 V, ron increases slightly to 5–10 Ω. This voltage-dependent behavior stems from MOSFET channel modulation and must be accounted for in precision analog switching or low-voltage digital applications where voltage drop impacts signal fidelity.

Can SN74CBT16244CDLR be used to isolate I²C or SMBus signals?

No, SN74CBT16244CDLR is not recommended for I²C or SMBus isolation because its 5–12 Ω on-resistance introduces excessive voltage drop across pull-up resistors, violating bus voltage thresholds. Additionally, its lack of built-in slew-rate control and undefined behavior during partial power-down states can corrupt open-drain signaling. Dedicated I²C bus switches like TCA9548A are preferred for such protocols.

What is the thermal performance of SN74CBT16244CDLR in its SSOP-48 package?

SN74CBT16244CDLR in SSOP-48 (DL package) has a junction-to-ambient thermal impedance (θJA) of 63°C/W under standard JEDEC PCB mounting conditions. At full 128 mA per channel and ambient temperature of 85°C, junction temperature remains below 150°C - within safe operating limits. For sustained high-current operation, use of thermal vias and copper pour under exposed pad (if present) is advised, though DL package lacks thermal pad.