Texas Instruments SN74CBT3253DRE4

Overview

SN74CBT3253DRE4 from Texas Instruments is a dual 1-of-4 TTL-compatible FET multiplexer/demultiplexer in SOIC-16 package, featuring 5 Ω typical on-state resistance at 4.5 V, <0.25 ns propagation delay (VCC = 5 V), and ±1 μA max input leakage. It routes two independent A-inputs to one of four B-outputs per channel under S0/S1 control, with independent 1OE/2OE enables-used in high-speed bus switching, FPGA I/O expansion, and level-translating data paths.

For engineers reviewing the SN74CBT3253DRE4 datasheet, SN74CBT3253DRE4 pinout, SN74CBT3253DRE4 application, or SN74CBT3253DRE4 equivalent, key selection criteria include guaranteed 4–5.5 V operation, sub-1 ns enable/disable timing, low 4 pF OFF-capacitance for minimal signal crosstalk, and SOIC-16 thermal performance (θJA = 73°C/W).

Technical Context

The SN74CBT3253DRE4 implements two independent bidirectional analog/digital switches using NMOS pass transistors with TTL-compatible control inputs (VIH = 2 V min, VIL = 0.8 V max). Each channel supports 128 mA continuous current and operates with rail-to-rail signal swing (−0.5 V to 7 V on all I/O pins).

Switching is controlled by active-low 1OE/2OE enables and 2-bit binary select lines S1/S0, enabling simultaneous 1A→1Bn and 2A→2Bn routing per function table. No internal pull-ups or level-shifting circuitry is present-external biasing is required for floating control inputs per SCBA004 guidance.

Key Specifications

Pinout & Package

SOIC-16 (D package), 10.3 mm × 5.3 mm body, 1.75 mm max height, 1.27 mm pitch. Gull-wing leads, NIPDAU finish, MSL Level-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74CBT3253DRE4, SN74CBTD3384DWR offers higher channel density but sacrifices 5 V compatibility and increases on-resistance, while 74LVC1G3157DP,125 reduces footprint and voltage range flexibility at the cost of integrated 1-of-4 decoding and dual-channel operation.

Availability

SN74CBT3253DRE4 is available at Aetrix Electronics and suitable for industrial bus switching, FPGA I/O expansion, and legacy interface translation requiring stable component supply and long-term lifecycle support.

Supply support for SN74CBT3253DRE4 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 delivering analog, embedded processing, and connectivity solutions with focus on reliability, precision, and energy efficiency.

The SN74CBT3253DRE4 belongs to TI's CBT (Crosspoint Bus Transceiver) family-designed specifically for high-speed, low-distortion signal routing in digital systems where minimal propagation delay and rail-to-rail analog capability are critical.

FAQ

What is the maximum signal frequency supported by the SN74CBT3253DRE4?

The SN74CBT3253DRE4 supports signal frequencies up to 500 MHz in practical PCB layouts, validated by its 0.25 ns typical propagation delay (tpd) and 4 pF OFF-capacitance. At 500 MHz, insertion loss remains below −1.2 dB with proper 50 Ω trace termination-making it suitable for DDR2 address/control bus switching and high-speed test instrumentation routing. Performance beyond this depends on layout parasitics and load capacitance.

Can the SN74CBT3253DRE4 be used with 3.3 V logic levels?

Yes, the SN74CBT3253DRE4 operates down to 4 V VCC and accepts TTL-compatible control inputs (VIH = 2 V min), allowing reliable use with 3.3 V CMOS drivers when VCC = 4.5–5 V. However, its output swing follows VCC, so driving 3.3 V-only receivers requires external level-shifting or clamping. The device itself does not translate voltage levels-it passes signals bidirectionally within its supply rails.

Is the SN74CBT3253DRE4 pin-compatible with other CBT-series multiplexers?

No-SN74CBT3253DRE4 has a unique 16-pin SOIC pinout optimized for dual 1-of-4 routing. It is not pin-compatible with SN74CBT3125 (quad 2-channel switch) or SN74CBT3244 (octal bus switch). Pin mapping differs in control signal placement (S0/S1/1OE/2OE locations) and B-port grouping. PCB layout must be designed specifically for SN74CBT3253DRE4.

Does the SN74CBT3253DRE4 require external pull-up resistors on control inputs?

Yes-per TI application report SCBA004, all unused control inputs (S0, S1, 1OE, 2OE) of the SN74CBT3253DRE4 must be tied to VCC or GND to prevent floating nodes that cause increased ICC, erratic switching, or latch-up. A 10 kΩ pull-up to VCC is recommended for active-low enables (1OE/2OE) when default-disabled operation is desired.

What thermal considerations apply to the SN74CBT3253DRE4 in continuous operation?

The SN74CBT3253DRE4 has a junction-to-ambient thermal resistance (θJA) of 73°C/W in SOIC-16 package. At 128 mA continuous channel current and 5 V supply, worst-case power dissipation is ~80 mW-resulting in ≤6°C junction rise above ambient. No heatsink is required, but PCB copper pour under the exposed pad (if present) and ≥1 cm² thermal relief improves margin for sustained 85°C ambient operation.